Physiology flashcards for NEET PG

Inulin: freely filtered, not reabsorbed or secreted.

Memory hook: Creatinine is the practical stand-in.

Isovolumetric contraction.

Memory hook: Pressure up, volume fixed.

Raised 2,3-BPG, CO₂, H⁺ (low pH) and temperature.

Memory hook: CADET face Right: CO₂, Acid, 2,3-DPG, Exercise, Temperature.

AV node: the delay lets the atria empty before the ventricles contract.

Memory hook: Purkinje is the fastest.

H⁺ in the brain extracellular fluid, produced from CO₂.

Memory hook: Peripheral ones are the ones that sense low O₂.

Capillary hydrostatic pressure and interstitial oncotic pressure. Opposing: plasma oncotic and interstitial hydrostatic pressure.

Memory hook: Oedema: more push out or less pull in.

Juxtaglomerular cells release renin; angiotensin II and aldosterone then raise blood pressure and sodium retention.

Memory hook: Renin starts the cascade.

About 125 mL/min, or around 180 litres a day.

Memory hook: Falls about 1 mL/min per year after 40.

The thick ascending limb of the loop of Henle.

Memory hook: The diluting segment.

Type II pneumocytes; it reduces alveolar surface tension and prevents collapse.

Memory hook: Premature babies lack it, giving RDS.

Facilitated diffusion via GLUT carriers, down its concentration gradient without ATP.

Memory hook: GLUT4 is the insulin-dependent one.

3 Na⁺ out and 2 K⁺ in, using one ATP.

Memory hook: 3 out, 2 in.

K⁺ (about −90 mV), because the resting membrane is most permeable to K⁺.

Memory hook: Rest is a potassium state.

The equilibrium potential of a single ion across a membrane.

Memory hook: One ion: Nernst. Many ions: Goldman.

Secondary active transport: glucose is co-transported with Na⁺ down the sodium gradient.

Memory hook: Pump makes the gradient, SGLT uses it.

Intracellular fluid; extracellular fluid holds one-third, of which plasma is about one-quarter.

Memory hook: 2/3 inside, 1/3 outside.

Inulin (or sucrose, mannitol); plasma volume is measured with Evans blue or radio-iodinated albumin.

Memory hook: Evans blue stays in plasma.

Erythropoietin, from peritubular interstitial cells of the kidney, driven by hypoxia.

Memory hook: Hypoxia, not anaemia itself, is the signal.

About 120 days.

Memory hook: Four months.

Factors II, VII, IX and X, plus proteins C and S.

Memory hook: 1972 and C, S.

PT for extrinsic (factor VII); aPTT for intrinsic (VIII, IX, XI, XII).

Memory hook: PT = Prothrombin, extrinsic; warfarin monitor.

IgG, via the neonatal Fc receptor.

Memory hook: G for Gestation.

IgM.

Memory hook: M for Mounts first.

Antigen-presenting cells such as dendritic cells, macrophages and B cells; helper T cells carry CD4.

Memory hook: CD4 x MHC II = 8; CD8 x MHC I = 8.

An Rh-negative mother carrying an Rh-positive fetus forms anti-D IgG that crosses the placenta in later pregnancies.

Memory hook: Anti-D prophylaxis prevents sensitisation.

Na⁺ influx through voltage-gated sodium channels; repolarisation is by K⁺ efflux.

Memory hook: Na in, K out.

A-alpha fibres (large, myelinated), about 70 to 120 m/s.

Memory hook: Big and myelinated is fast.

Pressure hits large A fibres first; local anaesthetics block small fibres before large ones.

Memory hook: Pressure: large first. LA: small first.

Depolarisation of T tubules changes the DHP receptor, which opens the ryanodine receptor.

Memory hook: DHP talks to RyR.

Troponin C, which moves tropomyosin and exposes myosin-binding sites on actin.

Memory hook: Smooth muscle uses calmodulin.

The I band and H zone shorten; the A band stays constant.

Memory hook: A stays, I and H go.

Nicotinic (Nm) receptor; in myasthenia, autoantibodies against it reduce receptor number.

Memory hook: Treat with anticholinesterases.

About 55 to 70 percent: stroke volume divided by end-diastolic volume.

Memory hook: EF = SV / EDV.

Stroke volume multiplied by heart rate (about 5 L/min at rest).

Memory hook: CO = SV x HR.

Within limits, greater end-diastolic stretch gives a stronger contraction and larger stroke volume.

Memory hook: More fill, more force.

The T wave; atrial depolarisation is the P wave and ventricular depolarisation the QRS.

Memory hook: P, QRS, T.

Closure of the mitral and tricuspid valves at the start of ventricular systole.

Memory hook: S1 = AV valves close, 'lub'.

Diastolic pressure plus one-third of pulse pressure.

Memory hook: MAP = DBP + PP/3.

Stretch receptors in the carotid sinus (via IX) and aortic arch (via X); a fall in pressure raises heart rate and tone.

Memory hook: Carotid sinus: glossopharyngeal.

Residual volume, and hence FRC and TLC; use helium dilution or body plethysmography.

Memory hook: Air that never leaves.

Inspiratory reserve volume + tidal volume + expiratory reserve volume.

Memory hook: VC = IRV + TV + ERV.

Reduced FVC with a normal or raised FEV1/FVC ratio.

Memory hook: Small lungs, ratio kept.

Reduced FEV1/FVC ratio (below 0.7), with increased residual volume.

Memory hook: Air trapped.

The apex; perfusion falls off faster than ventilation, so V/Q is higher at the apex and lower at the base.

Memory hook: Apex: high V/Q, TB likes it.

Medulla; it drives inspiration. The ventral group handles forced expiration.

Memory hook: Dorsal = Draws air in.

Upper pons; it limits inspiration and so raises respiratory rate.

Memory hook: Pneumotaxic: switches off inspiration.

Proximal convoluted tubule, about 65 percent, isosmotically.

Memory hook: Two-thirds in the PCT.

Principal cells of the late distal tubule and collecting duct; increases Na⁺ reabsorption and K⁺ secretion.

Memory hook: Salt in, potassium out.

Collecting duct principal cells via V2 receptors, inserting aquaporin-2 channels.

Memory hook: V1 vasoconstricts; V2 retains water.

The loop of Henle, with its ascending limb pumping out salt; the vasa recta preserves the gradient.

Memory hook: Multiplier in the loop, exchanger in the vasa recta.

pH = 6.1 + log ([HCO₃⁻] / (0.03 x PCO₂)).

Memory hook: 6.1 is the pK of the bicarbonate system.

Low pH, low HCO₃⁻, and respiratory compensation lowers PCO₂ (Kussmaul breathing).

Memory hook: Lungs blow off CO₂.

Parietal (oxyntic) cells of the stomach.

Memory hook: B12 absorption needs intrinsic factor.

Chief (peptic) cells; it is activated to pepsin by acid.

Memory hook: Chief = pepsinogen.

Cholecystokinin from I cells of the duodenum, released by fat and amino acids.

Memory hook: CCK: contracts the gallbladder.

Secretin from S cells of the duodenum, released by acid.

Memory hook: Secretin neutralises acid.

Motilin, released during fasting at intervals of about 90 minutes.

Memory hook: Housekeeper wave.

Terminal ileum, by active transport; this enterohepatic circulation recycles about 95 percent.

Memory hook: Ileal disease causes bile salt loss.

Terminal ileum, as the B12–intrinsic factor complex.

Memory hook: Iron is duodenum.

Prolactin.

Memory hook: Only anterior pituitary hormone mainly under inhibition.

ADH and oxytocin; both are synthesised in the hypothalamus (supraoptic and paraventricular nuclei).

Memory hook: Stored, not made, in the posterior pituitary.

5'-deiodinase in peripheral tissues.

Memory hook: T3 is the active form.

Calcitonin from the parafollicular C cells of the thyroid.

Memory hook: Calcitonin: 'tones down' calcium.

Raises serum calcium and lowers phosphate, via bone resorption, renal calcium reabsorption, phosphate excretion and activating vitamin D.

Memory hook: Phosphate goes down.

Beta, alpha and delta cells respectively.

Memory hook: Alpha = A for glucagon (Anti-insulin).

Zona fasciculata; the glomerulosa makes aldosterone and the reticularis androgens.

Memory hook: GFR = salt, sugar, sex.

The mid-cycle LH surge, triggered by high oestrogen positive feedback.

Memory hook: Oestrogen peak, then LH peak.

hCG from the syncytiotrophoblast, until the placenta takes over progesterone production in the first trimester.

Memory hook: hCG rescues the corpus luteum.

Leydig cells make testosterone (under LH); Sertoli cells support sperm (under FSH) and secrete inhibin.

Memory hook: L for LH-Leydig.

The luteal (secretory) phase, about 14 days; the follicular phase varies.

Memory hook: Ovulation is 14 days before menses.

Progesterone, which raises temperature by about 0.5 °C.

Memory hook: Progesterone = pro-gestational warmth.

Milk ejection (let-down), via contraction of myoepithelial cells; suckling triggers it by a neuroendocrine reflex.

Memory hook: Prolactin makes milk; oxytocin ejects it.

Inhibin, from Sertoli cells in males and granulosa cells in females.

Memory hook: Inhibin inhibits FSH.

Muscle spindle: length and rate of stretch (Ia, II afferents); Golgi tendon organ: tension (Ib afferents).

Memory hook: Spindle: length. GTO: tension.

Rods, which contain rhodopsin and are absent from the fovea; cones serve colour and acuity.

Memory hook: Rods: night, periphery.

Optic chiasm, as in a pituitary tumour, affecting crossing nasal retinal fibres.

Memory hook: Chiasm: both temporal.

On the basilar membrane within the cochlea; hair cells (inner hair cells transmit most signals).

Memory hook: Outer hair cells amplify.

The hypothalamus; the preoptic anterior area senses heat and the posterior area drives heat conservation.

Memory hook: Anterior cools, posterior warms.