Last moment revisions in Physiology & Biochemistry
Dr Ajithkumar DS
- Kidney contains about 10 lac nephrons.
- Ratio of Juxtamedullary nephrons to cortical nephrons is 90: 10.
- The half life of circulating growth hormone in humans is 20 to 30 minutes.
- The total volume of GIT secretions per day is about 8000 ml.
- The insensible water loss from the body is about 600 to 800 ml. per day.
- Gluteus maximus can exert a tension of 1200 kg.
- The wave lenghts of visible light are approximately 397 to 723 nm.
- Red cell vol. can be determined by radio isotope 51 Cr.
- The human eye has a refractive power of approximately 66.7 diopters at rest.
- Under basal conditions, 35% of the calorie needs of the heart are met by carbohydrate, 5% by ketones and amino acids and rest 60%) by fatty acids (fat)
- On an average, each neuron divides to form 1000 synaptic endings, and since there are 1012 neurons in the human brain, it follows that there are about 10 synapses.
- An average end plate contains about 50 million aceylcholine receptors. Each nerve impulse releases about 60 acetylcholin vesicles, and each vesicles contains about 10,000 molecules of the neurotransmitter. This amount is enough to activate about 10 times the number of acetylcholine receptors needed to produce a full end plate potential.
- Each taste bud is supplied by about 50 nerve fibres and each nerve fibre receives input from an average of 5 taste buds. Each taste bud is replaced every 10 days. There are a total of about 10,000 taste buds.
- Human can distinguish between 2000 to 4000 different odours, this has been demonstrated by the 2-deoxyglucose method. The membrane potential of inner ear hair cells is about is 60 mV. The Sound frequencies audible to human range from 20 to a maximum of 20,000 cps.
- The threshold of human ear varies with the pitch of the sound, the greatest sensitivity being in the 1000 to 4000 Hz range.
- Average 70 kg man has 0.1 kg of glycogen in his liver, 0.4 of glycogen in his muscles, and 12kg of fat. The glycogen is enough fuel for about 1 day of starvation.
- The turnover rate of endogenous proteins avenges 80 to 100 gm per day, being highest in the intestinal mucosa and practically zero in collagen.
- The total area of all the capillary walls in the body exceeds 6300 in the adult.
- There are about 100,000 acini in the human liver.
- Diaphragm accounts for 75% of the change in intrathoracic volume during quiet inspiration. The other important inspiratory are external intercostal muscles.
- The major constituent of surfactant is phosphatidyl colin 62%
- Glia cells are very abundant and as many as 10 to 50 times as neurons.
- The Schwann cells that invest axons in peripheral nerve are classified as glia.
- The myelin sheath envelops the axon except at its ending and at the nodes of Raniver,
- The muscle ruptures when it is stretched to about 3 times its equilibrium length.
- The overall mechanical efficiency of skeletal muscle ranges upto 50% while lifting a weight during isotonic contraction and is essentially 0% during isometric contraction.
- The hypothalamus contains both gastrins 17 and gastrin 34.
- An average of 26,000 receptor cell axons converge on each glomerulus.
- The concentration of odour producing substance must be changed by about 30% before a difference can be detected, while the comparable visual discrimination threshold is a 1% change in light intensity.
- The pitch of the average male voice in conversation is about 120 Hz and that of the average female voice about 250 Hz.
- The total number of afferent and efferent fibres in each auditory nerve is approximately 28,000
- Whistle of blue whale is as loud as 180 dB and is audible for 100 miles.
- The normal fasting level of glucose in peripheral venous blood is 70 to 110 mg/dL while in arterial blood its level is 15 to3O mg/dL higher than the venous blood.
- The BMR of a man of average size is about 2000 Kcall/day.
- The net production per mole of blood glucose metabolised aerobically via the Embden Myeyerhof pathway and TCA cycle is 38 moL of ATP.
- The normal blood uric acid in human is approximately 4 mg/dL
- The 02 consumption of human brain averages about 35 ml/l00 gm brain (49 ml/min for the whole brain) in an adult.
- Portal venous pressure is normally about 10 mm Hg in humans, and hepatic venous pressure approx. 5 mm Hg.
- The Hb mols contains 38 histidine residues and on this basis -the Hb in blood has 6 times the buffering capacity of the plasma proteins.
- The blood flow in each 2mg carotid body is about 0.04 mI/m or 2000 ml per 100 g of tissue per minute, compared will blood flow per 100 g per minute of 54 ml in the brain and 420 ml in the kidney.
- Cyanosis appears when the reduced Hb conc. of the blood in the capillaries is more than 5 gm/dI.
- The GFR in an average sized normal man is approximately 125 mi/minute. At the rate of 125 mI/mm, the kidneys filter in I day The. amount of fluid equal to 4 times the TBW, 15 times the ECF vol. and 60 times the plasma volume.
- Juxta medullary nephrons constitute 90% of total nephrons.
- Motor area of Bradman is area 4.
- Upto 65 mm Hg systolic pressure, brain is capable of autoregulation.
- In vitro, coagulation is initiated by factor XJI.
- Life of RBCs in adult human body is 120 days.
- Normal value of FEVI in an adult male is 80%.
- Normal basic acid output is 5-10 m.mol/hour.
- Urine osmolality in diabetes insipidus is 300 mmol/l.
- Under resting condition, cardiac output is 5.25 L/mm.
- The number of iron items in one Hb molecule is 4.
- Normal GFR is 125 mI/min.
- Normal protein excretion is 50-150 mg%.
- The number of 02 molecules carried by one Hb molecule is 4.
- The normal serum calcium is 9-11 mg%.
- The quantity of water lost as sweat per day is 600-800 C.C.
- Cardiac cycle duration in man is 0.8 seconds.
- In an average adult, the stroke volume per mm is 60-70 C.C.
- Normal hepatic blood flow per minute is 100 C.C./100 gm of liver tissue.
- An adult pancreas has 2.5-7.5 lac islets.
- Normal amount of C.S.F. in man is 150 c.c.
- Normal A: G ratioof blood is 2:1.
- Linear Velocity of blood at normal cardiac output in aorta is 32 cm/sec.
- Intrapleural pressure at the end of deep inspiration is 4mm Hg.
- The diffusion capacity for carbon dioxide as compared to that of 02 is 20 times.
- Ortho phosphoric acid possesses 3pKa values.
- Average life span of RBC in a newborn is 100 days.
- Average life span of RBC in transfused blood is 90 days.
- The duration of spinal shock in man is 2 weeks.
- Hemophilia is caused by deficiency of factor VI
- Peak testesterone levels are seen at 7-8 A.M.
- The cortical layer stimulated most by the diffuse thalamo cortical system is layer 4.
- Normal urea clearance is 44 ml/min
- Half life of transfused platelets is 4 days.
- Face is represented by Brodman area 3
- The rate of conduction of action potentials in Purkinje fibres is about 2.m/sec
- Wallerian degeneration of ruptured nerve starts in 6 hours.
- For each 1°F rise in temperature, cerebral blood flow falls by 7%.
- Alveolor ventilation at rest is 4.2 Urn ‘
- The frequency of Burger waves or alpha waves on EEG is 7-13/sec.
- Maximum voluntary ventilation is 125-170 L /min.
- At each menstrual period, upto 20 gm of protein may be lost.
- MCHC is 34 gl/dl.
- The pressure in left ventricle in diastole is 0 mm Hg.
- The value of resting membrane potential in a nerve fibre is -70 mV.
- During light sleep, sleep spindles have a frequency of 14-16 sec.
- For normal adult eye, near point is situated at 14 cm.
- Resting nerve membrane is more permeable to K÷ than to Na+ by 50-100 times.
- Normal tidal volume is 500 ml.
- Average number of muscle fibres attached to one Golgi tendon organ are 10-15.
- Maximum rate of axonal transport is 400 mm/day.
- Sperms are normally motile at a rate of 1-3 cm/min
- The pyramidal fibres making direct synaptic connections with motor neurons are 10%.
- Sound becomes painful above 140 db.
- Average pH of semen is 7.5.
- Total area of the alveolar walls in contact with capillaries in both lungs is about 70 sq. m.
- There about 300 million alveoli in man.
- Maximum work of breathing is 10 kg/breath.
- Work done in quiet breathing is 0.5 kgm/breath.
- Functional residual capacity in a male is 2.2 litres.
- Timed vital capacity in 1 sec. is 83%.
- Respiratory minute volume is 6.0 litres.
- Diffusion capacity of lungs for 02, at rest is 20 mI/m
- Circulation time through pulmonary capillaries is less than 1 sec.
- At 3000m in above sea level, P02, is about 60 mm Hg.
- Hemoglobin has 210 times more affinity for carbon monoxide than O2
- Donation of I litre of blood causes loss of about 200gm proteins.
- Oxygen toxicity limits exposures to less than 5 hours and exposures to 3 atmospheres or less.
- Urine – plasma ratio of creatinine is 150 mg/dl.
- Blood flow in carotid body is 2000 m g of tissue.
- There is no stimulation of ventilation by hypoxia until the alveolar p02 falls below 60 mm Hg.
- In sternuous exercise, P02 falls from 40 to 15 mm Hg.
- Respiratory minute volume in a normal person is 6.0 L/min.
- Renal blood flow s 25% of cardiac output.
- Urine/plasma ratio of Na+ is 1 meq/L.
- In humans 15% of nephrons have long nephrons.
- Urine plasma ratio of glucose is 0 mg/dl
- Total length of distal convoluted tubule is 5mm.
- Normal non fasting blood ketone level is 2-10 mg%.
- Life span of platelets is 9-12 days.
- The duration of 53 is 0.1sec.
- Normal A-V difference at rest is 4.3 ml.
- Stroke volume at rest is 80-100 ml.
- The duration and frequency of SI is 0.15 sec and 30.
- Cardiac index in a normal person is 3.2
- The average normal arm to tongue circulation is 15 sec.
- Timed vital capacity in 2 sec. is 94%.
- Diffusion capacity of lungs for C02 is 10-30 ml/min/mn/Hg.
- Anatomical dead space is 100-250 ml.
- Plasma C02 content is 25-28 mm/L.
- When osmotic fragility is normal, RBC’s begin to hemolyse when suspended in 0.48% saline.
- Oxygen transported from lung to tissues in chemical combination is 97%.
- In a healthy adult, 24 hour production of C02 is about 330 litres.
- Blood flow reaching the liver via portal versus hepatic artery is 4: 1.
- Hepatic venous pressure is 5 mm Hg.
- C02 excreted per minute is 200 ml.
- 250 ml of oxygen enters the body per minute.
- Pressure in right ventricle during systole is 25 mm Hg.
- Respiratory Quotient of cerebral tissue is 0.95-0.99.
- Oxygen consumption of human brain is 3.5 mI/100 g/mini or 49 mI/m
- Heart receives about 5% of cardiac output.
- Coronary blood flow at rest is 250 ml/mm.
- The blood in systemic arteries which bypass the pulmonary capillaries is about 2%.
- The presence of Hb increases the 02 carrying capacity of the blood by 70 fold.
- Normal composition of venous blood is P02 – 40 mmHg, pCO2 -46 mm Hg and Hb saturation 75%.
- In arterial blood, saturated Hb with 02 is 97%.
- The maximum force that can be applied on a muscle without producing injury is 100g.
- Normal serum K+ is 3.5-5.5 meq/L.
- Peak expiratory flow rate is 400-500 L/mt.
- Splanchnic vessels and venules contain 20-30% of blood volume.
- Each taste bud consists of 4 types of cells and is supplied by about 50 nerve fibres.
- Cells more than 95 ft MCV.are called macrocytes
- Mean corpuscular diameter is 7.5 nm.
- Following acute failure of left ventricle of heart in man, pulmonary edema generally begins to appear when left atrial pressure approaches 30 mm Hg.
- Maximum concentration of Hb normally found in RBC’s is 34%.
- Daily secretions of GIT is 8000 ml.
- The Betz cells of the primary motor cortex are located in Layer V of cortex.
- 95 % of bile salts is normally reabsorbed and then resecreted by the liver.
- In Parkinsonism, tremor is 6-8 per second.
- Each kidney contains about 1 million (10 lac) nephrons.
- The viability of spermatozoa within the female genital tract is upto 24 hours.
- The number of synaptic knobs applied to a single motor neurone has been calculated to be about 10,000 with 2000 on the cell body and 8000 on the dendrites.
- Under basal conditions, 35% of the calorie needs of the heart are met by carbohydrates, 5% by ketones and amino acids and rest (60%) by fatty acids.
- Human skeletal muscle can exert 3-4 kg of tension per sq. cm of cross sectional area.
- In cerebral cortex, 98% of synapses are on dendrites and 2% are on bodies.
- Each taste bud is replaced every 10 days.
- Total length of nephrons including the collecting ducts ranges from 45-65 mm
- The volume of blood in the renal capillaries at any given time is 30-40 ml.
- Renal blood flow is 1.2-1.3 L/min.
- A-VO2 difference in kidneys is 18 ml/L of blood.
- Oxygen consumption of human kidney is about 18 mI/m
- Oxygen consumption of renal cortex and inner medulla are 9 and 0.4 ml/100g/min respectively.
- Bicarbonate level in plasma is about 27 meq/L.
- Sodium filtered per minute is 18125 microequivalents.
- The first urge to void is felt when bladder volume is about 150 ml.
- PH of gastric HC1 is 0.8.
- Alkalosis occurs when pH is above 7.40.
- Extra cellular component accounts for 20% of body weight.
- Exchangeable K÷ in body is 89.6%.
- Total non-exchangeable body sodium in body is 29.3%.
- In an average male, 18-40 years age group has the maximum total body water.
- Normal iron binding capacity is 250-350 u.g/l0O ml.
- Normal range of serum magnesium in blood is 1.5-2.5 meq/L.
- Total body sodium is 58 meq/Kg.
- Normal QRS interval is 0.08-0.1 sec.
- In a man weighing 70Kg, water content of body is 40-45 L.
- R-wave in healthy subjects denotes a dipole with an electrical axis of 60degree.
- Intestinal epithelium turns over in its entirety every 24 to 72 hours.
- Speed of human sperm in female genital tract is about 3 mmmin
- Normal interval for Synaptic delay is 0.5 ms.
- REM sleep constitutes about 25% of total steep.
- Total volume of pancreatic secretion per day is 2.5 litres.
- Interapleural pressure (recoil pressure) required to prevent collapse of the lung 4mm Hg in presence of surfactant.
- Compliance of the normal lungs and thorax combined —0.13 liter/cm. of H20.
- Compliance of the normal lungs alone is 0.22 liter of H20.
- During normal quiet breathing only 2-3% of the total energy expenditure is needed for pulmonary ventilation.
- Normal dead space air volume —150 ml.
- The amount of alveolar air replaced by new atmospheric air with each breath is only 1/7th
- Expired air contains 2/3rd alveolar air + 1/3rd dead space air.
- 97% of 02 is transported by Hb, rest 3% is in dissolved state in the water of the plasma and cells.
- At p02 of 100mm Hg. 02 saturation is 97% while at p02 of 40mm Hg02 saturation is 70%.
- Carbon monoxide binds with Hb, 230 times more strongly than 02.
- Under resting conditions each 100 ml of blood transports 5 ml of 02 to tissues and carries 4 ml of C02 from tissues to the lungs.
- Hering-Breuer reflex is activated only when the tidal volume increases to greater than 1.5 liters.
- Each glomerulus is a net work of approximately 50 parellel capillaries.
- A particle more than 70 inch size is not filtered through the glomerular membrane
- Osmolality at tip of medulla is 1200 mosm/Lit.
- Death occurs usually when the pH of the blood falls to 6.9.
- Amount of fluid present normally in pericardial cavity less than 50 ml.
- Normal basal output is 5-10 mmolar/hr
- Urinary osmolality in diabetes insipidus is 300 m mol/Lit.
- GFR in 8 months old child is75 ml/mn/Sq. Metre.
- In new born babies, tissue have chronaxies 10 times greater than adults.
- Nerve conduction velocity in arms is normally between 50 and 70 m/sec; whereas in leg is between 40 and 60 m/sec
- Maximum production of HCG occurs upto 12 weeks.
- Metyrapone inhibits 11-beta hydroxylase.
- Testosterone increases BMR by 15 % by increasing protein anabolism.
- Testosterone causes an increase in RBC by 20%.
- Severe stress can raise ACTH and cortisol level by 20 folds.
- Steroid hormones and T3, T4 act by enhancing specific protein synthesis and thus require 30-45 minutes for its action to start.
- Amino acid content of some polypeptide hormones
- Somatomedin (C) 70
- IGF-ll 67
- Somatostatin 14
- Dxytocin /ADH 9
- Maximum GH secretion occurs 2 hours after falling asleep.
- SIADH is characterized by low Na + in extracelluIar fluids(less than 131) meq per litre).
- ACTH1 secretion is maximum between 1 m-4am and minimum at about one hour after falling asleep.
- Upper limit to concentrate Hb in RBC is 34gm/100ml of cells.
- Till 5 years of age, bone marrow produced from all bones produces RBC.
- In normal blood reticulocyte count is less than 1%.
- Chemotaxis is very effective up to 100 microns away from an inflamed tissue.
- A neutrophil can phagocytize 5-20 bacteria before it dies while macrophages phagocytize appx. 100 bacteria.
- Evidence of Erythroblastosis fetalis is seen in 3% of second pregnancies and 10% of 3rd pregnancies while not seen in 1st pregnancy.
- Frequency of slow wave of GIT smooth muscle — 3.12/min
- Resting membrane potential of GIT smooth muscle 40 to -50 MV.
- About 80% of fibres in vagus is — Sensory (afferent) rather than efferent (Motor).
- Gastrin mechanism of gastric secretion is blocked when pH falls to 2.0.
- Potassium content of colonic secretion is — 100 in Eq/L.
- Total refractive power of eye is 59 D.
- There are 7 primary classes of olfactory stimulants.
- Cochlea has 2-3/4 turns.
- Single myofibril contains 1500 myosin filament.
- 1 myosin filament contains 200 myosin molecules.
- 13 G- actin mo are present in each revolution of the helical F-actin.
- Each myofibril contains 3000 actin filaments.
- Eye gets totally adapted to darkness in 20 minutes
- Frequencies of upto 100 Hz will not produce tetani in fast twitch muscles
- The length of sarcomere is 1.5-3.2 mm
- Aldosterene secretion in response to extracellular volume depletion of 500-l000ml will peak at 4 hours.
- Intravascular water accounts for 20% of extravascular volume
- The half life of catecholamines in circulation is 2 min
- The peak and trough of corticosteroid secretion is at 0600 and 2400 hours respectively
- Complete erythropoiesis occurs in 7 days
- Above 20% of renal plasma flow is filtered
- The catecholarnines, which are converted to VMA are 30%
- Of circulating T3, 80% is derived from de iodinated T
- Weight of pituitary is about 0.5 gm
- Half life of GH is 20-30 minutes
- Normal concentration of GH in plasma in an adults is 3 multi m u.g/ml (6 milli Hg/ml in a child)
- Vasopressin differs from oxytocin by 2 amino acids (i.e. Vasopression has arginine and phenylalanine out of 8 aminoacids whereas oxytocin has leucine and isoleucine)
- Removal of thyroid causes decrease in BMR about 40% below normal.
- Maximum rate of axonal transport is 400 mm/d
- Total bone blood flow is 200-400 mI/m
- Calcium turnover rate in bone in infants is 100% whereas in adults, it’s only 18%
- 20% increase in plasma calcium causes 2-3 times increase in rate of calcitonin secretion
- Pressure across a pulmonary capillary bed is approximately 8 mm Hg.
- The percentage oxygen saturation of mixed venous blood (Pa02 40 mm Hg is about 75%)
- P02 of renal medulla is between 10-20 mmHg
- Hypertrophic cardiomyopathy a likely when the LV wall is thicker than 13mm.
- Oxygen saturation of blood in umbilical vein is 80%.
- The mmol of H+- produced per day by body is 10100.
- The most potent endogenous hypertensive agent is angiotensin 2
- The osmoreceptors are located in the juxtaglomerular apparatus.
- Beta endorphins are released 1mm the anterior and intermediate lobe of pituitary.
- During severe exercise 02 dissociation curve of Hb shifts to right.
- Blood group antigens are sometimes found in saliva and such people are called ‘secreters.
- The most important ascending pathway for arousal response is Reticulocortical.
- The end plate potential is characterised by depolarisation.
- The major portion of body heat is lost through radiation and water evaporation.
- Destruction of pneumotaxic centre in the pons often leads to aponeustic respiration.
- If vagi are cut the rate of respiration will decrease but never ceases.
- The main driving force for glomerular filtration is the capillary pressure.
- The most important components of the sympathetic nerves are the vasoconstrictor fibres.
- The major fraction of urinary ammonia is derived from the amide nitrogen of glutamine
- The photosensitive pigment in the rods is rhodopsin has peak sensitivity to light at a wavelength of 505 nm.
- The pitch of the average male voice in conversation is about 120 Hz and that of the average female voice about 250 Hz.
- The maximum quantity % of triglyceride is contained in chylomicrons (90%).
- Of the cholesterol in the body, 93% is in cells and only 7% in the plasma, but it is the increase in the 7% in plasma that predispose to atherosclerosis.
- Thromboxane A2 is synthesized by platelets and promotes vasoconstriction and platelet aggregation.
- Prostacyalin that inhibits platelets aggregation is produced by endothelial and smooth muscle cells in the wall of blood vessels.
- Haemophilia ‘C is due to lack of factor XI deficiency.
- The total blood vol. is about 8% of body wt.
- Plasma vol. can be measured by Evants blue T-1824) or by injecting serum albumin labeled with radioactive iodine.
- Deuterium Oxide (1 is most frequently used to measure total body water (TBW).
- The resting membrane potential in neurons is – 70 mV.
- The area between 2 adjacent Z lines is called a sarcomere.
- The total tension that could be developed by all muscles in the body of an adult man is approximately 22,000 kg (nearly 25 tons).
- Bll-Magendie law states that in the spinal cord the dorsal roots are sensory & the ventral roots are motor.
- The human nervous system contains about l0 12 (1 trillion) neurons.
- The cathode ray oscilloscope (CR0) is used to measure the electrical events in living tissue.
- Most neurons in invertebrates are unmyelinated.
- In CNS of mammals, most neurons are myelinated but the cells that form the myelin are oligodendrocytes rather than Schwann cells.
- The largest known axons are found in squid (Loligo)—a mollusc (invertebrate).
- The resting membrane potential of skeletal muscle is about —90 mV. The action potential lasts 2 to 4 ms and is conducted along he muscle fibre at About 5 m/s.
- The width of the A bands is constant, whereas the Z lines move closer together when the muscle contracts and farther apart when it’s stretched.
- Myoglobin is an iron-containing pigment found in skeletal muscle. It resembles Hb but binds one rather than 4 mol of 02 permole.
- Perfluro hydrocarbons are used as artificial blood in cases of dire emergency till the desired crossed match blood is le for available for use.
- The brain is affected first in hypoxic hypoxia than others hypoxia .
- Dyspnoea is usually present where the dyspneic index is less than about 70%
- In humans the total surface area of the renal capillaries is approximately equal to the total surf ace area of the tubules, both about 12 in
- During maximal activity, the metabolic rate of nerve doubles, whereas the rate of skeletal muscle increases 100-fold.
- Nerve growth factor (NGF) is a protein growth factor that is necessary for the growth and maintenance of sympathetic neurons and some sensory neurons. NGF is a dimer made up of 2a, 2p and 2y subunits. The P subunits, each of which has a MoLwt.of l3,200 have all the nerve growth-promoting activity, the a subunits have trypsin like activity, and the subunits are serine proteases
- U “Fast” muscle fibres, primarily those concerned with fine, rapid, precise movement, have twitch durations as short as 7.5 ms, ”slow” muscle fibres, principally those involved in strong, gross, sustained movement, have twitch durations upto 100 mts. In complete tetanus there is no relaxation between summated stimuli. The tension developed is about 4 times that develop in the individual twitch contractions.
- The end organ of hearing is organ of Corti.
- The otoliths (otoconia or ear dust) range from 3 to 19 mm in length in humans are morn dense than endolyrnph.
- The speed of sound is 1450 m/s It 20°C in fresh water and is even more in salt water (Sea)
- Rapid infusion of blood or saline in anaesthetized animals sometimes produces a rise in heart rate if the initial heart rate is low. This is called as Bainbridge reflex.
- The cranial cavity normally contains a brain weighing approx. 1400 gm, 75 ml of blood and 75 ml of spinal fluid. Monro-Kellie doctrine states that at any time because brain tissue and spinal fluid are essentially incompressible, the volume of blood, spinal fluid, and brain in the cranium must be relatively constant.
- The decrease in 02 affinity of Hb when the pH of blood falls is called Bohr effect. It is closely related to the fact that deoxygenated Hb binds H+ more activity than does oxyhemoglobin.
- The pressure required to occlude blood flow with tourniquet exceeds systolic pressure by 25-50 mm Hg.
- Part of the Limbic lobe are — Septal region, Gyrus Cinguli, Para-hippocampal gyms.
- Phylogenetically the oldest part of Limbic System — Limbic lobe.
- Most developed part of Limbic System — Hippocampal formation
- Major efferent from Limbic system goes to — Mid brain reticular formation.
- Main function of Limbic system is to — Control the emotional behaviour.
- Retention of the recent memory is a function of— Limbic system.
- Reward centre is located in — Lateral & ventromedial nuclei of hypothalamus.
- Pepez circuit is concerned with — Genesis of emotion.
- Stimulation of amygdaloid nuclei causes — Chewing and Licking movements.
- The vermis of cerebellum receives afferents somatic areas of the body while the lobes are the terminus for Information arriving from motor cortex.
- Main function of cerebellum is to control movements concerned with — Control of Posture and equilibrium.
- Cerebellar nystagmus occurs due to — Damage of flocculonodular lobes.
- Sympathetic nervous system is controlled by — Posterior hypothalamic nuclei
- Parasympathetic nervous system is controlled by — Anterior nuclei and part of middle nuclei of hypothalamus.
- Satiety centre is located in — Ventromedial nucleus of hypothalamus.
- Thirst & hunger is controlled by — Lateral hypothalamic area.
- Sleep and Temperature regulation is by — Posterior pre-optic and Anterior hypothalamic area.
- Substantia Gelatinosa is formed by — Lamina II and III.
- Extramedullry tumours compress fibers of spinothalamic tract from — Sacral and lumber segments first.
- Intcamedullary tumours cause anaesthesia in Higher segments first.
- Somatic sensory area in Post anaesthesia in — Brodmann’s areas 1, 2 & 3.
- Sensations affected most by Cortical lesions — Proprioception and the touch.
- Sensation which returns earliest upon recovery is — Pain.
- Rapidly adapting touch receptors are — Meissner’s& Pacinian corpuscles.
- Slowly adapting touch receptors are — Merkel’s disk & Ruffini’s endings.
- Maximum number of touch receptors is seen in — Lips & fingers.
- Touch Sensation is predominantly carried by — type II fibers.
- Proprioception sensation is carried by—Dorsal column.
- Receptors for Temperature sensation — Free nerve endings.
- Warm receptors respond at body temperature of— 30 – 4
- Cold receptors are activated at body temperature of 10°C or below.
- Warm Sensation is carried by — C Fibres.
- Cold Sensation is carried by — A, y, C fibres.
- Percentage of sensory fibres in a pure motor fibres is — 40%
- Inhibitory neurotransmitter for spinal cord — Glycine.
- Substantia Gelatinosa contains high concentration of—Beta endorphins.
- Neurotransmitter for Nigrostriatal Pathway — Dopamine.
- Spike & dome pattern EEC is seen in — Petitmal epilepsy.
- Alpha waves in EEG has a frequency of 8-12 cps.
- Crude touch sensation is carried by — Ventral spinothalamic tract.
- Receptor for basic postural reflex is — Golgi tendon organ.
- Damage to sensory area 1 of the cerebral cortex results in — Loss of tactile & two point discrimination.
- The intensity of sensory stimuli is determined by the — Frequency of the action potential.
- In Brown. Sequard syndrome, Pain & Temperature sensation of opposite side is lost—Below the level of lesion.
- Axonal degeneration is the first change to occur in the — Distal segment of sectioned nerve.
- Pressure is received by — Pacinian corpuscles.
- Deep sleep waves in EEG are — Delta waves.
- Conduction of Type A-Alpha Fibres is —Blocked by application of pressure.
- Broca’s area is located in — Superior temporal gyrus.
- Connective tissue of nervous system — Glial Cells.
- Diameter of myelinated nerve fibres varies from — 1.20 micron.
- Active sodium ion-transport can be greatly reduced by — Cooling the cell.
- Lowest threshold for propagated action potential is seen in — Axon hillock.
- Total duration of IPSP is — 10-15 mull Sec.
- Pain from viscera arises due to Distension.
- EPSP is not affected by — Increased chloride.
- Hair fallicle receptor is supplied by —Type II fibres.
- Unilateral destruction of extrapyramidal fibres in medulla causes — Spastic paralysis contralateral to the side of lesion.
- Decerebrate rigidity is caused by — Loss of inhibition delivered to gamma efferent neurons.
- Righting reflex is lost in — Decerebrated animal.
- During spinal shock all motor and autonomic reflexes disappear.
- The majority of afferents in the basal ganglia come from —Associate cortex.
- The short term memory for verbally pooled information is — Primary memory.
- Components of reflex are — Receptor, afferent, centre, efferent, effector.
- Monosynaptic reflex is — Stretch reflex (Tendon reflex).
- Disynaptic reflex is — Crossed extension reflex.
- Polysynaptic reflex is — Withdrawal reflex.
- Asynaptic reflex is — Triple response (Axon reflex).
- Weber Fechner law — signal strength is proportional to the log of stimulus strength.
- Thalamus is the sensory relay station for all types of sensations except — Olfactory sensation.
- Main afferent of Basal ganglia is represented by —Corpus striatum.
- Festinant gait is a feature of— Parkinsonism.
- Hemiballismus of one side of the body is caused by the lesion of— Opposite subthalamus.
- Ascending reticular formation directs the attention to particular — Stored memory.
- Descending excitatory reticular formation increases the — Muscle tone.
- Mesencephalic reticular formation is responsible for — Wakefulness, alertness.
- Vagus has got following effects on heart
- Negative Chronotropic effect (Decrease in Heart rate)
- Negative Dromotropic (Reduced conductivity of the bundle)
- Negative Inotropic (Reduced force of contraction)
- Reduces the length of refractory period.
- Negative Bathmotropic (Reduced excitability) is mediated by Bainbridge reflex.
- Mary’s law states that the Heart rate and Blood pressure have inverse relationship.
- Sino-aortic nerves are also called Buffer nerves.
- BainBridge reflex (venous reflex) is characterized by reflex increase in Heart rate on venous engorgement of the right atrium right great veins.
- Cardiac index is the cardiac output/minute/square meter body surface area (n=3.3 litres).
- Pulse pressure is the difference between systolic and diastolic pressure.
- Mean arterial pressure is diastolic pressure plus one third of pulse pressure.
- The Chief seat of peripheral resistance is arterioles.
- Vasomotor centre is situated on the floor of 4th ventricle in the reticular formation.
- Most sensitive method for assessing pancreatic exocrine function is Secretin Stimulation Test.
- Pancreas is the only organ that contains Trypsinogen.
- Ascariasis can also cause acute pancreatitis.
- Serum amylase and lipase levels are usually not elevated in chronic pancreatitis.
- Constant regions are involved in biologic function of immunoglobulin molecule.
- Duodenum is the principal site of iron absorption.
- Pyrosis is other eponym of Heartburn.
- Most common complaints resulting from disorders involving the GIT include pain and alteration in bowel habit.
- Most abdundant normally secreted urinary protein is Tamm horsfall Protein.
- Hormone responsible for letting down of milk is Oxytocin.
- The anterior pituitary has the largest blood flow of any tissue in the body.
- Galactorrhoea is defined as milk production in a patient who is not post-pthum.
- Androgen appears to be essential for spermatogenesis, whereas FSH is required for spermatic maturation.
- Most common heat syndrome is Heat Exhaustion.
- Most of the heat from body is lost by Radiation.
- Cholinergic division of ANS are also called Anabolic Nervous System.
- The Chemical transmitter present at most sympathetic postganglionic endings is, Neuo nephrine
- Largest pollutants by weight is Co.
- At rest, Saliva is Hypotonic.
- Prolactin secretion is maximum during sleep.
- Intestine is the principal target or vitamin 1.25 (0H)2D.
- Milk is isotonic with plasma.
- The inferior colliculus provides the main functional link between lower and higher auditory circuits. The most common cause of sensorineural impairment is exposure to high intensity sound. The most biologically valuable and socially cherished sensation is Touch.
- Corticosterone is also known as Compound-B.
- Only apparent tract traversed through middle cerebeller peduncle is Pontocerebellar.
- Prealbumin is carrier protein for Thyroxine and vit.A
- Receptors for Osmotic pressure of plasma are cells in anterior hypothalamus.
- Hypothalamus has highest content of GABA.
- Static perimetry measures Brightness Sensitivity of Various Retinal points.
- Supraventricular tachy arrhythmias are not commonly associated with Syncope.
- Primary sleep promoting neurotransmitter is Serotonin.
- Angiotensin II is a vasoconstrictor especially on the Efferent Arterioles.
- Sitophobia is fear of eating because of subsequent abdominal discomfort.
- Part of colon where maximum fluid absorption takes place is Ascending Colon.
- Endothelium derived relaxing factor is Nitric Oxide.
- Surfactant (Dipalmitoyl lecithin) is secreted by pneumocyte II.
- Surfactant secretion is deficient in hyaline membrane disease.
- The work required to expand the lungs against its elastic forces is called compliance work.
- Residual volume provides air in the alveoli to aerate the blood between breaths.
- Helium dilution method is used to determine FRC.
- In constrictive lung disease TLC and RV both are reduced while obstructive lung diseases both the values increase markedly. FEV1 is the amount of air expired in the 1st second.
- Dead space Air—the air that goes to fill the respiratory passages with each breath (viz—Nasal passage, pharynx, trachea, bronchi).
- One respiratory unit is composed of respiratory bronchiole, alveolar ducts and alveoli.
- Respiratory membrane consists of following layer in sequence — Layer of surfactant, Alveolar epithelium, Basement membrane, Thin interstitial space, Capillary basement membrane, Endothelium. Fetal Hb. shifts 02- Hb dissociation curve to left. The chloride content of venous RBCs is greater than that of arterial cells.
- Chloride shift— HCO3- diffuse into the plasma while same quantity of C diffuse inside the REC’s in venous circulation. Haldane effect — It is the reverse of Bohr effect i.e. Binding of 02 with Fib tends to displace C02 from blood.
- Hering-Breuer reflex — The stretch receptors in bronchi and bronchioles and inhibitory signals through vagi to inspiratory centre when the lung is overinflated.
- Expiratory centre remains dormant during normal quiet respiration.
- C02, H+. affect respiration directly by acting on the respiratory centre while 02 controls respiration indirectly through peripheral chemoreceptor located in carotid and aortic bodies.
- Hydrogen ions are the only important direct stimulus for the neurons in chemosensitive area of medulla while C02 is a very potent indirect stimulus
- Change in C02 concentration has a very potent acute effect for controlling respiration while blood H+ concentration has potent effect.
- The degree of stimulation pf chemoreceptors depends on arterial P02.
- Stimulation of J receptors in the alveolar walls gives the feeling of Dyspnoea.
- Degree of cyanosis depends on quantity of deoxygenated Fib in arterial blood, rate of blood flow through skin and thickness of skin.
- Spiro meter cannot measure FRC.
- The diffusion capacity of a gas across alveolar capillary barrier is expressed as vol. per unit time per unit pressure gradient.
- If peripheral chemoreceptor responses are lost, a person is less able to adapt to life at high attitude.
- Functional residual capacity is measured by Nitrogen wash out or single breath oxygen method.
- The partial pressure of gases in the body of an individual descending below the sea increases linearly.
- Decompression syndrome is mainly characterised by paralysis.
- Hyperpnoea during exercise is because of increased C02 and impulses from motor cortex.
- Oxygen therapy is of no use in Histoxic hypoxia.
- Most potent respiratory stimulant is carbon dioxide.
- J-receptors are located in alveolar interstitium and its stimulation causes tachypnoea.
- Pulmonary arterial pressure increases in Hypoxia.
- The nephrons whose glomeruli lie close to the renal medulla are called Juxtamedullary nephrons, they extend deep into the medulla.
- Cortical nephrons—Glomeruli lie close to surface of kidney, very short loop of Henile extending into outer medulla only.
- Glomerular membrane consists of three layers— Endothelial cells, Basement membrane, Epithelial cells.
- Cl and HCO3- concentrating in glomerular filtrate is 5% higher than in plasma.
- Sympathetic stimulation of the kidneys reduces GFR by causing preferential afferent artetiolar constriction.
- Glucose and amino acid are absorbed in proximal convoluted tubules by secondary active transport or sodium Co-transport
- Descending limb of thin segment of loop of Flenle is freed permeable to water.
- Areas impermeable to water—Ascending limb of thin segment thick segment of loop of proximal half of Distal convoluted tubule.
- Areas impermeable to urea—Distal convoluted tubule & cortical portion of collecting tubules.
- Substances completely reabsorbed in PCT Glucose, proteins, amino acids, vitamins, acetoacetate.
- Substances partially absorbed in PCT- Na, K. Cl (7/8 reabsorbed in PCT).
- Substances secreted in PCT —H+, PAH (para amino hippurate), creatinine.
- Distal convoluted tubule, Cl — Is absorbed actively white positive ions follow passively (exception to the general rule).
- H+ are actively secreted in proximal tubules, distal tubules, collecting ducts.
- Hyper osmolality in the interstitum is the prerequisite for excretion of a concentrated urine.
- Urea is reabsorbed from inner meduallary collecting ducts only in presence of AD
- K+ is actively secreted in Late Distal tubules and Collecting ducts.
- Macula densa is the epithelial cells of the distal tubule that comes to contact with the arterioles.
- Juxtaglomerular cells produce renin.
- JG cells are also stimulated by low Cl content and the resultant renin angiotensin system causes predominatn efferent arterior constriction,
- Thirst center is located in lateral preoptic area of hypothalamus.
- Acidosis causes death by coma, Alkalosis by tentany or convulsions.
- Buffering power of a system is greatest when the pH is equal to pK.
- Most plentiful buffer of the body is Protein Buffer system.
- Phosphate Buffer is especially important in the tubular fluids.
- Isohydric principle — whenever any condition causes a change in H+ concentration, all the buffer systems of the body change at the same time.
- Kidneys regulate H+ concentration by increasing or decreasing HCO3- in the body fluid.
- Ammonia buffer system is active specially in chronic acidosis
- Amino acid used for treatment of Alkalosis — Lysine monohydrochloride.
- Buffer base — Anion component of the buffer system. in plasma it is HC03-, in whole blood 11C03- plus Hb ion in RBCs in entire body HCO3- plus all proteins in the body
- Davenport diagram is used to determine the type and severity of acidosis or alkalosis.
- Siggard Anderson Nomogram is used for calculating abnormalities of buffer base. U Substances inhibiting secretion of ADH —Water, Alcohol, Narcotics, Hypnotics, Anaesthetics.
- Sympathetic supply to bladder come from L2 while parasympathetic supply comes from S2S3 S4 through Nervi erigentes.
- Atonic bladder is seen in Tabes dorsalis and it is characterized by overflow dribbling.
- CSF originates as a secretion from choroid plexus in each ventricle and by all ependymal surfaces of the ventricles.
- Increasing renal blood flow increases GFR. –
- Kussmaul breathing is seen in diabetic ketoacidosis and it is not a feature of Hypercapnic acidosis.
- 3 -Globulin is not filtered through normal kidneys.
- Renal threshold for glucose is reduced in renal glycosuria.
- Ureterosigmodostomy does not cause metabolic alkalosis, Rather it causes Hyperchloremic Hypokalemic Acidosis.
- Because of the variable lengths of the nephrons, the Tubular maximum for kidney is usually less than the calculated value.
- Maximum reabsorption of glomerular filtrate occurs in I
- Renin secretion is stimulated by low sodium load on PCI’.
- Creatinine clearance represents GFR.
- Potassium reabsorption in kidneys is coupled with sodium.
- Ammonia is exchanged for sodium ions in kidney.
- A substance with renal clearance 20 times that of inulin signifies that it is synthesized in the tubules and actively secreted.
- In healthy pass down the PCT flow velocity falls.
- Sodium content of urine decreases following administration of hydrocortisone.
- In CRF (Chronic Renal Failure) anemia is usually normochromic normocytic and the treatment of choice is human erythropoietin.
- Water diuresis is seen is Diabetes insipidus.
- Post extrasystolic potentiation is due to Calcium ions.
- Vagal stimulation causes fall in blood pressure.
- Sodium retention is a factor responsible for Hypertension.
- The component of circulatory system with maximum surface area is capillaries.
- Baroreceptor stimulation cause hypotension and bradycardia.
- Maximum conduction velocity is seen in Bundle of His.
- P-R interval signifies time interval between onset of atrial contraction to onset of ventricular contraction.
- Myocardial Oxygen demand is directly proportional to Heart rate.
- Cardiac output depends on ventricular filling pressure.
- Beta 1 receptor stimulation causes tachycardia.
- Heart is most sensitive to Adrenaline.
- First reactive change to occur after haemorrhage is vasoconstriction.
- End diastolic volume determines preload.
- WPW syndrome is due to a bypass connecting atria and ventricles,
- Conduction velocity is least in AV node.
- Starling law of heart states that strength of myocardial contraction is a function of initial length of the muscle fibres.
- S.A. node is supplied by right vagus nerve, while AN. node is supplied by left vagus.
- Right bundle branch is longer than left.
- Interventricular septum is activated from left to right direction.
- The portion of ventricles excited last are the posterobasal region of left ventricle, the pulmonary conus and the uppermost portion of interventricular septum.
- Type 1 block is characterized by prolonged P-R interval in ECO.
- QRS duration is prolonged in Bundle branch block.
- Conduction velocity in bundle of His & Purkinje fibres is 1 mtr/sec.
- Excess Calcium stops the heart in systole while excess potassium stops the heart in diastole.
- Retractory period is longest in SA node.
- First heart sound indicates onset of ventricular systole.
- Protodiastolic period (0.04 sec) is the period between the onset of diastole and the closure of semiulnar valves.
- Loud SI is a feature of uncalcified Mitral Stenosis.
- Third Heart sound is caused by the sudden rush of atrial blood into the ventricles when the A-V valves open.
- Fourth heart sound is caused by the rapid rush of blood due to atrial contraction.
- Wenekebach phenomenon is characterized by progressive prolongation of P-R interval followed by a drop beat.
- Troponin T binds to Tropomyosin; Troponin C binds is calcium and Troponin I inhibits the F-actin and myosin interaction,
- Most important function of progesterone is to promote secretory changes in endometrium.
- Progesterone completes breast development by promoting alveolar and lobular development.
- Progesterone competes with aldosterone and thus causes Na & H20 excretion.
- Progesterone is the hormone for maintenance of pregnancy.
- Progesterone inhibits ovulation.
- Progesterone decreases membrane excitability by increasing resting membrane potential
- Theca interna produces estrogen while Granulosa cells produce Progesterone.
- The hormone used for treating osteoporosis in old age — Testosterone.
- Aldosterone causes retention of Na+ & Cl-, H20.
- Aldosterone acts on distal tubuks in kidney, duct system of salivary glands, intestine.
- Aldosterone helps in maintaining excitability by preventing Hypokalaemia and Hyperpolarization.
- Glucocorticoids reduces cellular protein of all parts of the body except liver.
- Glucocorticoids increase Gluconeogenesis in liver.
- Glucocorticoids mobilize fatty acids from adipose tissues, thus increase plasma FFA.
- Glucocorticoids increase pepsin and gastric acid secretion.
- Glucocorticoids facilitate water insoluble lipid absorption while prevent calcium re absorption (Because it is antagonistic to Vit.D).
- Glucocorticoids causes Eosinopenia, Lymphocytopenia.
- Miscible pool of calcium ion is the Calcium present in Periosteal space (1% of total).
- Largest endocrine gland in human —Thyroid.
- Wolff Chalkoff effect — Above a critical level, intrathyroidal 1 inhibits organic binding.
- Phenytoin. Salicylates compete with fl & T4 for binding to TBG.
- Chronic hypothyroidism causes atherosclerosis.
- T4 causes breakdown of hyaluronic acid therapy increases urinary hexodamines.
- Thyroid hormone is necessary for conversion of (3 carotene to Vitamin A.
- Thyroid hormone decreases P04 and calcium contentof body but increases Mg.
- Hypothyroidism causes constipation.
- Thyroid hormone may cause eruthroid hyperplasia of Bone marrow.
- Extreme somnolence is a feature of hypothyroidism.
- Coupling reaction is inhibited by propyithiouracil, methimazole, carbimazole.
- Iodide trapping is inhibited by thiocyanate, perchiorate & nitrates.
- Inhibitors of insulin secretion — Epinephrine, insulin, starvation, hypoxia, vagotomy, serotonin.
- Stimulators of insulin secretion — Glucose, A.A., Ketones, ATP, AMP.
- Hormones derivd from cholesterol — Glucocorticoids, Mineralocorticoids, Estrogens. Progestins, Androgens, Caicitriol.
- Hormones requiring cAMP as second messenger — Ant, pit. hormones (except OH), ADH, PTH, Calcitonin, Glucagon.
- Hormones requiring Ca or phosphatidylinositol as 2nd messenger— ADH, TRH, LHRH, Angiotensin II, Acetylcholine specific protein.
- Hormones bound to Globulins in plasma — Hydrocortisone, Estrogen, Testosterone, T3,T4.
- Down regulation of receptors is seen with Insulin, Glucagon, GH, TRH, LH, FSH, Catecholamines.
- Acidophil cells of Anterior pituitary produce Basophil cells produces — OH, Prolactin (PRL) — FSH, LH, TSH, ACTH.
- Growth promoting action of GH is mediated through Somatomedin-C which is synthesized in Liver, Muscle, Kidney.
- Somatomedin causes deposititionof chondroitin sulphate and collagen.
- GH can cause fatty liver and ketoacidosis by excessive mobilization of fat from adipose tissues.
- Anteriorior pituitory hormones with diabetogenic effect—GM, ACTH, TSH, PRL.
- GH enhances transport of aminoacids into muscle cells.
- Potent stimulus of GM secretion is hypoglycemia under acute condition while protein deficiency in chronic conditions.
- Arginine is the potent stimulus for GH secretion.
- Somatostatin is produced from D cells of Pancreas and Hypothalamus. It inhibits the secretion of GH,Insulin,Glucagon,TSH FSH.ACTH.
- Slow wave is generated in the— Longitudinal muscle layer.
- Depolarisation of CIT smooth muscle occurs by — Stretch, Acetyleholine Parasympathetic stimulation.
- Auerbach’s plexus lies between longitudinal and circular muscular layers and controls — The movement of CIT.
- Meissner’s plexus lies in the — Submucosa and controls secretion
- Small intestine is poorly supplied by — Parasympathetic system.
- Vagal stimulus for peristalsis is —Distension.
- Chymotrypsinogen is activated into chymotrypsirin by — Trypsin.
- Most potent stimulus for bile secretion is — Bite salt.
- Secretin does not increase — Gastric secretion.
- Saliva contains highest concentration — K-i-.
- Richest source of Vit. C in body —Adrenal cortex.
- Gastric phase of gastric secretion is — Hormone mediated.
- Vagal stimulation causes— Constriction of intestinal musculature and increase in intestinal secretion.
- Secretin causes pancreatic secretion poor in enzymes but rich in — Water and bicarbonae.
- Cephalic phase of gastric secretion is mediated by — Parasympathetic nervous system.
- Most potent stimulus for secretin is — Hormone mediated.
- Electrolyte absorption can occur also in — Colon.
- Best stimulus for CCK secretion is — Fat.
- Ga.cthc emptying is not affected by — Osmolality of contents in duodenum.
- Pepsinogen is activated by —Acidic pM.
- Vagal stimulation does not affect — Parotid secretion.
- Saliva contains — Thiocyanate ions also.
- Intrinsic factor is secreted by — Oxyntic cells of stomach.
- Vagal stimulation increases — Gastrin secretion.
- Intestinal phase of gastric secretion is mediated by— Hormones and reflex both.
- The secretion from stomach during interdigestive period contains mostly — Mucus.
- Brunner’s gland in intestine secrete — Mucus.
- Stomach can absorb—Alcohol and Aspirin.
- Vomiting centre is situated in — Medualla near tractus solitarius, close to the dorsal motor nucleus of vagus.
- Constituents parts of ciliary body are Ordicularis cillaris, Ciliary process, Ciliaris rnusc e.
- Lens is rich in Cysteine and Glutathione.
- Events taking place in accommodation are increased curvature of lens, constriction of pupils, convergence of two optical axes.
- Sniffing is a semi reflex phenomenon towards an attractive odour.
- Peripheral end organ for olfaction are olfactory stimulants.
- Peripheral end organ for olfaction are olfactory cells.
- Primary modalities of taste followed by bitter after taste.
- Coefficient of 1 is taken for 1 (Sour), Quinine (Bitter), Sucrose (Sweet), NaCI (Salt).
- Sweet sensation is perceived maximum at Tip, Salt on the dorsum anteriorly, Sour at the sides, Bitter at the posterior part Of tongue.
- The hair cells of semicircular canals are stimulated by cessation or rotation.
- Round window separates scala tympani from the middle ear.
- Stapes is attached to the oval window.
- Loud sounds cause a reflex dampening of the movements of the auditory ossicles.
- Endolymph baths the organ of corti and the copulae of semicircular canals.
- The Organ of corti is situated on Tectorial membrane.
- Ionic milieu of endolymph is maintained by stria vascularis.
- Localisation of sound source is possible if it is in front, behind or side of the head.
- Semicircular canal is stimulated by rotational acceleration
- Endolymph potassium concentration is closer to that of intracellular fluids.
- Utricle in inner ear acts as gravity receptor.
- Regular interruption in the sheath in the case of Myelinated fibres are called nodes of Ranvier.
- White matter contains greater concentration of Myelin.
- A nerve impulse is the propagated action potential.
- Saltatory conduction velocity is proportional to the diameter of nerve fibres.
- Miniature end plate potential at neuromuscular junction is due to leakage of small quantities of Acetyl choline from Vesicles.
- The equilibrium potential (E) for any ion is the potential that the membrane will approach if the membrane becomes freely permeable to the ion.
- The stimulus necessary to cause local contraction of skeletal muscle is minimal at !z! line.
- Transmembrane potential moves towards Equilibrium potential for sodium in generation of initial phase of action potential.
- Curare blocks neuromuscular junction by decreasing the amplitude of end plate potential.
- Myosin is present throughout the A band.
- Head of Myosin is strongly negative and exhibits ATPase activity.
- There is no movement in the myosin filament during muscle contraction.
- F-actin is the double helical filament made up to globular actin (G-actin).
- One molecule of ADP is attached to each molecule of G. Actjn.
- Actin filaments slide over the myosin filament during muscle contraction.
- Tropomyosin covers the active sites of actin.
- The extended body parts of warm blooded species are relatively shorter in the colder regions of a species range than in the warmer is called Allen rule.
- In hemophilia, only women transmit the condition, only men inherit is Lossen rule
- When complete fusion occurs and the sensation is uniform, the intensity is same as
- would occur were the same amount of light spread uniformly over the disc is Talbot’s law
- In a lateral cerebral lesion, the head is turned toward the side involved is Prevost’s law
- A muscle situated above an inflammed membrane is often affected with paralysis is Stokes law
- An after sensation of colour is Me Collough effect
- The disharmonious development of gray and white matter of brain, the gray being in excess is known as Mierzejewski effect
- Smooth muscle contraction begins approximately 150 ms after action potential
- The body weight of an adult ought to be as many kg as his body length in centimeters exceeds 100 is Ometelet’s rule
- Increased perfusion pressure and subsequent stretch of vascular smooth muscle contraction and increased resistance, which returns to normal inspite of elevated perfusion pressure is Bayliss effect.
- The ideal systolic pressure for an adult is the figure represented by 100 plus half the age in years is called Rolleston rule
- A granular layer of each transparent lateral disk of a muscle fibrile is Floegels layer
- The loss or destruction of elements in the organic world is apt to be followed by overproduction of such elements in the reparative process is Weigert’s law
- The relation between intensity and area of illumination i.e. intensity times area equals constant is Ricco’s law
- The law that regeneration is more complete in younger individuals than in older ones is Spallanzani’s law
- Calmadulin is a protein with which calcium binds on entering the cell.
- One of the specific function of calmodulin is to activate the myosinkinase, which then acts directly on the myosin of smooth muscle to cause contraction
- Protein kinase acts as a third messenger
- A ‘standard curve’ is obtained by performing the procedure with standard solution of untagged hormone at several different concentration level.
- Chromophobe cells of Ant, pituitary secrete ACTH whereas chromophil cells secrete GH and prolactin (acidophilic cells) and TSH, FSH and LH (basophilic cells)
- Hemming bodies are found in posterior pituitary
- Pituicyte cells (in post, pituitary) do not take part in secretion of hormones and act as supporting cells
- Interneurons are not functioning in sketch reflex
- Prosophenosia refers to inability to recognize faces
- Ansa lenticularis connect all efferents of globus pailidus and putamen
- 1,11 and Gamma fibres (not alpha fibre) innervate the muscle spindal
- The transverse marks on the axon of a medullated nerve fibres, rendered visible by silver nitrate are Frammann’s lines
- Koniocortex refers to agranular cortex
- A line of junction between ectoderm and endoderm is Ectental line
- Microscopic broken or-scalariform lines at the junction of cardiac muscle are Ebertb lines
- Brodel’s white line is found in kidney
- Sattler’s layer is found in choroid
- Zeissels layer is found in stomach
- An aluminium band for temporally occluding large blood vessel in order to check condition of the collateral circulation is called M band
- The broad bands alternating with Z bands in the fibrils of striated muscles are Brucke’s lines
- M-band (narrow dark band in the centre of H-band of sarcomere) is also called Hensen’s line
- Dobie layer is also called Z-band
- Somatostatin inhibits secretion of gastrin, secretin, VIP and GIP
- Secretin is a polypeptide with 27 aminoacids and a fall of pH below 4.5 causes prompt increase in its secretion
- Insulin was first discovered by Banting and Best in 1921 extracted from pancreas.
- F-cells (P-cells) in pancreas secrete pancreatic polypeptide. Alpha cells secrete glucagon, Beta cells insulin and delta cells-gastrin and somatostatin.
- Thyroid hormones have prominent effects on bone resorption and formation
- Insulin has prominent effect on bone formation
- Interleukin -1 has prominent effect on bone resorption
- The deposition of bones at points of compression and stress has been suggested to be causes by a piezoelectric effect
- T is oxygen deficiency at tissue level
- Daily urine output more than 2L/d is suggestive of polyuria
- The ratio of T3 and T4 in circulation is 1:100
- Arterioles are responsible for 50% of peripheral vascular resistance.
- Conversion of carotlenes to vitamin A is facilitated by thyroxine.
- Transmural pressure in a vessel (pt equals wall tension in vessel (T) + radius (R) of vessel
- Capillaries have a surface area of approximately 300 sq.m
- The conversion of the intermittent blood flow in the aortic arch to a smooth blood flow is Wind Kessel effect
- Absence of gravity causes 4- Blood volume, 4- circulating T cells and osteoporosis
- In kidneys, medullary rays are groups of collecting tubules
- Movement of malleus and incus occurs at 600 Hz
- Exercise produces T HDL cholesterol
- Hemolytic anemia of exercise is mainly due to damage to REC’s
- With exercise, skin blood flow rises by 2%
- Cyanosis is detectable when arterial oxygen saturation falls below 75% corresponding to P02 of 40 mmHg.
- Mechanical efficiency is the ratio between amount of work performed and total average energy output of the body. For athletes,it is 25-30% (approx) and for untrained man = 20% (approx)
- The height of hyperpnea at which dyspnoea appears is called Dyspnoea point U 250m1 of oxygen enters the body per mm and 200 ml of C02 is excreted
- The fraction of blood that gives up its oxygen as it passes through the tissue capillaries is called the Utilization coefficient . Normally it is about 0.25.
- Receptors for which ligands are still unidentified are called Orphan receptors.
- Because of nervousnes, about 30% of hypertensive patients have higher BPin the doctor’s office than during normal daytime activity called white coat Hypertension.
- A common cause of paraoxysmal arrythmias is a defect in conduction that permits a wave of excitation to propagate continuously within a closed circuit called Circus movement
- Pulmonary alveolar macrophages form called ‘Dust cells”
- When the gastric acid secretion is elevated after a meal, sufficient 1 may be secreted to raise the p of the systemic blood and make the urine alkaline. It is called Postprandial Alkaline Tide.
- Incomplete tetanus is called clonus.
- Chronaxie of skeletal muscle is shorter than that of cardiac and smooth muscles.
- Cold lengthens chronaxie, whereas vagal stimulation shortens chronaxie.
- Testes does not produce fructose.
- FSH level is high in post menopausal women.
- Pigmentation is not a feature of panhypopituitarism.
- Fetal lung maturation depends on increased fetal Cortisol just before birth.
- LH is concerned with follicle maturation and ovulation.
- Testosterone is synthesized from pregnanolone.
- Alloxan causes diabetes.
- ADH acts on Collecting tubules.
- Adrenalin does not penetrate the cell membrane.
- TRH stimulated TSH and prolactin.
- Thyroxine has no role in response to trauma.
- HPL (Human placental lactogen) acts as GH for fetus.
- Chief metabolite of Estrogen in post menopusal women is sterone.
- Anabolic action on protein metabolism is mediated by Testosterone.
- Target Cellular organ for estrogen is nucleus.
- Menopausal hot flushes is due to LH surge.
- Increase in insulin receptor is seen in starvation.
- Male sex hormone is secreted mainly by Interstitial cells of Leydig.
- Development of male sex organ in fetal life depends on testosterone produced under the influence of HCG.
- Testosterone circulates in Combination with Gonadal steroid binding globulin.
- Estrogen increases the secretion and ciliary beating in fallopian tubes.
- Estrogen changes the cuboidal lining of vagina to stratified.
- Estrogen changes the break down of glycogen into lactate in vagina.
Be the first to comment