Question: Not a mechanism of Action of Insulin

INSULIN is a protein hormone formed from proinsulin in the beta cells of the pancreatic islets of Langerhans. The major fuel-regulating hormone, it is secreted into the blood in response to a rise in concentration of blood glucose or amino acids. Insulin promotes the storage of glucose and the uptake of amino acids, increases protein and lipid synthesis, and inhibits lipolysis and gluconeogenesis.Tyrosine kinase is any of a group of enzymes that influence signaling between cells, esp. as relates to cell growth and death, cellular adhesion and movement, and cellular differentiation. Abnormalities in tyrosine kinases are found in some human diseases, including chronic myeloid (myelogenous) leukemia.Glucose transpoer type 4, also known as GLUT4, is a protein that in humans is encoded by the GLUT4 gene. GLUT4 is the insulin-regulated glucose transpoer found in adipose tissues and striated muscle (skeletal and cardiac) that is responsible for insulin-regulated glucose transpo into the cell. This protein is expressed primarily in muscle and fat cells, the major tissues in the body that respond to insulin.Na+, K+-ATPase is an enzyme that spans the plasma membrane and hydrolyzes ATP to provide the energy necessary to drive the cellular sodium pump.Hexokinase an enzyme that catalyzes the transfer of a high-energy phosphate group of a donor to d-glucose, producing d-glucose-6-phosphate.Ref: Ganong&;s review of medical physiology;24th edition; page no-436


Question: Window of limbic system

Amygdala is considered as window of limbic system Ref: guyton and hall textbook of medical physiology 12 edition page number: 826,827,828


Question: Pain and temperature in thalamus is controlled by nucleus

Ans. (b) VPL(Ref: Ganong, 25th ed/p.269)Ventral posterior lateral (VPL) and ventral posteromedial nuclei (VPM) - Transmit somatosensory information to sensory cortex


Question: Poiseuifte's law is

By integrating the velocities of all the concentric rings of flowing blood and multiplying them by the areas of the rings, one can derive the following formula, known as Poiseuille's law: in which F is the rate of blood flow, DP(PA-PB) is the pressure difference between the ends of the vessel, r is the radius of the vessel, l is length of the vessel, and e is viscosity of the blood. F = (PA - PB) pr4/8e4 Ref: Guyton and Hall Textbook of Medical Physiology (12th Edn) page No:309


Question: The basal body temperature shift after ovulation is due to

Your body temperature dips a bit just before your ovary releases an egg. Then, 24 hours after the egg's release, your temperature rises and stays up for several days. Before ovulation, a woman's BBT averages between36.1degC (97degF) and36.4degC (97.5degF). After ovulation, it rises to36.4degC (97.6degF) to37degC (98.6degF). Ref: guyton and hall textbook of medical physiology 12 edition page number:636,637,638


Question: During a voluntary movement, the Golgi tendon organ provides the central nervous system with information about

(D) The tension developed by the muscle being moved # The Golgi tendon organ (GTO) is located in the tendon of skeletal muscles & therefore is in series with the muscle.> Each time the muscle contracts, the tension developed by the muscle causes the GTO to be stretched. It helps to control the tension developed in the muscle.> The 1b afferent fibers, which innervate the GTO, fire in proportion to the amount of GTO stretch, and therefore their firing rate provides the CNS with information about the amount of tension developed by the muscle.> The muscle length and speed of shortening are sent to the CNS by la afferents that innervate the intrafusal fibers within muscle spindles.

The blood flow to the muscle being moved


Question: Golgi tendon apparatus conveys message to CNS depending upon

Detection of Muscle length- Muscle spindle
Detection of Muscle tension- Golgi tendon organ


Question: Hung up reflex is seen

Hung-up reflex is defined as a deep tendon reflex in which, after a stimulus is given and the reflex action takes place, the limb slowly returns to its neutral position. This prolonged relaxation phase is characteristic of reflexes in persons with hypothyroidism.Myxedema a condition resulting from advanced hypothyroidism, or deficiency of thyroxine; it is the adult form of the disease whose congenital form is known as cretinism.Hypehyroidism is defined as the overproduction of thyroid hormones by an overactive thyroid.Hypothyroidism, or underactive thyroid, develops when the thyroid gland fails to produce or secrete as much thyroxine(T4) as the body needs.Pheochromocytoma is a tumor of special cells (called chromaffin cells), most often found in the middle of the adrenal gland.Ref: Ganong&;s review of medical physiology; 24th edition; page no-346


Question: Auditory impulse relays to

(B) Medial geniculate body > The afferent fibers in the auditory division of the eighth cranial nerve end in dorsal and ventral cochlear nuclei.> From there, auditory impulses pass by various routes to the inferior colliculi, the centers for auditory reflexes, and via the medial geniculate body in the thalamus to the auditory cortex.> Other impulses enter the reticular formation. Information from both ears converges on each superior olive, and beyond this, nrnst of the neurons respond to inputs from both sides.> The primary auditory cortex is Brodmann's area 41. In humans, low tones are represented anterolaterally and high tones postero-medially in the auditory cortex.


Question: Urinary concentrating ability of the kidney is increased by

When there is an ECF volume expansion, there is increased renal blood flow and increased GFR. When renal blood flow is more, the solutes in renal medulla are washed off. And this reduces the medullary concentration. Similarly, when increased GFR, Na+ reabsorption power is decreased, this leads to a decrease of the medullary concentration. When ECF volume contraction occurs, the medullary concentration is increased.


Question: Change in the diastolic BP upon standing comes back to normal within

In standing poster diastolic BP increases Upon standing peripheral pooling of blood independent pas occur sudden standing increases DBP,if recorded within 30 to 60 seconds of change in posture after that it comes back to normal where the operation of baroreceptor reflex. Ref: page no-351 Textbook of physiology Volume 1 AK Jain 7th edition


Question: Mean aerial pressure depends upon

Cardiac output and peripheral resistance. As blood is pumped out of the left ventricle into the aoa and distributing aeries, pressure is generated. The mean aerial pressure (MAP) is determined by the cardiac output (CO), systemic vascular resistance (SVR), and central venous pressure (CVP).


Question: Macrophage is CNS

Microglia are scavenger cells in CNS that resemble tissue macrophages and remove debris resulting from the injury. Ganong's review of medical physiology; 23rd edition; pg: 80


Question: Substance (s) freely filtered across glomerular capillaries

Glomerular filtration the renal process whereby fluid in the blood is filtered across the capillaries of the glomerulus and into the urinary space of Bowman&;s capsule. Glucose is freely filtered across glomerular capillaries.Ref: Ganong&;s Review of Medical Physiology; 24th edition; page no: 678


Question: Calcium absorption is increased by

D. i.e. (1, 25 Dihydrocholecalciferol) (477- Ganong 22nd) (371-72- K-Sembulingam 4th)1, 25 Dihvdroxvcholecalciferol - is a steroid hormone synthesized from vitamin D by means of series of hydroxylation reactions in liver and kidneys* Main action is to increase the blood calcium level by increasing the calcium absorption from the small intestine*** Growth hormone - Increases the blod calcium level by increasing the intestinal calcium absorption *** Parathormone - main function is to increase the blood calcium level by mobilizing calcium from bone (resorption)* Calcium and glucocorticoids - decreases blood calcium by inhibiting intestinal absorption.Factors affecting calcium absorption from GITIncreased byDecreased by1. Acidity in the stomach2. Bile and bile salts - increase the solubility of Ca- salts3. Presence of phosphate in adequate amounts in the diets4. Hypo calcemia - seen during pregnancy and lactation: following low Ca intake5. Vitamin D3 - 1, 25 Dihydroxycholecalci- ferol (1,25 DHCC)6. Parathormone (PTH)7. Growth hormone (GH)8. High protein diet1. Presence of alkalies which form insoluble Ca soaps2. Reduce secretion of bile and bile salts - this leads to excess of unabsorbed fatty acids in the GIT which forms insoluble Ca soaps3. Excess of inorganic phosphates, oxalate or phytic acid - converts Ca++ into insoluble form4. Hypercalcemia - seen following high Ca intake which decreases the Ca absorption from the GIT by inhibiting 1.25 DHCC (910 - A,K. Jain 3rd)


Question: Ventricular muscle receives impulses directly from the


Question: Vagal stimulation of the heart causes

(B) (Increased R-R interval in ECG) (113-Gugton 11th)* Vagus is the parasympathetic supply to the heart its stimulation causes- Decreased heart rate- Decreased force of heart contraction- Decreased cardiac output* R-R Interval is the time interval between consecutive heart beat in the electrocardiogram.So a decrease in heart rate increase the R-R interval* Reverse affects on the heart are noted due to sympathetic stimulation (Noradranaline)* During exercise the diastole is shortened more than systole **Control of Heart by the sympathetic (Noradrenaline) and parasympathetic (vagus) nervesParameterParasympathetic (ACH) StimulationSympathetic (ADR)StimulationForce of cardiac contraction (inotropic effect)Decreased (mainly atria little effect on ventricle)IncreasedConductivityDecreasedEnhancedRate of cardiac contractionDecreased (Bradycardia)Increased (Tachycardia)Vagal (parasympathetic) fibers arc distributed mainly to the atria and not much to the ventricles. Thus the major effect of vagal stimulation is to decreased the heart rate or rate of cardiac contraction (bradycardia) Negative inotropic effect of vagal stimulation is less pronouncedSympathetic fibres are distributed to both the atria and the ventricles. Thus sympathetic stimulation has a strong effect on both the heart rate and the force of cardiac contraction* Complete denervation of heart rate will cause an increase in the resting heart rate.Effect of Denervation of the heart (Ganong; Chaudhuri)* The normal heart rate at rest in young persons is about 70/minute (Range between 50-100/min)* The sinuatrial node (SAN) is the normal pacemaker of the heart and generates a rhythm of about 100/minute* The normal heart rate of about 70.min in a young adult is maintained as a result of autonomic influences on the SAM* When both vagal & sympathetic nerves are removed (denervated heart), the sinuatrial node becomes free from all autonomic (sympathetic & parasympathetic) influences and starts generating its normal rhythm of about 100/min* As the normal resting heart rate is usually less, about 70/min, complete denervation of the heart would cause an increases in the heart rate from 70/min to 100/minNodeIntrinsic Rhythm citySinuatrial node (SAN)Atrio ventricular nodeHis - purkinje system100/min50/min30-40/minDuring exercise the diastole is shortened more then svstole.Changes in Duration of systole and Diastole, when heart rate is increased (Exercise)* Exercise is associated with an increase in the heart rate.* Cardiac muscle has the unique property of contracting and repolarizing faster when the heart rate is high* This leads to a decrease in duration of both systole and diastole'"However the duration of systole is much more fixed than that of diastolic and when the heart rate is increased (eg. Exercise) diastole is shortened to a much greater degree" - Ganong* This longer duration of diastole enables;Superior coronary blood flow to the cardiac musculature Q superior ventricular filling Q


Question: The fibers from contralateral nasal retina project to the following layers of lateral geniculate nucleus

On each side, layers 1,4 and 6 of the lateral geniculate nucleus receive input from the contralateral eye, whereas layers 2,3 and 5 receive input from the ipsilateral eye. Illustration showing ganglion cell projections from retina to lateral geniculate nucleus Ref: Ganong&;s review of Medical Physiology 26th edition Pgno: 198


Question: Surfactant secreted by

Surfactant is produced by type II alveolar epithelial cells. Typical lamellar bodies, membrane-bound organelles containing whorls of phospholipid, are formed in these cells and secreted into the alveolar lumen by exocytosis. Tubes of lipid called tubular myelin form from the extruded bodies, and the tubular myelin, in turn, forms the phospholipid film. Following secretion, the phospholipids of surfactant line up in the alveoli with their hydrophobic fatty acid tails facing the alveolar lumen. Surface tension is inversely propoional to their concentration per unit area. The surfactant molecules move fuher apa as the alveoli enlarge during inspiration, and surface tension increases, whereas it decreases when they move closer together during expiration. Some of the protein-lipid complexes in surfactant are taken up by endocytosis in type II alveolar cells and recycled.Ref: Ganong review of medical physiology 23rd edition Page no: 597


Question: On increasing vagal tone following occurs in pacemaker

When the cholinergic vagal fibers to nodal tissue are stimulated, the membrane becomes hyperpolarizedThe slope of the prepotentials is decreased because the acetylcholine released at the nerve endings increases the K+ conductance of nodal tissue.Which cause rapid efflux of K+Ref: Ganong's Review of Medical Physiology Twenty-Third Edition Page No: 491


Question: Phospholipase C acts as secondary messenger for

Phospholipase C is an enzyme which produces inositol tri phosphate and diacylglycerol They causes release of calcium ions which act as secondary messager Epinephrine, norepinephrine, angiotensin, ADH,TRH also require calcium as secondary messager Ref:Guyton and Hall textbook of medical physiology 12th edition,page number:540 to 545


Question: Reward centre is

Punishment centre in brain is posterior hypothalamus and dorsal mid brain.
Rewards centre is ventromedial nuclei of hypothalamus or medial forebrain bundle.


Question: BMR depends on

BMR is defined as the minimal amount of energy required to sustain the body&;s vital functions in the waking state.The most commonly used formula for calculating BMR is that of Harris and Benedict:BMR, Male= 66 + (13.7 x Wt) + (5 x Ht) - (6.8 x age)BMR, Female: 655 + (9.6 x Wt) + (1.8 x Ht) - (4.7 x age)Ref: Ganong&;s review of medical physiology;24th edition; page no-489


Question: Membrane fluidity is exclusively increased by

As the concentration of unsaturated fatty acids in the membrane is increased, fluidity increases. Among the options given, Linoleic acid is the only unsaturated fatty acid and the rest of then are saturated. According to the fluid mosaic model proposed by Singer and Nicolson, the cell membrane is like a sea of phospholipid bilayer with proteins floating in it like icebergs. This fluidity of the membrane is dependent largely on the lipid content of the membrane. The hydrophobic side chains of fatty acids can be aligned to provide a stiff structure to the membrane. As the temperature increases, these side chain transition from a ordered to a disordered fluid like state . The temperature at which this transition occurs from ordered to disordered state is called transition temperature(Tm). Higher the Tm, lower the fluidity of the membrane Longer and saturated fatty acids decrease the fluidity because their side chains interact more strongly with each other. conversely, unsaturated fatty acids increase the fluidity at lower Tm by decreasing the compactness of the side chains . Ref: Harper's illustrated Biochemistry 30th edition pgno: 483-484


Question: The reflex originating from Golgi tendon organ to relax the responding muscle is a

(B) Disynaptic reflex # Golgi tendon organ> The receptor for the inverse stretch reflex is in the Golgi tendon organ.> There are 3-25 muscle fibers per tendon organ.> They are stimulated by both passive stretch and active contraction of the muscle.> The threshold of the Golgi tendon organs is low.

Reflex centre of which is situated in medulla oblongata


Question: Energy currency of the cell is

Cellular energy can be stored in high-energy phosphate compounds, including adenosine triphosphate (ATP). This ubiquitous molecule is the energy storehouse of the body. On hydrolysis to adenosine diphosphate (ADP), it liberates energy directly to such processes as muscle contraction, active transpo, and the synthesis of many chemical compounds. Loss of another phosphate to form adenosine monophosphate (AMP) releases more energy.(REF: GANONG'S REVIEW OF MEDICAL PHYSIOLOGY -23rd EDITION. Page No-8)


Question: Defect in Orexin production is seen in

In Narcolepsy there is defect in Orexin production


Question: Function of Basement membrane is

(Filtration) (10- Ganong 22nd) (103- Robbins 7th) (34- Ganong 23rd)Basement membrane - (Basal lamina) are produced by epithelial and mesenchymal cells and are closely associated with the cell surface. They consist of a network of amorphous nonfibrillar collagen (Mostly type IV) laminin heparan sulfate, proteoglycan, fibronectins, tenascinRole of extracellular Matrix (Interstitial matrix, Basement membrane)1. Mechanical support of cell anchorage and cell migration and maintenance of cell polarity2. Control of cell growth - cell proliferation3. Maintenance of cell differentiation4. Scaffolding for tissue renewal5. Establishment of tissue microenvironments6. Storage and presentation of regulatory molecules eg. growth factor like FGF and HGF* The major function of Glomerulus basement membrane is filtration


Question: Isovolumetric relaxation phase of the cardiac cycle ends with


Question: The normal plasma osmolality (mOsmol/kg) is

Normal human reference range of osmolality in plasma is about 285-295 milli-osmoles per kilogram.Ref: Ganong&;s review of medical physiology; 24th edition; page no; 310


Question: Type of blood flow seen in the apex of the lung is

Zone 2: Intermittent blood flow only during the peaks of pulmonary aerial pressure (Ppc) because the systolic pressure is then greater than the alveolar air pressure (PALV), but the diastolic pressure is less than the alveolar air pressure.

Intermittent flow, P(ALV) < Ppc during diastole

Intermittent flow, P(ALV) < Ppc during systole


Question: Treatment of lepra reaction with acute neuritis is

Prednisolone is the drug of choice for treatment of lepra reaction with acute neuritis.


Question: The following is related to hyperinflation of the lung

J -reflex is produced due to hyper inflation of the lung It produces: Apnoea followed by rapid shallow breathing, hypotension, bradycardia Ref:Guyton and Hall textbook of medical physiology 12th edition, page number:373


Question: GH secretion is

Peptide hormones. ... Sex hormones. ... Clonidine and L-DOPA by stimulating GHRH release. a4b2 nicotinic agonists, including nicotine, which also act synergistically with clonidine. Hypoglycemia, arginine and propranolol by inhibiting somatostatin release. Deep sleep. Insulin. Ref: guyton and hall textbook of medical physiology 12 edition page number: 550,551,552

Stimulates B-cells of pancreases directly


Question: Normal capillary wedge pressure

Ans. (b) 5-10mmHgRef: Ganong, 25th ed/p.574Mean Pulmonary capillary wedge pressure (PCWP)=9mmHg (Range - 4 to 12 mm Hg)PCWP is usually measured using a balloon-tipped, multilumen catheter called Swan-Ganz catheter


Question: Stereoanesthesia is due to lesion ofa) Nucleus Gracilisb) Nucleus cuneatusc) Cerebral cortexd) Spinothalamic tract

Astereognosis/Stereoanaesthesia- Loss of ability to recognize size and shape of an object.
Seen in- lesion of somatosensory cortex, lesion of tractus cuneatus, lesion of tractus gracilis.
Somatosensory cortex lesion- proprioception and tactile sensations are lost while pain and temperature sensations are preserved.
Tractus cuneatus- formed by fasciculus cuneatus (spinal cord) and nucleus cuneatus (medulla). Pass through lateral portion of dorsal column. Carries sensations of dorsal column- proprioception and tactile sensations from upper part of the body.
Tractus gracilis- formed by fasciculus gracilis (spinal cord) and nucleus gracilis (medulla). Pass through medial portion of dorsal column. Carries sensations of dorsal column- proprioception and tactile sensations from lower part of the body.


Question: Peripheral vascular resistance is best given by

Mean arterial pressure responsible for blood flow to organ

Diastolic blood pressure as it decreases till mid-thoracic aorta

Pulse pressure as it relates to stroke volume and aortic compliance

Systolic pressure as it increase in descending aorta


Question: Least conduction velocity is seen in


Question: Methoctramine is a


Question: Aromatase enzyme

Aromatase enzyme conves androgens to estrogens.5a-Reductase conves testosterone to dihydrotestosteroneAromatase inhibitors block the function of the aromatase enzyme that conves androgens to estrogens. Aromatase inhibitors, including letrozole, anastrozole, and exemestane, are highly effective for both adjuvant and metastatic treatment of breast cancer in postmenopausal subjects,5a-Reductase inhibitors like finasteride, dutasteride are used in BPHG&G 12e 1953

Helps in maintaining normal placental blood flow

Conves testosterone to dihydrotestosterone


Question: Arterial PO2 is decreased in hypoxia due to

COPD presents with Hypoxic Hypoxia. Hypoxic hypoxia is the most common form of hypoxia seen clinically.
The diseases that cause it can be roughly divided into those in which the gas exchange apparatus fails, those such as congenital heart disease in which large amounts of blood are shunted from the venous to the arterial side of the circulation, and those in which the respiratory pump fails.
Lung failure occurs when conditions such as pulmonary fibrosis produce alveolar-capillary block, or there is ventilation-perfusion imbalance.
Pump failure can be due to fatigue of the respiratory muscles in conditions in which the work of breathing is increased or to a variety of mechanical defects such as pneumothorax or bronchial obstruction that limit ventilation.
It can also be caused by abnormalities of the neural mechanisms that control ventilation, such as depression of the respiratory neurons in the medulla by morphine and other drugs.


Question: Hyperventilation in high altitude is due to

Hyperventilation in high altitude is due to respiratory alkalosis Ref: guyton and hall textbook of medical physiology 12 edition page number:375,376,377


Question: Functions of basal ganglia


Question: Macula densa is present in

The thick end of the ascending limb of the loop of Henle reaches the glomerulus of the nephron from which the tubule arose and nestles between its afferent and efferent aerioles. Specialized cells at the end form the macula densa, which is close to the afferent and paicularly the afferent aeriole. The macula, the neighboring lacis cells, and the renin-secreting juxtaglomerular cells in the afferent aeriole from the juxtaglomerular apparatus. Ref: Ganong&;s review of medical physiology,23rd edition, page no: 641


Question: Neutral substances are transported across the cell membrane by

Neutral substances cross membranes based on their concentration gradient. That occurs by diffusion.


Question: According to myogenic hypothesis of renal autoregulation, the afferent aerioles contract in response to stretch induced by

Most vascular beds have an intrinsic capacity to compensate for moderate changes in perfusion pressure by changes in vascular resistance, so that blood flow remains relatively constant. This capacity is well developed in the kidneys (), but it has also been observed in the mesentery, skeletal muscle, brain, liver, and myocardium. It is probably due in pa to the intrinsic contractile response of smooth muscle to stretch (myogenic theory of autoregulation). As the pressure rises, the blood vessels are distended and the vascular smooth muscle fibers that surround the vessels contract. If it is postulated that the muscle responds to the tension in the vessel wall, this theory could explain the greater degree of contraction at higher pressures; the wall tension is propoional to the distending pressure times the radius of the vessel (law of Laplace; see Chapter 32), and the maintenance of a given wall tension as the pressure rises would require a decrease in radius. Ref: Ganong&;s review of medical physiology,23rd edition, page: 563


Question: Bilirubin secretion is stimulated by

Bile salts are the most important cholerectic or the substance that increases bile secretion. Cholecystokinin (CCK) is the most important cholagogue or substance that increases gallbladder contraction.


Question: Volume of ICF in body

In a 70 kg man 60 % of body weight is due to water Of that water 2/3 rd is present intra cellularly Ref:Guyton and Hall textbook of medical physiology 12th edition,page number: 45,46,47


Question: Structure without any membrane is

Nucleolus is present in nucleus. Theirfunction is to produce ribosome. They are not enclosed by a membrane and contain proteins, DNA, RNA. (REF TEXTBOOK OF MEDICAL PHYSIOLOGY GEETHA N 2 EDITION, PAGE NO - 11)


Question: Orthopnea is heart failure develops due to

When a normal individual lies down, the pulmonary blood volume increases by up to 400 mL
When the person stands up this blood is discharged into the general circulation.
This shift is the cause of the decrease in vital capacity in the supine position and is responsible for the occurrence of orthopnea in heart failure.

Reservoir function of pulmonary arteries


Question: Cyanosis is not seen in

Cyanosis is a bluish discoloration of the skin and mucous membranes resulting from inadequate oxygenation of the blood and not seen in CO poisoningRef: Hutchison&;s Clinical Methods, 23ed edition, page no: 21


Question: Nerve fibres innervating sweat glands release the following at their ending

Nerve fibres innervating sweat glands are cholinergic.Ref: Ganong&;s review of medical physiology 23rd edition Page no: 267


Question: Functional residual capacity is

Functional Residual Capacity (FRC) is expiratory reserve volume + residual volume. From the picture givERV+RV) Lung Capacities The total lung capacity can be broken down into alternate capacities that help to define functioning lings. The vital capacity refers to the maximum amount of air expired from the fully inflated lung or maximum inspiratory level. The inspiratory capacity is the maximum amount of air inspired from the end-expiratory level. The functional residual capacity represents the volume of the air remaining in the lungs after expiration of a normal breath. REf: Ganong&;s Review of Medical Physiology 25th edition PGno: 628, 629


Question: Gatekeeper of the heart is

Ans. (b) AV node(Ref: Ganong, 25th ed/p.521)AV node conduction is slow. There is a delay of about 0.1 s in spread of impulseThis delay is mainly responsible for the sequential contraction of atrium followed by ventricles. It is for this reason, AV node is also called "Gatekeeper" to the ventricles


Question: Hormone synthesized as peptide precursor is/are

Insulin- A polypeptide hormone secreted by the islets of Langerhans and functioning in the regulation of the metabolism of carbohydrates and fats, especially the conversion of glucose to glycogen, which lowers the blood glucose level.Ref: Ganong&;s review of medical physiology; 24th edition; page no: 431


Question: Cerebral blood flow is depend on

i.e. (CO2 concentration): (441- Lee's) (376-77-AK-Jain 4th/anaesthesia 12th)Cerebral blood flow increases in linearity with rise in arterial PC02 (Direct effect)Cerebral blood flow (CBF) is the difference between mean arterial pressure and intracranial pressure or central venous pressure which ever is higher.It is 50 mi/100 gm of brain tissueSince ions are not able to cross the blood brain barrier as easily as O2, O2 and lipid soluble substances (such as most anaesthetics) the ions have little effects on cerebral blood flowFactors affecting cerebral blood flow (CBF)A. Cerebral metabolism - cerebral blood flow varies directly with metabolic activity, various studies have shown that regional CBF parallels metabolic activity for eg motor activity of a limb is associated with an increased in regional CBF of the corresponding motor cortex. Similarily, visual activity is associated with an increase in regional CBF of the corresponding occipital cortex.B. Cerebral Perfusion pressure: is the difference between mean arterial pressure (MAP) and intracranial pressure (ICP) or central venous pressure (CVP) which ever is greater CPP is normally 80-100 mm Hg. Because ICP is normally less than 10 mm Hg. CPP is primarily dependent on MAP. Autoregulation maintains a steady CBF as perfusion pressure varies between 60 and 160 mm Hg. Decrease in CPP results in cerebral vasodilation, where as elevations induce vasoconstriction.C. Arterial PCO2 - The most important extrinsic influences on CBF are respiratory gas tensions particularly arterial PCO2. CBF is directly proportional to arterial PCO2 between tensions of 20 and 80 mm of Hg. The effect is almost immediates and is thought to be secondary to changes in the PH of CSF and cerebral tissueD. Arterial PO2: only marked changes in arterial PO2 alter CBF whereas hypoxia may be associated with only minimal decrease (-10%) in CBF severe hypoxemia (arterial PO2 less than 50 mm Hg) profoundly increases CBFE. Temperature - CBF changes 5 - 7% 1degC change in temperature. Hypothermia decreases both cerebral metabolic rate and CBF. Whereas pyrexia has the reverse effect.F. Blood viscosity - CBF rises as viscosity falls and vise versaG. Autonomic system* Cerebral blood flow is maintained at constant levels (does not change) in response to moderate exercise)**** Mild to moderate decrease in perfusion pressure decreases driving forces for flow, resulting in CO2 accumulation, which by release of H+ produces cerebral vasodilation.* Most important factor for regulating cerebral blood flow under normal conditions is the rate of cerebral CO2formation.


Question: Inward flow of Na+ in hea leads to

Entry of Na ions into cardiac cell leads to depolarisation. (REF TEXTBOOK OF MEDICAL PHYSIOLOGY GEETHA N 2 EDITION, PAGE NO 52)


Question: Commonest cause of death in peptic ulcer patients is

Peptic ulcers may be in thestomach, the small intestine just below the stomach, or the food pipe above the stomach. Sometimes,peptic ulcers can bleed (known asbleeding ulcers). More severebleeding, known as hemorrhaging, can be life-threatening. Ref surgery Srb 5e p432


Question: "Inflation of lungs induces fuher inflation" this is explained by

Head's paradoxical reflex is paradoxical to Hering- Breuer inflation reflex This reflex might be the cause for inflation of the lungs in the newborn when the newborn takes the first breath


Question: In dark adaptation, there occurs

Dark adaptation The physical and chemical adjustments of the eye, including dilation of the pupil and increased activity of rods in the retina, that make vision possible in relative darkness.Ref: Ganong&;s review of medical physiology, 23rd edition Page no: 171


Question: Kidney producesa) Vasopressinb)  Erythropoietinc) Renind) Angiotensinogene) 25 hydroxy vit D

Hormones secreted by Kidney

Renin
Erythropoietin
1,25 DHCC


Question: Loss of dorsal column result in loss of

The dorsal column-medial lemniscus pathway (DCML) (also known as the posterior column-medial lemniscus pathway (PCML)) is a sensory pathway of the central nervous system that conveys sensations of fine touch, vibration, two-point discrimination, and proprioception (position) from the skin and joints. Ref: guyton and hall textbook of medical physiology 12 edition page number:691,692,693


Question: Nerve fibres carrying fast pain is

Fast pain is carried by Aδ fibres
Slow pain is carried by C fibres


Question: The white matter of cerebellum is well myelinated at

The white matter of cerebellum is well myelinated at 1 month.Ref: Ganong&;s review of medical physiology, 23rd edition, Page no:254


Question: The gastric phase of gastric secretion is brought about by


Question: Sodium channel is

Ans. (c) HeterotrimericNa K pump has 2 subunits and both the subunits are different. That's why it is called as a heterodimerIt can contain one alpha, one beta and one gamma subunit also - so, heterotrimeric


Question: Hypoxia causes vasoconstriction in

"O2 deficiency (Hypoxia), Accumulation of CO2,| PH produce vasoconstriction in the lungs. While these in the other tissues produce vasodilatation.Ref: Guyton; 13th edition


Question: Vomiting centre receives stimulus from

Vomiting centre in medulla receives stimulus from-
-        Chemoreceptor trigger zone- Area postrema
-        Vestibular system
-        Periphery- eg: irritation of gut, MI, biliary stones, renal stones
-        Cortical centres


Question: Decreases contributory factor in chronic hypertension is associated with

[Cl (Nitric oxide) (598- Ganong 22th) (560- 562- K.S.4th) (336-A.K. Jain 3rd) (564- Ganong 23rd)* Excess of secretion of aldosterone from adrenal cortex leads to hypertension* Tumours of the Juxtaglomerular cells leading to formation of excess of angiotension II- leads to Renal hypertension* Nitric oxide (No) is an endothelium derived relaxing factor. It is synthesized from arginine. It is a vasodilator deficiency of this leads to hypertension* Nitric oxide is necessary for maintenance of normal blood pressure (NO- deficiency is associated with hypertension)


Question: The primary direct stimulus for excitation of central chemoreceptors is

The central chemoreceptors monitor the H+ concentration of cerebrospinal fluid (CSF), including the brain interstitial fluid.CO2 readily penetrates membranes, including the blood-brain barrier, whereas H+ and HCO3- penetrate slowly. The CO2 that enters the brain and CSF is promptly hydrated. The H2CO3 dissociates so that the local H+ concentration rises. The H+ concentration in brain interstitial fluid parallels the aerial PCO2. Experimentally produced changes in the PCO2 of CSF have minor, variable effects on respiration as long as the H+ concentration is held constant, but any increase in spinal fluid H+ concentration stimulates chemoreceptorsRef: Ganong's Review of Medical Physiology Twenty-Third Edition, Page No: 629


Question: Conscious proprioception is transmitted via

(A) Dorsal column > Proprioceptive information is transmitted up the spinal cord in the dorsal column.> Majority of the proprioceptive input goes to the cerebellum but some passes to the cortex also (conscious proprioception). Conscious picture of the body in space is synthesized in the cortex.> There is some evidence that proprioceptive information passes to consciousness in the anterolateral column, also however this in all likelihood will be less important than the dorsal column.> Remember:> Dorsal column transmits:> Touch (fine)> Pressure> Vibration> Joint position sense> Lateral spinothalamic tract transmits:> Pain> Temperature> Anterior spinothalamic tract transmits:> Crude touch, Pressure


Question: Factor X is

Factor X is also called as Stua-Prower factor Ref: Ganong 25th ed/page 566


Question: Androgen is secreted by

Any steroid hormone that promotes male secondary sex characters. The two main androgens are androsterone and testosterone. The androgenic hormones are internal endocrine secretions circulating in the bloodstream and manufactured mainly by the testes under stimulation from the pituitary gland.Ref: Ganong&;s review of medical physiology; 24th edition; page no:-428


Question: Highest frequency among the following waves of EEG is seen in


Question: Normal FSh levels in adult male is

Before pubey - 0 to 4.0 mIU/mL (0 to 4.0 IU/L) During pubey - 0.3 to 10.0 mIU/mL (0.3 to 10.0 IU/L) Women who are still menstruating - 4.7 to 21.5 mIU/mL (4.5 to 21.5 IU/L) After menopause - 25.8 to 134.8 mIU/mL (25.8 to 134.8) Ref: guyton and hall textbook of medical physiology 12 edition page number:636,637,638


Question: Cyanosis in trauma is interpreted as

Cyanosis is a bluish discoloration of the skin, mucous membranes, tongue, lips, or nail beds and is due to an increased concentration of reduced hemoglobin (Hb) in the circulation. Clinically evident cyanosis typically occurs at an oxygen saturation of 85% or less. Mild cyanosis may be difficult to detect Ref: guyton and hall textbook of medical physiology 12 edition

Absence of cyanosis means adequate tissue ventilation

Absence of cyanosis means adequate tissue oxygenation


Question: Maximum reservoir of blood

At rest, at least 50% of the circulating blood volume is in the systemic veins, 12% is in the hea cavities, and 18% is in the low-pressure pulmonary circulation. Only 2% is in the aoa, 8% in the aeries, 1% in the aerioles, and 5% in the capillaries Ref: Ganong's Review of Medical Physiology Twenty-Third Edition Page No:543


Question: Highest concentration of potassium is seen in

K+ channels are present in the luminal as well as the basolateral membrane of the enterocytes of the colon, so K+ is secreted into the colon. In addition, K+ moves passively down its electrochemical gradient. The accumulation of K+ in the colon is paially offset by H+-K+ ATPase in the luminal membrane of cells in the distal colon, with resulting active transpo of K+ into the cells. Neveheless, loss of ileal or colonic fluids in chronic diarrhea can lead to severe hypokalemia. When the dietary intake of K+ is high for a prolonged period, aldosterone secretion is increased and more K+ enters the colon. This is due in pa to the appearance of more Na+- K+ ATPase pumps in the basolateral membranes of the cells, with a consequent increase in intracellular K+ and K+ diffusion across the luminal membranes of the cells. The intestines are presented each day with about 2000 mL of ingested fluid plus 7000 mL of secretions from the mucosa of the gastrointestinal tract and associated glands. Ninety-eight percent of this fluid is reabsorbed, with a daily fluid loss of only 200 mL in the stools. In the small intestine, secondary active transpo of Na+ is impoant in bringing about absorption of glucose, some amino acids, and other substances such as bile acids (see above). Conversely, the presence of glucose in the intestinal lumen facilitates the reabsorption of Na+. In the period between meals, when nutrients are not present, sodium and chloride are absorbed together from the lumen by the coupled activity of a sodium/hydrogen exchanger (NHE) and chloride/bicarbonate exchanger in the apical membrane, in a so-called electroneutral mechanism. Water then follows to maintain an osmotic balance. In the colon, moreover, an additional electrogenic mechanism for sodium absorption is expressed, paicularly in the distal colon. In this mechanism, sodium enters across the apical membrane an ENaC (epithelial sodium) channel that is identical to that expressed in the distal tubule of the kidney. This underpins the ability of the colon to desiccate the stool and ensure that only a small poion of the fluid load used daily in the digestion and absorption of meals is lost from the body. Following a low-salt diet, increased expression of ENaC in response to aldosterone increases the ability to reclaim sodium from the stool. The pancreatic juice is alkaline and has a high HCO3 content (approximately 113 mEq/L vs. 24 mEq/L in plasma). About 1500 mL of pancreatic juice is secreted per day. Bile and intestinal juices are also neutral or alkaline, and these three secretions neutralize the gastric acid, raising the pH of the duodenal contents to 6.0 to 7.0. By the time the chyme reaches the jejunum, its pH is nearly neutral, but the intestinal contents are rarely alkaline. Bile is made up of the bile acids, bile pigments, and other substances dissolved in an alkaline electrolyte solution that resembles pancreatic juice.REF: GANONG&;S REVIEW OF MEDICAL PHYSIOLOGY, KIM BARRETT, HEDDWEN BROOKS, SCOTT BOITANO, SUSAN BARMANTWENTY THIRD EDITIONPAGE NO:435,438,441,442


Question: Compliance of lung is measured by

The extent to which the lungs will expand for each unit increase in transpulmonary pressure is called the lung compliance.
The total compliance of both lungs together in the normal adult human being averages about 200 milliliters of air per centimeter of w ater transpulmonary pressure.
That is, every time the transpulmonary' pressure increases 1 centimeter of water, the lung volume, after 10 to 20 seconds, will expand 200 milliliters.
The characteristics of the compliance diagram are determined by the elastic forces of the lungs.
These can be divided into twro parts:

(I) elastic forces of the lung tissue and
(2) elastic forces caused by surface tension of the fluid that lines the inside walls of the alveoli and other lung air spaces,

The elastic forces of the lung tissue are determined mainly by elastin and collagen fibers


Question: Mechanism of analgesia is by

The degree to which a person reacts to pain varies tremendously. This variation results paly from a capability of the brain itself to suppress input of pain signals to thenervous system by activating a pain control system called an analgesia system. The analgesia system consists of three major components: (1) The periaqueductal gray and periventricular areas of the mesencephalon and upper pons surround the aqueduct of Sylvius and poions of the third and fouh ventricles. Neurons from these areas send signals to (2) the raphe magnus nucleus, a thin midline nucleus located in the lower pons and upper medulla, and the nucleus reticularis paragigantocellularis, located laterally in the medulla. From these nuclei, second-order signals are transmitted down the dorsolateral columns in the spinal cord to (3) a pain inhibitory complex located in the dorsal horns of the spinal cord. At this point, the analgesia signals can block the pain before it is relayed to the brain. Ref: guyton and hall textbook of medical physiology 12 edition page number:698,699,700


Question: Source of EEG

(C) EPSP and IPSP of cortical cells which behave like dipoles > The dendrites of the cortical cells are a forest of similarly oriented, densely packed units in the superficial layers of the cerebral cortex.> Propagated potentials can be generated in dendrites. In addition, recurrent axon collaterals end on dendrites in the superficial layers.> As excitatory and inhibitory endings on the dendrites of each cell become active, current flows into and out of these current sinks and sources from the rest of the


Question: Most potent stimulus for secretin secretion is

Protein / acid in duodenum is the most potent stimulus for secretion of secretin.


Question: Maximum contribution of plasma osmolarity is by

Sodium is the major contributor plasma osmolarity Ref: guyton and hall textbook of medical physiology 12 edition page number: 50,51,52


Question: Velocity of conduction for A alpha fibers is


Question: Bone removing cells

An osteoclast is a type of bone cell that breaks down bone tissue. This function is critical in the maintenance, repair, and remodeling of bones of the veebral skeleton. The osteoclast disassembles and digests the composite of hydrated protein and mineral at a molecular level by secreting acid and a collagenase, a process known as bone resorption. This process also helps regulate the level of blood calcium.Ref: Ganong&;s review of medical physiology; 24th edition; page no:-386


Question: A single cell within a culture of freshly isolated cardiac muscle cells is injected with a fluorescent dye that cannot cross cell membranes. Within minutes, several adjacent cells became fluorescent. The most likely explanation for this observation is the presence of

Gap junctions are pores composed of paired connexons that allow the passage of ions, nucleotides, and other small molecules between cells.Ref: Guyton; 13th edition


Question: Aerial PO2 is decreased in hypoxia due to

COPD presents with Hypoxic Hypoxia. Hypoxic hypoxia is the most common form of hypoxia seen clinically. The diseases that cause it can be roughly divided into those in which the gas exchange apparatus fails, those such as congenital hea disease in which large amounts of blood are shunted from the venous to the aerial side of the circulation, and those in which the respiratory pump fails. Lung failure occurs when conditions such as pulmonary fibrosis produce alveolar-capillary block, or there is ventilation-perfusion imbalance. Pump failure can be due to fatigue of the respiratory muscles in conditions in which the work of breathing is increased or to a variety of mechanical defects such as pneumothorax or bronchial obstruction that limit ventilation. It can also be caused by abnormalities of the neural mechanisms that control ventilation, such as depression of the respiratory neurons in the medulla by morphine and other drugs.Ref: Ganong review of medical physiology 23rd edition Page no: 620


Question: Lifespan of neutrophils is

The average half-life of a neutrophil in the circulation is 6 hoursRef: Ganong's Review of Medical Physiology Twenty-Third Edition Page No: 64


Question: The haemoglobin derivative that is formed due to reaction of CO2 with blood is

Reduced hemoglobin: It results from release of O2 from oxyHb. Carbaminohemoglobin:In this, CO2 is attached to the globin pa of Hb. The affinity of Hb for CO2 is about 20 times that for oxygen. Carboxyhemoglobin: Carbon monoxide is attached to Hb where O2 is normally attached. The affinity of Hb for CO is 200-300 times that for O2. It is normally present in small amounts, but in large amount in smokers in whom it impairs O2 transpo. Methemoglobin: When blood is exposed to some drugs, or oxidising agents in vitro or in vivo, the ferrous iron of Hb is conveed into ferric iron, forming metHb, which is dark in color. When present in large amounts, it gives a dusky appearance to the skin. Small amounts of metHb are formed normally but an enzyme system conves it back to Hb.


Question: Oxygen consumption of myocardium is

The basal O2 consumption by the myocardium is about 2 mL/ 100 g/min that is 20mL/kg/minRef: Ganong's Review of Medical Physiology Twenty-Third Edition Page No:519


Question: Bradycardia in athletes is due to

(A) (increased vagal tone)Persons undergoing long term training develop bradycardia at rest. The resting pulse rates in some top class sportsmen/ atheletes (for example. Zatopek. Borg) are quite low. This bradycardia is believed to be due to excessive tone of the vagi. On the other hand, exercise of some intensity will cause less rise of pulse rate after trainingAthletic pseudonephritis ; prolonged, heavy exercise, increases proteins, cells and other abnormal substance in urine due to1. Decrease in renal blood flow (RBE) produces glomerular capillary hypoxia, and increases permeability to large molecules2. Increase in plasma proteins during exercise3. Decreased rate of RBF, thus larger time is required to filter these moleculerCauses of BradycardiaPhysiologicalPathologicalDrugs* Sleep* Athletes* Hypothermia* Hypothyroidism* Heart attack* CHD* Degenerative process of aging* Obstructive jaundice* Increased intracranial pressure* Beta blockers* Channel blocker* Digitalis and antiarrhythmic drugs.


Question: RMP of smooth muscle is

Average RMP value is approx -50mV. (Ref: Textbook of physiology AK Jain 5th edition page no.188)


Question: Parietal cell secretes

Parietal cells located deep in the oxyntic glands secrete HCl & intrinsic factor. -Mucus is secreted by mucous neck cells of oxyntic glands. Pepsinogen is secreted by chief/peptic cells of oxyntic glands. -G cells of pyloric glands release hormone gastrin. Reference: Guyton,11e


Question: In comparison to the apex of the lung, the base of the lung has

Apical alveoli have low ventilation and perfusion per unit volume of the lung, whereas the basal alveoli have high ventilation and perfusion.
Ventilation-perfusion ratio and the PaO2 is maximum at the apex. PCO2 is maximum at the base.


Question: Decrease reflex response after repetitive stimulation

Fatigue is produced in pa by bombardment of the brain by neural impulses from muscles and the decline in blood ph produced by lactic acidosis also makes one feel tired. Ref: Ganong&;s review of medical physiology;23rd edition; pg:637.


Question: In NREM stage 4, the EEG waves are

(A) 5 # There are two different kinds of sleep: rapid eye movement (REM) sleep and non-REM (NREM), or slow-wave sleep.> NREM sleep is divided into four stages. A person falling asleep first enters Stage 1, which is characterized by low-amplitude, high-frequency EEG activity. Stage 2 is marked by the appearance of sleep spindles. These are bursts of alpha-like, 10-14 Hz, 50 uV waves. In stage 3, the pattern is one of lower frequency and increased amplitude of the EEG waves. Maximum slowing with large waves is seen in Stage 4. Thus, the characteristic of deep sleep is a pattern of rhythmic slow waves, indicating marked synchronization.


Question: Most afferent fibers from the lateral nucleus terminate in the primary visual cortex is

Like almost all other portions of the visual cortex, the primary visual cortex has six distinct layers. Also, as is true for the other sensory systems, the geniculocalcarine fibres terminate mainly in layer 4.


Question: A 25 year old man has muscle blood flow of 500ml/min. He has mean arterial pressure of 160mmHg and mean venous pressure of 10mmHg of muscle. Calculate vascular resistance of the muscle of this man.


Question: Largest fraction of CO2 is present in blood as


Question: Blood flow of resting skeletal muscle is

The blood flow of resting skeletal muscle is low (2-4 mL/100 g/ min). Ref: Ganong's Review of Medical Physiology Twenty-Third Edition Page No:518


Question: Atrioventricular nodal delay is due to

Cause of the Slow Conduction. The slow conduction in the transitional, nodal, and penetrating A-V bundle fibers is caused mainly by diminished numbers of gap junctions between successive cells in the conducting pathways, so there is great resistance to conduction of excitatory ions from one conducting fiber to the next. Therefore, it is easy to see why each succeeding cell is slow to be excited.Ref: Guyton and Hall textbook of medical physiology 13th edition. Page:125


Question: Sweating as a result of exertion is mediated through

Sweat glands have a sympathetic but cholinergic nerve supply.


Question: Normal GFR is

Ans. (c) 125 ml/minRef: Ganong's physiology 23rd ed./ 646* Normal GFR in a healthy person is 125ml/min.

Glomerular Filtration, Renal Blood Flow, and Their Control


Question: In hyperventilation

Abnormally fast and deep breathing, the result of either an emotional state or a physiological condition. Emotional causes include acute anxiety and emotional tension, such as in nervous, anxious patients who may have other functional disturbances related to emotional problems. Physiological causes include a rapid decrease in intracranial pressure, other neurologic problems, and metabolic, pulmonary, and cardiovascular conditions.Ref: Ganong&;s Review of Medical Physiology; 24th edition; page no:647


Question: Effectiveness of blood brain barrier is by

The blood-brain barrier is formed by endothelial cells of the capillary wall, astrocyte end-feet ensheathing the capillary, and pericytes embedded in the capillary basement membrane. Ref: guyton and hall textbook of medical physiology 12 edition page number:671,672,673


Question: Vestibulo ocular reflex is concerned with

The flocculonodular lobe is phylogenetically the oldest pa of cerebellum has vestibular connections and is concerned with equilibrium and eye movements (vestibulo ocular reflex). Ref: Ganong&;s review of medical physiology; 23rd edition; pg:257.


Question: After hyperpolarisation phase of the action potential is due to

After hyperpolarisation Phase : Part of action potential below RMP
It is due to slow return of K+ channels to closed


Question: The most important action of Secretin is to

Main Action of Secretin:
Secretin increases the secretion of bicarbonate by the duct cells of the pancreas and biliary tract. It thus causes the secretion of a watery, alkaline pancreatic juice (with high content of bicarbonate). Its action on pancreatic duct cells is mediated via cAMP.
Secretin causes alkaline pancreatic juice to flood into the duodenum, neutralizing the acid from the stomach and thus inhibiting further secretion of the hormone - feedback control.
Other actions:

Inhibits gastric juice secretion.
Inhibits gastric motility.
Causes contraction of pyloric sphincter.
Augments the potency of action of cholecystokinin on pancreatic secretion.

increase secretion of bicarbonates by pancreas


Question: A patient presents with hepatomegaly and hypoglycemia not responding to epinephrine. Most probable diagnosis is


Question: Total alveolar ventilation volume (in L/min) is

Ans. (c) 4.2(Ref: Ganong, 25th ed/p.629)Alveolar ventilation is 4.2L/minAlveolar ventilation = respiratory rate * (tidal volume - dead space) =12(500-150)=4.2L/min


Question: Protein C activation causes

Binding of thrombin with thrombomodulin slow the clotting process by removing thrombin, the thrombomodulin-thrombin complex also activates a plasma protein, protein C, that actssnanticoagulant by inactivating activated Factors V and VIII.Ref: Guyton and Hall textbook of medical physiology 13th edition. Page: 489


Question: Maintainence of BP according to intracranial pressure is

Cushings reflex is a special type of CNS ischemic response. The cause is raised intracranial tension. Mechanism isRaisrd intracranial tensionDecreased blood flow to brain Ischemia of VMCStimulation of VMCVasoconstriction and increase in BPStimulation of baroreceptors Sinoaoic reflex Stimulation of CICRelex bradycardia Ref: Textbook of medical physiology by N Geetha, 2nd edition, page no. 164


Question: HB estimation is not done by

Some methods of hemoglobin estimation are : Drabkin's method Sahli's method Hemoglobincyanide (HiCN) Method Blood Gas Analyzer (BGA) Whereas Wintrobe's method and Westergren's method: for ESR determination.


Question: CO2 increases ventilation by acting mainly on receptors of

In the medulla, the ventral respiratory group (VRG) consists of four groups of neurons that make up the exhalation (expiratory) area of respiratory control. ... The VRG contains both inspiratory and expiratory neurons. In quiet, restful breathing, the ventral respiratory group of neurons are inactive Ref: guyton and hall textbook of medical physiology 12 edition page number: 370,371,372


Question: Fick's law gives the rate of transpo in case of

Fick's law is used to calculate the rate of simple diffusionSimple diffusion means that kinetic movement of molecules or ions occurs through a membrane opening or through intermolecular spaces without any interaction with carrier proteins in the membrane. The rate of diffusion is determined by the amount of substance available, the velocity of kinetic motion, and the number and sizes of openings in the membrane through which the molecules or ions can move.Ref: Guyton; 13th edition; Chapter 4; Transpo of Substances Through Cell Membranes


Question: Increased BP & decreased heart rate is seen in

Raised intracranial pressure initiates Cushing’s reflex. Cushing’s reflex leads to a rise in arterial pressure, which restores the blood supply to the brain. At the same time, the raised BP causes reflex Bradycardia through the baroreceptors.


Question: Broca's area situated in

Broca's motor speech area or area 44and 45 is a special region of premotor coex situated in the inferior frontal gyrus. This area is present, especially in dominated hemisphere (left hemisphere in right-handed person). Broca's area is concerned with the movements of those structures, which are responsible for the production of voice and aiculation of speech. Ref: guyton and hall textbook of medical physiology 12 edition page number:668,669,700


Question: The primary action of Nitric oxide (NO) in the gastrointestinal tract is

In the gastrointestinal tract,NO impoant in the relaxation of smooth muscle NO act as inhibitory neurotransmitter in git. It doesnt have membrane bound receptor and diffuses into target cells and iactivates guanyl cyclase- produces cGMP from GTP- mediates smooty muscles relaxation.

Gastrointestinal smooth muscle relaxation

Gastrointestinal slow smooth muscle contraction


Question: Caudal regression syndrome is seen in babies of mother having


Question: Regarding Glomerular filtration rate (GFR) is

(Inulin clearance measure the GFR) (31 6- 18-Guy ton 11th, 643-4.5-Ganong 23rd, 302-K Sembulingam 5th). In the average adult human the GFR is about 125ml/min, 1.73 smq/cm2 or 180L/day and tubular reabsorption is 178.5 L/day, leaving 1.5L/day of fluid to be excreted in the urineGFR is about 20% of the renal plasma flowGFR = Kt (Glomerular capillary filtration coefficient) x Net filtration pressure* Renal blood flow - Average (70 kg) man the combined blood flow through both kidney is about 1100 ml/min or about 22% of cardiac out put A substance that is completely filtered but neither reabsorbed nor secreted should be used to measure the GFR i.e. - InulinMeasurement of GFR1. Inulin - clearance test - Most commonly used2. Urea - clearance test3. Cr51 - EDTA clearance test4. Endogenous creatinine clearance test (Worth while index of renal functions)**Increased glomerular capillary colloid osmotic pressure decrease GFRTwo factor that influence the glomerular capillary colloid osmotic pressure raises the glomerular capillary colloid osmotic pressure which in turn decreases GFR***1. Arterial plasma colloid osmotic pressure (oncotic pressure). Increasing the arterial plasma, colloid osmotic pressure raises the glomerular capillary colloid osmotic pressure which in turn decreases GFR***2. Fraction of plasma filtered by the glomerular capillaries (Fdtration fraction) - Increasing the filtration fraction also concentrated the plasma proteins and raise the glomerular colloid osmotic pressure and tend to reduce GFR * Sodium, Inulin, Glucose are freely filtered across glomerular capillaries***Factors that can Decrease the GFR* Renal disease, DM. Hypertension* Urinary tract obstruction (eg kidney stones)* | Renal blood flow. Increased plasma proteins* *** | Arterial pressure (has only small effect due to auto regulation)* | Angiotensin II (drugs that block angiotensin II formation)* | Sympathetic activity. Vasoconstrictor hormones (eg Norepinephrine, epinephrine, endothelin) platelet activing factor, PGF2* Increase Bowman's capsule hydrostatic pressureFactor than can Increase the GFR* Increased glomerular capillary filtration Coefficient (Kt)* Increased glomerular capillary hydrostatic pressure* Endothelial derived Nitric oxide (NO)-| renal vascular resistance -|GFR* Prostaglandins (PGE2) Bradykinin. CAMP, Dopamine, ANP, BNP* High protein intake and increased blood glucose -| renal blood flow and GFRALSO-REMEMBER* Normal filtration fraction varies from 15-20%* Normal net filtration pressure is about 20 mmHg (varies 15-20 mmHg)* Kidney receives about 25% of cardiac out put (1.2 - 1.3 litre of blood per minute)* The tubuloglomerular feed back is mediated by - sensing NaCl concentration in the macula densa*** The prime driving force for counter current multiplier system is - Reabsorption of Na+ in thick ascending limb*** Urinary concentrating ability of the kidney is increased by(i) ECF volume contraction / water deficit(ii) High level of ADH(iii) High osmolarity of renal medullary interstitial fluid* Tc99 DTPA (Diethylene- Pentothenic Acid) is the agent of choice for assessment of GFR*** Patient having acute cardiac failure, do not show edema because there is fall in the systemic capillary hydrostatic pressure

Normal glomerular filtration rate is 625 L/day

| plasma oncotic pressure increases the GFR


Question: Normal diffusion of CO2 at rest

Normal diffusion capacity of co2 is about 400 to 500 ml per minute Ref: guyton and hall textbook of medical physiology 12 edition page number:350,351,352


Question: Inverse stretch reflex is mediated via

Ans. A Golgi tendonRef: Ganong 25th ed. pg. 232* Up to a certain point, harder a muscle is stretched the stronger it will contract. However when the tension becomes great enough, contraction ceases and muscle relaxes. This relaxation in response to strong stretch is called inverse stretch reflex.* The receptor for the same is called Golgi tendon organ. It is a net like connection of knobby nerve findings amongst the fascicles of a tendon.* There are 3-25 muscle fibers per Golgi tendon organ.* The fibres from Golgi tendon organ make up Ib group of myelinated rapidly conducting sensory nerve fibers.


Question: The oxygen dissociation curve of myoglobin & hemoglobin is different due to

The lack of cooperative binding is reflected in myoglobin dissociation curve.,a rectangular hyperbola is obtained. In the case of Hb, a sigmoid curve is obtained. A leftward shift in myoglobin O2 binding curve when compared to Hb demonstrates a higher affinity for O2 and thus promotes a orable transfer of O2 from Hb in the blood.Ref: Ganong&;s Review of medical physiology, 24th edition.Pg no. 643


Question: Hematocrit increases in venous blood due to

CHLORIDE SHFTFor each CO2 molecule added to a red cell, there is an increase of one osmotically active paicle in the cell-- either an HCO3- or a Cl- in the red cell (Figure 36-6). Consequently, the red cells take up water and increase in size. For this reason, plus the fact that a small amount of fluid in the aerial blood returns the lymphatics rather than the veinsThe hematocrit of venous blood is normally 3% greater than that of the aerial blood. In the lungs, the Cl- moves out of the cells and they shrink.Thus increased Cl- in venous blood cause increased hematocrit


Question: Nitrogen narcosis is caused due to

Nitrogen has anesthetic effect on body The precise mechanism is not well understood, but it appears to be the direct effect of gas dissolving into nerve membranes and causing temporary disruption in nerve transmissions. While the effect was first observed with air, other gases including argon, krypton and hydrogen cause very similar effects at higher than atmospheric pressure. Some of these effects may be due to antagonism at NMDAreceptors and potentiation of GABAA receptors,similar to the mechanism of nonpolar anesthetics such diethyl ether or ethylene. However, their reproduction by the very chemically inactive gas argon makes them unlikely to be a strictly chemical bonding to receptors in the usual sense of a chemical bond. An indirect physical effect - such as a change in membrane volume - would therefore be needed to affect the ligand-gated ion channels of nerve cells.Trudell et al. have suggested non-chemical binding due to the attractive van der Waals force between proteins and ine gases. Similar to the mechanism of ethanol's effect, the increase of gas dissolved in nerve cell membranes may cause altered ion permeability propeies of the neural cells' lipid bilayers. The paial pressure of a gas required to cause a measured degree of impairment correlates well with the lipid solubility of the gas: the greater the solubility, the less paial pressure is needed. An early theory, the Meyer-Oveon hypothesis, suggested that narcosis happens when the gas penetrates the lipids of the brain's nerve cells, causing direct mechanical interference with the transmission of signals from one nerve cell to another. More recently, specific types of chemically gated receptors in nerve cells have been identified as being involved with anesthesia and narcosis. However, the basic and most general underlying idea, that nerve transmission is altered in many diffuse areas of the brain as a result of gas molecules dissolved in the nerve cells' fatty membranes, remains largely unchallenged Ref guyton and hall textbook of medical physiology 12/e p1036

Increased solubility of nitrogen in nerve cell membrane


Question: In a normal person at resting condition GFR is

The GFR in a healthy person of average size is approximately 125 mL/min.


Question: The normal total iron binding capacity is


Question: Spontaneous release of acetylcholine at the neuromuscular junction produces

Spontaneous release of acetylcholine in small amounts normally happens in synapses. This can result in miniature end plate potential.


Question: The parvocellular pathway from lateral geniculate nucleus to visual cortex is most sensitive for the stimulus of

The parvocellular pathway, from the lateral geniculate nucleus (Layers 3-6) to the visual cortex, carries signals for the detection of colour vision, texture, shape and fine details.


Question: Presynaptic facilitation is caused by

Presynaptic facilitation: when a third neuron facilitates the presynaptic neuron at it ternimal end is called presynaptic facilitation It causes increased neurotransmitters by opening ca+ channals Ref:Guyton and Hall textbook of medical physiology 12th edition,page number:675,676,677


Question: Cushing reflex, there is

Cushing reflex tends to restore the blood flow to the medulla. Over a considerable range, the blood pressure rise is propoional to the increase in intracranial pressure. The rise in blood pressure causes a reflex decrease in hea rate the aerial baroreceptors. This is why bradycardia rather than tachycardia is characteristically seen in patients with increased intracranial pressure. Ref: Ganong&;s Review of medical physiology 25th edition. Page: 593


Question: Normal range of urine osmolality (mosmol/I)

Normal range of urine osmolality in humans ranges between 300-1200 mosmol/lRef: Ganong&;s Review of Medical Physiology, 23rd edition, page no: 654, 655


Question: Initiation of visual impulse is associated with

Ans. (b) Photoisomerization and hydrolysis of visual purple(Ref: Ganong, 25th ed/p. 179)On exposure to light, there is conversion of 11 cis retinal to All trans retinal (photoisomerization) and hydrolysis of visual pigment

Condensation of opsin with vitamin A aldehyde


Question: In human body the action of surfactant is done by


Question: Fragmented RBCs, sliced by fibrin bands; seen in intravascular haemolysis are known as

Schistocytes: Fragmented RBCs, sliced by fibrin bands; seen in intravascular hemolysis. Burr cells: Irregularly shaped red cells, seen in uremia. Spherocytes: Smaller, spherical cells, appearing more dense, seen in congenital haemolytic anemia or, rarely, in hereditary spherocytosis. Leptocytes (target cells, also called Mexican hat cells): Central staining, a ring of pallor and an outer rim of staining, seen in liver disease, thalassemias, sickle cell disease.


Question: Maximum are a of representation in the motor cortex is for


Question: Regulated bone growth through puberty occurs through


Question: Tumor arising from olfactory nasal mucosa is

Esthesioneuroblastoma is a rare unique tumor of neural crest origin. Presents as a unilateral polypoidal mass in the upper third of the nasal cavity with symptoms of nasal obstruction, epistaxis and anosmia.


Question: The nucleus involved in Papez circuit is

The Papez circuit refers to a closed circuit formed by connections between the cingulate gyrus, hippocampus, mammillary bodies and anterior nucleus of thalamus. This circuit is responsible for resting EEG and for those emotions and aspects of behavior that are related to preservation of the individual and speciesref: guyton and hall textbook of medical physiology 12 edition page number: 826,827,828


Question: Time about milk secretion

Posterior pituitaryThe posterior lobe of the pituitary gland; the neurohypophysis.A preparation of animal posterior pituitary having the pharmacological actions of its hormones, oxytocin, and vasopressin; used mainly as an antidiuretic in the treatment of diabetes insipidus and as a vasoconstrictor.Ref: Ganong&;s review of medical physiology; 24th edition; page no:-311

Neuroendocrine pa of post pituitary is involved

Secretion by contraction of lactiferous sinus oxytocin


Question: Ejection of milk is caused by

Oxytocin plays roles in sexual reproduction, in paicular during and after childbih. It is released in large amounts after distension of the cervix and uterus during labor, facilitating bih, maternal bonding, and, after stimulation of the nipples, breastfeeding. Both childbih and milk ejection result from positive feedback mechanisms.ADH (antidiuretic hormone) a hormone secreted by neurosecretory cells of the HYPOTHALAMUS and released by the posterior lobe of the PITUITARY GLAND. ADH stimulates the reabsorption of water through the distal convoluted tubule of the KIDNEY nephron in mammals and thus limits the water content and the overall volume of urine.Progesterone also known as P4 is a C-21steroid hormone involved in the female menstrual cycle, pregnancy and embryogenesis of humans and other species. Progesterone belongs to a class of hormones called progestogens and is the major naturally occurring human progestogen.thyroxine a thyroid hormone that contains iodine and is a derivative of the amino acid tyrosine, occurring naturally as l-thyroxine; its chemical name is tetraiodothyronine. It is formed and stored in the thyroid follicles as thyroglobulin and released from the gland by the action of a proteolytic enzyme. It is deiodinated in peripheral tissues to form triiodothyronine (T3), which has a greater biological activity.Ref: Ganong&;s review of medical physiology;24th edition; page no-151


Question: In ERG 'A' waves corresponds to

ERG A wave Activity of rods and cones B wave Bipolar cell C wave Retinal pigment epithelium(RPE)


Question: Surfactant lining the alveoli

The low surface tension when the alveoli are small is due to the presence in the fluid lining the alveoli of surfactant, a lipid surface-tension-lowering agent. If the surface tension is not kept low when the alveoli become smaller during expiration, they collapse in accordance with the law of Laplace.

Is produced in alveolar type I cells and secreted into the alveolus.

Is increased in the lungs of heavy smokers.


Question: Fast fatigable motor unit are recruited

White muscle fibers are the fast fatigable motor units and are recruited last Red muscle fibers are rich in mitochondria and hence don't get fatigue soon Ref:Guyton and Hall textbook of medical physiology 12th edition,page number:91,92,93


Question: Amount of gastric juice per day is

A typical adult human stomach will secrete about 1.5 liters of gastric acid daily Ref: guyton and hall textbook of medical physiology 12 edition page number:406,407,408


Question: Maximum oxygen is transpoed in blood

About 99% of the O2 transpoed combines with the O2carrying protein hemoglobinRef: Ganong's Review of Medical Physiology Twenty-Third Edition Page No:609


Question: In tuberculous synovitis of the hip joint the position of the hip is

Extension adduction and internal rotation


Question: Slowest conduction of velocity occurs in

The total delay in the A-V nodal and A-V bundle system is about 0.13 second. This delay, in addition to the initial conduction delay of 0.03 second from the sinus node to the A-V node, makes a total delay of 0.16 second before the excitatory signal finally reaches the contracting muscle of the ventricles.Ref: Guyton and Hall textbook of medical physiology 13th edition. Page:125


Question: Pepsin is activated by

The pepsin precursors are called pepsinogen and are activated by gastric acid.Pepsinogen 1 is found only in acid-secreting regions, whereas pepsinogen 2 is also found in the pyloric region.Pepsins have a pH optimum 1.6-3.2Pepsin hydrolizes the bonds between aromatic amino acids.(Ref: Ganong&;s Review of medical physiology, 23rd edition, page: 455)


Question: Surfactant accelerated by

(Glucocorticoids) (657-Ganong 22nd) (442-A.K. Jain 3rd) (598-Ganong 23rd)* Maturation of surfactant in the lungs is accelerated by glucocorticoid hormones. Fetal and maternal cortisol increases near term and the lungs are rich in glucocorticoid receptors* Nomally after birth, the infant makes several strong inspiratory movements and the lung expand. Surfactant keeps them from collapsing again. But due to deficiency of surfactant in this disease, surface tension in the lungs of these infants is very high, and there are many areas in which alveoli are collapsed (At electasis) also pulmonary oedema occurs and infants dies of pulmonary insufficiency. Infants with RDS show low thyroid hormone and cortisol levels in their plasma.


Question: The vasodilatation produced by carbon dioxide is maximum in one of the following

The vasodilation produced by carbon dioxide is maximum in the brain Ref: guyton and hall textbook of medical physiology 12 edition page number:360,361,362


Question: Perfusion pressure is

Perfusion pressure is arterial pressure minus venous pressure.


Question: NERNST's potential of Na+ is

Nernst potential
Na+- +60mv
K+- -90mv
Cl- - -70mv


Question: 'A' wave in Electro Retinogram corresponds to activity in

The electroretinogram (ERG) is a diagnostic test that measures the electrical activity generated by neural and non-neuronal cells in the retina in response to a light stimulus. The electrical response is a result of a retinal potential generated by light-induced changes in the flux of trans retinal ions, primarily sodium and potassium. A-wave: initial corneal-negative deflection, derived from the cones and rods of the outer photoreceptor layers. This wave reflects the hyperpolarization of the photoreceptors due to closure of sodium ion channels in the outer segment membrane. Absorption of light triggers the rhodopsin to activate transducin, a G-protein. This leads to the activation of cyclic guanosine monophosphate phosphodiesterase (cGMP PDE) eventually leading to a reduction in the level of cGMP within the photoreceptor. This leads to closure of the sodium ion channels resulting in a decrease of inwardly directed sodium ions, or a hyperpolarization of the cell. The a-wave amplitude is measured from baseline to the trough of the A-wave. Ref.textbook of physiology by A K Jain 7th edition page no.1110


Question: HCG is produced by

Chorionic gonadotropin (human chorionic gonadotropin (HCG) (hCG)) is a glycopeptide hormone that is produced by cells of the fetal placenta and maintains the function of the corpus luteum during the first few weeks of pregnancy.Ref: Ganong&;s review of medical physiology;24th edition; page no:-414


Question: Role of liver in vitamin D metabolism

Found in the liver, this enzyme is a microsomal vitamin D hydroxylase that conves vitamin D into 25-hydroxyvitamin D (calcidiol), which is the major circulatory form of the vitamin.


Question: Fine touch and rapidly adapting receptor is

Tactile corpuscles (or Meissner&;s corpuscles) are a type of mechanoreceptor. They are a type of nerve ending in the skin that is responsible for sensitivity to light touch. In paicular, they have highest sensitivity (lowest threshold) when sensing vibrations between 10 and 50 Hez. They are rapidly adaptive receptors. They are most concentrated in thick hairless skin, especially at the finger pads.Ref: Ganong&;s review of medical physiology 23rd edition Page no: 150


Question: Not a component of Brain stem

Brainstem
1. Medulla:responsible for regulating and/ or coordination of:
- Blood pressure.
- Breathing.
- Swallowing.
- Coughing.
- Vomiting.
2. Pons : participates in respiratory regulation and the relay of information from cerebral hemispheres to the cerebellum.
3. Midbrain : participates in coordination of visual and auditory systems.


Question: A baby boy is brought to the hospital because of convulsion. In the course of work up his body temperature & plasma glucose are normal but his CSF glucose is 12 mg/ dl. A possible explanation is

Ans: c (GLUT 1 55K deficiency in capillaries) Ref: Ganong, 22nd ed, p. 615It is a direct pick from self study MCQs in Ganong.According to the given parameters there is deficient transport of glucose across brain capillaries.The predominant GLUT in the brain is GLUT-1 55 K (Ganong p. 615). GLUT-1 45 K is also present in brain capillaries and not in microglia.GLUT 1 - RBC, brain, kidney, placenta, retinaGLUT 2 - Liver, B cells of pancreasGLUT 3 - BrainGLUT 4 - Skin, cardiac muscle, adipose tissueGLUT 5 - Testes, spermsGLUT 7 - Liver, endoplasmic reticulumNote:GLUT 4 is mediated by insulin.GLUT 5 is used as a fructose transporter (semen).

GLUT 5 deficiency in cerebral capillaries


Question: Effect of coisol

The principal glucocoicoid produced by the zona fasciculata of the adrenal coex. It promotes gluconeogenesis and lipolysis, suppresses protein synthesis, inhibits inflammatory and immune responses, and has mild mineralocoicoid (for example, hypernatremic, kaliuretic, antidiuretic) effects. Most plasma coisol is bound to transcoin and albumin. Synthetic coisol administered as a drug is usually known by the alternative name hydrocoisone.Ref: Ganong&;s review of medical physiology;24th edition; page no-362


Question: Intrapleural pressure is

In physiology, intrapleural pressure (also called intrathoracic pressure) refers to the pressure within the pleural cavity. Normally, the pressure within the pleural cavity is slightly less than the atmospheric pressure, in what is known as negative pressure Ref: guyton and hall textbook of medical physiology 12 edition page number: 316,317,318

Transpulmonary pressure + Alveolar pressure

Transpulmonary pressure - Alveolar pressure

Alveolar pressure - Transpulmonary pressure


Question: Swan Ganz Catheter is used to measure

The pulmonary aery catheter allows direct, simultaneous measurement of pressures in the right atrium, right ventricle, pulmonary aery, and the filling pressure ("wedge" pressure) of the left atrium.


Question: Intrinsic factor secreted by

Parietal or oxyntic cells secrete HCl and intrinsic factor.Chief or zymogen or peptic cells secrete pepsinogen.(Ref: Ganong&;s Review of medical physiology, 23 rd edition, page 431)


Question: Gap junctions are present in

(Smooth muscles) (13-K.S) (92-559-771-Gyton 11th) (16,17,78,85-GN) (39-40-Ganong 23rd)GAP-JUNCTIONS is also called nexus. It is present in heart, basal part of epithelial cells of intestinal mucosa* Gap Junctions - small protein tubular structures, that allow free-free movements of ions from the interior of one cell to the interior of the next. Only a few gap junctions have been found in the CNS. However it is by way of gap junctions and other similar junctions that action potentials are transmitted from one smooth muscle fibre to the next in visceral smooth muscle and from one cardiac muscle cell to the next cardiac muscle (559- Gyton 11th)* Regulation of the diameter of channels in Gap junctions-by the intracellular calcium-ions, also by pH, voltage, hormones or neurotransmitters.


Question: Gastric emptying is mainly regulated by

Gastric emptying is mainly regulated by enteric reflexes. Regulation of gastric emptying is mainly by the inhibitory feedback signals from the duodenum that includes enterogastric reflex and hormonal feedback by cholecystokinin. Enterogastric reflex: When food enters the duodenum , multiple nervous reflexes are inititiated from the duodenal wall. They strongly inhibit the pyloric pump propulsive contractions and increase the tone of the pyloric sphincter. These reflexes are mediated by three routes: Directly from the duodenum to the stomach through the enteric nervous system in the gut wall(major role) Through inhibitory sympathetic nerve fibers to the stomach (minor role) Vagus nerves to the brainstem where they inhibit the normal excitatory signals transmitted to the stomach (minor role) Cholecystokinin is released from the mucosa of the jejunum in response to fatty substances in the chyme. This hormone acts as an inhibitor to block increased stomach motility caused by gastrin. Ref: Guyton and Hall 13th edition Pgno: 812


Question: Stapes rests in

(C) Oval window > The stapes is named for its resemblance to a stirrup> Stapes foot-plate is attached by an annular ligament to the walls of the oval window.


Question: Stretch reflex of bladder is integrated at

The bladder smooth muscle has some inherent contractile activity; however, when its nerve supply is intact, stretch receptors in the bladder wall initiate a reflex contraction that has a lower threshold than the inherent contractile response of the muscle. Fibers in the pelvic nerves are the afferent limb of the voiding reflex, and the parasympathetic fibers to the bladder that constitute the efferent limb also travel in these nerves. The reflex is integrated in the sacral poion of the spinal cord.Ref: Ganong&;s review of medical physiology,23rd edition, page: 662


Question: Ovulation of ovary is influenced by

Ovulation is the release of egg from the ovaries. In humans, this event occurs when the de Graaf&;s follicles rupture and release the secondary oocyte ovarian cells.Luteinizing hormone (LH, also known as lutropin and sometimes lutrophin is a hormone produced by gonadotropic cells in the anterior pituitary gland. In females, an acute rise of LH ("LH surge") triggers ovulation and development of the corpus luteum. In males, where LH had also been called interstitial cell-stimulating hormone (ICSH), it stimulates Leydig cell production of testosterone. It acts synergistically with FSH.Ref: Ganong&;s review of medical physiology; 24th edition; page no:-401


Question: A man is given continuous testosterone. It would lead to

Testosterone the principal male sex hormone (androgen) that is produced by Leydig&;s cells of the testes in response to luteinizing hormone secreted by the pituitary gland. It is also produced by the adrenal coex in both males and females. Its chief function is to stimulate the development of the male reproductive organs, including the prostate, and the secondary sexcharacters, such as the beard. It encourages growth of bone and muscle,Azoospermia is defined as the lack of spermatozoa in the semen. It may be caused by testicular dysfunction, cancer chemotherapy, or blockage of the tubules of the epididymis, or it may be induced by vasectomy.Ref: Ganong&;s review of medical physiology; 24th edition; page no:-419


Question: Thrombin activity is inhibited by

Heparin is present in the luminal surface of vascular endothelium it acts as an anticoagulation by the following mechanism: Prevent conversion of prothrombin to thrombin Inhibit the action of thrombin Facilitate the action of antithrombin III Ref: Medical Physiology Indu Khurana 2015 edition, Page No:159 It is also used as intravenous anticoagulant. Dose-0.5 to 1mg/kg of bodyweight. Action lasts for 1.5 to 4 hrs Injected heparin is destroyed by an enzyme in blood called heparinase


Question: Stimulation of the apneustic centre causes

The apneustic centre is located in the lower pons and it stimulates the inspiratory center to increase inspiratory activity. The apneustic center of pons sends signals to the DRG in the medulla to delay the &;Switch off&; Signal of the inspiratory ramp provided by pneumotaxic center of pons. It gets feedback from the vagal afferents and also from other respiratory centers. The apneustic center is inhibited by vagal afferents from pulmonary stretch receptors aroused by inspiration so that stimulatory effect on the inspiratory neurons is switched off allowing expiration to supervene. Respiratory Center components Primary function Pre-Botzinger complex Pacemaker cells of spontaneous or automatic breathing Dorsal Respiratory Group (DRG) Respiratory rhythm generator (inspiratory ramp signal) Ventral Respiratory Group (VRG) Overdrive mechanism Pneumotaxic center Controls the "switch off" point of inspiratory ramp signal Apneustic centre Delays switch off signal-Promotes inspiration Vagi Inhibits inspiratory discharge Ref: Guyton and Hall 13th edition Pgno: 538-548


Question: In determining blood pressure by auscultatory method

The loudest sound is the diastolic pressure

Systolic pressure estimation tends to be lower than those made by palpatory method

The first sound heard is the systolic pressure

The sounds that are heard are generated in heart


Question: Leydig cells secrete

Leydig cells are the cells between the seminiferous tubules of the testis that secrete testosterone.Ref: Ganong&;s review of medical physiology; 24th edition; page no:-394


Question: Osmolarity of plasma is

Plasma Osmolarity :it is a measure of hydration status.plasma Osmolarity changes during dehydration and rehydration. Plasma Osmolarity ranges from 280 to 300 mOs/kg Ref:Guyton and Hall textbook of medical physiology 12th edition ,pag number:45 46


Question: A 10 degree decrease in temperature causes decrease in cerebral metabolic rate by

Metabolism reduces by 6.7% for every 10C fall in temperature.


Question: The length of distal convoluted tubule is

Although the DCT is the shoest segment of the nephron, spanning only about 5 mm in length in humans (1), it plays a critical role in a variety of homeostatic processes, including sodium chloride reabsorption, potassium secretion, and calcium and magnesium handling Ref: guyton and hall textbook of medical physiology 12 edition page number:460,461,462


Question: Ventrolateral cordotomy for the relief of pain in the left lower limb is effective due to the cutting of

Fibres from nociceptors and thermoreceptors synapse on neurons in the dorsal horn of the spinal cord. The axons from these dorsal horn neurons cross the midline and ascend in the ventrolateral quadrant of the spinal cord, where they form the ventrolateral spinothalamic pathway.


Question: Pronator drift test is done for lesion of

When the patient extends both arms upright in the supinated position and holds them at shoulder height for at least 10 seconds (Patients should be asked to keep eyes open initially and later test again with eyes closed):Normal response:Palm will remain flat, elbows straight and the limbs horizontal ORSymmetrical detion from this position (i.e. on both the sides - dominant hand may pronate slightly more than the non-dominant hand)Positive pronator drift: Components of pronator drift as mentioned above is seen in the weaker side (asymmetric response) which indicates a lesion in contralateralPseduodrift:Slight pronation, without downward drift of the dominant armNot necessarily abnormal - must be interpreted in clinical context InterpretationPositive with eyes open: Motor deficitPositive with eyes closed: Sensory deficit (Posterior column)Outward and upward drift: Cerebellar drift"Updrift" (involved arm rising overhead without patient awareness): Parietal lobe lesions (loss of position sense)Drift without pronation: Functional upper limb paresis (Conversion disorder)Ref: Ganong&;s review of medical physiology, 23rd edition, Page no:242


Question: Osmotic pressure of 1 mol of ideal solute relative to pure water is

According to the Van't Hoff equation, an ideal solution containing 1 mole of dissolved paicles per liter of solvent at 0deg C will have an osmotic pressure of 22.4 atm Ref guyton and hall textbook of medical physiology 12/e pg159


Question: Hot water bottle relieves the pain of abdominal spasm by

Pain from gastrointestinal viscera is carried by small C fibers. Temperature sensation from hot water bottles passes through A fibers and large C fibers.
When these larger fibers are stimulated, they block the adrenergic small C fibers from the viscera.


Question: Glucose reabsorption occurs in the

Glucose, amino acids, and bicarbonate are reabsorbed along with Na+ in the early portion of the proximal tubule.


Question: Dysmetria is seen in lesion of

Dysmetria or past- pointing is a prompt initiation for a gross corrective action as attempting to touch an object with a finger results in overshooting to one or other side , but the correction overshoots to the other side. And finger oscillates to and fro. This is typically seen in cerebellar disease. Ref:Ganongs Review of medical physiology;23 rd edition ; pg :258


Question: A herpetologist is bitten by a poisonous snake and is taken to the emergency depament with progressive muscle paralysis. The venom is probably incapacitating his

Snake venom usually blocks acetylcholine receptors, preventing depolarization of the muscle cell. The Na+ and Ca2+ channels are not incapacitated by snake venoms


Question: Na+ channel concentration is highest at

Axon hillock has greatest in a sodium plus channel concentration Ref : guyton and hall textbook of medical physiology 12 edition page number:66,67,68


Question: Aeriole is

The small aeries and aerioles are referred to as resistance vessels because they are the principal site of the peripheral resistance A large amount of blood can be added to the venous system before the veins become distended to the point where fuher increments in volume produce a large rise in venous pressure. The veins are therefore called capacitance vesselsExchange across the capillary walls is essential to the survival of the tissues. Thus capillaries are exchange vesselsElastic aery is otherwise called conducting aeryRef: Ganong's Review of Medical Physiology Twenty-Third Edition Page No:543


Question: Increase in cytosolic calcium from intracellular storage, during smooth muscle contraction, is/are due to

In smooth muscle contraction, calcium channels are opened causing an influx of calcium into the cell. In smooth muscle cells, agonists such as neurotransmitters or hormones can induce an increase in (i) a release of intracellular stored calcium or/and an influxof extracellular calcium. ... These channels control phenomena such as smooth musclecells proliferation and/or contraction. (REF: TEXTBOOK OF MEDICAL PHYSIOLOGY GEETHA N 2 EDITION, PAGE NO - 59)


Question: The amount of body water in human body is

60% of the body contains water Ref: guyton and hall textbook of medical physiology 12 edition page number:45,46,47


Question: Normal poal venous pressure is

Poal venous pressure is normally about 10 mm Hg in humans, and hepatic venous pressure is approximately 5 mm Hg.Ref: Ganong&;s Review of medical physiology 25th edition. Page: 509


Question: Slow waves/BER maximum in

Except in the esophagus and the proximal poion of the stomach, the smooth muscle of the gastrointestinal tract has spontaneous rhythmic fluctuations in membrane potential between about -65 and -45 mV. This basic electrical rhythm (BER) is initiated by the interstitial cells of Cajal, stellate mesenchymal pacemaker cells with smooth muscle-like features that send long multiply branched processes into the intestinal smooth muscle. In the stomach and the small intestine, these cells are located in the outer circular muscle layer near the myenteric plexus; in the colon, they are at the submucosal border of the circular muscle layer. In the stomach and small intestine, there is a descending gradient in pacemaker frequency, and as in the hea, the pacemaker with the highest frequency usually dominates. The BER itself rarely causes muscle contraction, but spike potentials superimposed on the most depolarizing poions of the BER waves do increase muscle tension. The depolarizing poion of each spike is due to Ca2+ influx, and the repolarizing poion is due to K+efflux. Many polypeptides and neurotransmitters affect the BER. For example, acetylcholine increases the number of spikes and the tension of the smooth muscle, whereas epinephrine decreases the number of spikes and the tension. The rate of the BER is about 4/min in the stomach. It is about 12/min in the duodenum and falls to about 8/min in the distal ileum. In the colon, the BER rate rises from about 2/min at the cecum to about 6/min at the sigmoid. The function of the BER is to coordinate peristaltic and other motor activity; contractions occur only during the depolarizing pa of the waves. After vagotomy or transection of the stomach wall, for example, peristalsis in the stomach becomes irregular and chaotic.REF: GANONG&;S REVIEW OF MEDICAL PHYSIOLOGYKIM BARRETT, HEDDWEN BROOKS, SCOTT BOITANO, SUSAN BARMAN, TWENTY-THIRD EDITION PAGE NO:470


Question: The titin protein present in the muscle fibre binds

The titin protein present in the muscle fibre binds the head ends of myosin filaments to the Z-disc Several proteins other than actin and myosin are also present in the muscle. Some of them include: 1. Titin It is the largest known protein It runs between the M line and Z disc and binds the head ends of myosin filaments to the Z disc. It has a tethered poion in the A band , where it is attached to the myosin filament and an elastic poion in the I band. The elastic propey of the titin causes elastic recoil of the sarcomere and prevents it from being overstretched. 2.Nebulin It extends from the Z disc and runs along the full length of each actin filament. It regulates the length of the actin filament. 3. a-actinin It is a component of the Z discs It binds the plus ends of actin filament to this disc. 4. Myomesin It is present in the region of the M line. It maintains the regular lattice arrangement of the myosin filaments in this region. 5. Desmin: It is an intermediate filament characteritic of the muscle. It encircles the myofibrils near the Z disc and binds myofibrils to each other and also to the cell membrane. 6. Dystrophin It is present in the periphery of the muscle fibre, towards the cytoplasmic face of the sarcolemma. It binds to the actin filaments and the glycoprotein complex, consisting of the dystroglycan and sarcoglycan that spans the sarcolemma. Ref: Inderbir Singh's Textbook of Human Histology 8th edition Pgno: 80

The tail ends of actin filaments to Z disc

The tail ends of myosin filaments to the Z disc

The tail end of myosin filaments to M disc

The myofibrils to each other, and also to the cell membrane


Question: The tendency for turbulent flow is greatest in

The tendency for turbulent flow is greatest in the aoa. The turbulence of flow depends upon Reynold&;s Number: Reynold&;s Number Type of Blood flow <2000 Laminar 2000-3000 Transitional >4000 Turbulent In the proximal poions of the aoa and pulmonary aery, Reynold&;s Number can rise to several thousand during the rapid phase of the ejection, which causes considerable turbulence due to following High velocity of blood flow Pulsatile nature of the flow Sudden changes in vessel diameter Large vessel diameter Ref: Guyton and Hall 13th edition Pgno: 174


Question: Glucose is primarily absorbed from

Important educational points

60-70% of glomerular filtrate is reabsorbed in the proximal tubule.

Na+ reabsorption occurs in all segments of nephron excepting descending limb of the loop of Henle. 60% (60- 70%) of filtered Na+ is reabsorbed in the proximal tubule. About 30% of filtered Na+ is reabsorbed in the thick ascending limb of the loop of Henle. About 7% of filtered Na+ is reabsorbed in early distal tubules and about 3% of filtered sodium is reabsorbed in late distal tubule and collecting duct.

About 65% (60-70%) of water is reabsorbed in the proximal tubule and about 15% of water is reabsorbed in the thin descending limb. Remaining 20% of water enters the distal tubules and is absorbed from distal tubule and collecting duct according to the homeostatic requirements of the body, under the control of ADH.

All substances (Na +, K +, HCO3, Cl-, Phosphate, Protein, Glucose, water) are maximally absorbed in the proximal tubule.

Glucose and amino acids are completely absorbed from proximal tubules along with Na + as secondary active transport cotransport (symport).

H + is not absorbed by nephrons anywhere it is only secreted (in the proximal tubule, late distal tubule and cortical collecting tubules). Substances which are both secreted and reabsorbed are K +, uric acid and creatinine.

On a normal diet, maximum solutes are reabsorbed almost completely: Glucose: 100%, Aminoacids 100%, HCO3-: 100%. Water: 99.4%, Na + : 99.4%, Cl-: 99.2%, Uric acid : 98%, K+ : 93.3%, Urea : 53%, and Total solutes : 98.9%

Amount secreted per day of different filtered contents are : Na+ : 150 mEq/d, K + : 90 mEq/d, Cl - : 150 mEq/d, Glucose: 0, Amino acid: 0, HCO3 : 0, Uric acid: 5 mmol/d. Creatinine: 12 mmol/d, Urea: 410 mmol/d, Water: 1-1.5 L/d; and total solutes : 700 mOsm/d


Question: Contractility of cardiac muscle depends on

Excitation and contraction coupling is there in cardiac muscle. When an action potential reaches the T tubules there is activation of Dihydropyridine channels. This causes influx of extracellular calcium into sarcoplasm. Ref: Textbook of medical physiology by N Geetha, 2nd edition, page no. 53


Question: Capacitance of sperms takes place in

Sperm is the male reproductive cell in the sexual reproduction. Capacitation is the penultimate step in the maturation of mammalian spermatozoa and is required to render them competent to feilize an oocyte. This step is a biochemical event; the sperm moves normally and looks mature prior to capacitation. In vivo, this step typically occurs after ejaculation, in the female reproductive tract. Ref: Ganong&;s review of medical physiology; 24th edition; page no:-422


Question: Therapeutic plasma level of digoxin is

Oral absorption of digoxin is 60-80 %Plasma half-life is about 40 hrsToxic concentration is >2ng/ml(Ref: Essentials of medical pharmacology, K.D Tripathi, 7th edition)


Question: Calcium ions in skeletal muscles are

Spread of depolarization to terminal cistern with release of Ca2+ in the myofibrils.(Ref: Textbook of physiology AK Jain 5th edition page no.166)


Question: Ghrelin is responsible for

Ghrelin: A naturally occurring 28-amino acid; gut-brain growth hormone releasing peptide (GHRP) that is expressed mainly in the stomach and possibly in the hypothalamus. Fasting and hypoglycemia increase ghrelin levels and circulating ghrelin levels are decreased in chronic obesity, following acute caloric intake and in states of positive energy balance. Acute administration of ghrelin to humans induces a feeling of hunger. Ghrelin binds to ghrelin-receptors in the anterior pituitary and possibly in the mediobasal and mediolateral hypothalamus to stimulate growth hormone release and to regulate energy homeostasis. Serum levels of ghrelin are measurably higher in patients who have lost weight through dietary measures.Ref: Ganong&;s review of medical physiology 23rd edition Page no: 384


Question: Conn syndrome is seen due to increased production of

An adrenocoical disorder caused by excessive secretion of aldosterone. ; primary aldosteronismPrimary aldosteronism is an adrenocoical disorder caused by excessive secretion of aldosterone and characterized by headaches, nocturia, polyuria, fatigue, hypeension, potassium depletion, hypokalemic alkalosis, hypervolemia, and decreased plasma renin activity; may be associated with small benign adrenocoical adenomas.Ref: Ganong&;s review of medical physiology; 24th edition; page no:-364