Masters in Medical Physiology

Examine the SA node’s pacemaker potential from -60 to -40 mV, driven by funny current and T-type calcium influx, with depolarization via L-type calcium and autonomic regulation.

Explore vascular physiology, detailing the aorta's wind causal effect and elastic recoil, capillary exchange driven by hydrostatic and colloidal osmotic pressures, and venous lymphatic return.

Learn preload as end-diastolic volume and its dependence on venous return, venous constriction, and vasodilation, and afterload as aortic pressure set by total peripheral vascular resistance and arteriolar tone.

Learn how left ventricular pressure-volume loops map pressure and volume changes, including end diastolic and end systolic volumes, stroke volume, and conditions like aortic stenosis and regurgitation.

Kussmaul sign is the lack of a normal decrease or an actual increase in jugular venous pressure during inspiration, indicating right ventricular dysfunction seen in constrictive pericarditis and restrictive cardiomyopathy.

Explore jugular venous pressure waveforms - a, c, x, v, y waves - linking atrial contraction and atrial/ventricular events to conditions like tricuspid stenosis, pulmonic stenosis, tricuspid regurgitation, atrial fibrillation, and constrictive pericarditis.

Explore hemodynamics by analyzing laminar blood flow and Reynolds number, and apply Higgins (Poiseuille) formula showing blood flow depends on pressure difference and radius, inversely on length and viscosity.

Understand how central venous pressure, or right atrial pressure, rises in right- and left heart failure, tamponade, constrictive pericarditis, tricuspid disease, pulmonary hypertension or embolism, and falls with venous return.

Explore cardiac reflexes including Cushing's bradycardia with intracranial pressure, Bainbridge's tachycardia from increased venous return, Bezold-Jarisch bradycardia during myocardial infarction, and oculo-cardiac reflex effects from eye compression.

Explore the cardiac cycle’s phases—isovolumetric contraction and rapid/slow ejection, diastole’s relaxation and filling—plus S1, S2, S3, S4, ejection click, opening snap, preload, and end diastolic/end systolic volumes.

Learn how mean arterial pressure and pulse pressure shape blood pressure, and how baroreceptors in the carotid sinus and aortic arch regulate it via the medulla, with posture effects.

Describe the normal pulse waveform with systolic rise, diastolic drop, and the dicrotic notch, then summarize key abnormal pulses: dicrotic, bounding, pulsus alternans, paradoxus, parvus et tardus, and water hammer.

Understand the heart's nodal and muscular tissues, the action potential pathway from SA node to Purkinje fibers, and the spectrum of AV blocks (first to third degree) with AV dissociation.

Survey the Vaughan Williams classes of antiarrhythmic drugs: sodium, potassium, beta and calcium channel blockers; covering indications like wpw syndrome, post-mi ventricular tachycardia, and torsades de pointes.

The hypothalamus serves as the master regulator of the endocrine system. It coordinates anterior and posterior pituitary function through releasing and inhibitory hormones, linking thyroid, adrenal, and gonadal axes.

Explore pituitary stalk damage and Sheehan syndrome, prolactinomas, and their effects on hypothalamus-pituitary axis, including galactorrhea, amenorrhea, and bitemporal hemianopia.

Oxytocin and vasopressin are posterior pituitary hormones produced in hypothalamic nuclei and released via hypothalamo hypophyseal tracts; oxytocin triggers labor and milk ejection, vasopressin regulates water balance and vascular tone.

Explains how prolactinomas compress the optic chiasm to cause bitemporal hemianopsia, maps the six-layer lateral geniculate body and its magnocellular and parvocellular pathways, and outlines the pupillary light reflex.

Explore growth hormone physiology: hypothalamic control of the anterior pituitary, direct bone growth, and indirect actions via liver-derived IGF-1.

Explore how thyroid hormones are synthesized in follicular cells: iodide trapping, thyroglobulin, oxidation, organification, and coupling yield T3 and T4 stored in colloid, with calcitonin from parafollicular cells.

Explore how thyroid hormones T3 and T4 regulate heart rate, metabolism, adipose and protein breakdown, and CNS and bone development; and contrast hypothyroidism and hyperthyroidism with clinical features.

Explore how cortisol, produced by the adrenal cortex under ACTH, acts as a glucocorticoid and stress hormone; excess causes Cushing's syndrome with hyperglycemia, moon face, buffalo hump, and centripetal obesity.

Congenital adrenal hyperplasia is an autosomal recessive disorder causing cortisol and aldosterone deficiency with excess adrenal androgens, marked by elevated 17-hydroxyprogesterone and ambiguous genitalia in females.

This lecture explains calcium homeostasis through parathyroid hormone, calcitriol, and calcitonin, detailing how PTH and vitamin D raise blood calcium, while calcitonin lowers it.

Learn the pancreas' endocrine and exocrine roles, including insulin, glucagon, somatostatin, ghrelin, c-peptide as endogenous insulin marker, amylin, and amylin analog pramlintide in diabetes.

Pancreatic beta cells sense elevated glucose via Glut2 transport, raise ATP, close ATP-sensitive potassium channels, depolarize, open calcium channels, and exocytose insulin-containing granules. Sulfonylureas block ATP-sensitive potassium channels, boosting insulin.

Examine regulation of insulin release by glucose, glucagon, arginine and leucine, long-chain fatty acids, and parasympathetic activation, and outline diabetic ketoacidosis pathogenesis and its ketone-induced acidosis.

Insulin lowers blood glucose by promoting Glut4-mediated glucose uptake in skeletal muscle and adipocytes. It enhances glycogenesis and glycolysis while inhibiting glycogenolysis, gluconeogenesis, lipolysis, and ketogenic processes.

Explore the four layers of the gastrointestinal tract, the submucosal Meissner's plexus and the myenteric plexus driving secretion and motility, and how neural crest migration defects cause Ursprung disease.

Explore the spectrum of gastrointestinal secretions, including saliva, gastric, pancreatic, bile, and intestinal fluids; volume and reabsorption, saliva enzymes like salivary amylase and lingual lipase, Brunner's glands, and neural regulation.

Describe goblet cell mucus stained with alcian blue and Paneth and M cells; outline motilin and ghrelin roles in gastrointestinal motility via interstitial cells of Cajal.

Explore gastric glands, including surface and neck mucous cells, parietal and chief cells, and their products pepsinogen, gastric lipase, acid, intrinsic factor, and gastrin.

Explain digestion in the stomach and pernicious anemia, where autoantibodies attack parietal cells reducing hcl and intrinsic factor, causing B12 and iron deficiencies and megaloblastic anemia.

Identify absorptive sites for iron (duodenum), vitamin B9 (jejunum), B12 (terminal ileum); summarize iron regulation via DMT1, ferroportin, hepcidin, and hephaestin, including parasite-induced malabsorption.

Summarize pancreatic exocrine enzymes and zymogens, such as trypsinogen and chymotrypsinogen, and how secretin and cholecystokinin regulate bicarbonate secretion, bile release, gallbladder contraction, and gastric emptying.

Describe how the liver produces about 500 ml of bile daily, comprising bile acids, bile salts, bilirubin and biliverdin pigments, cholesterol, water, and electrolytes, to emulsify fats.

Explore male reproductive physiology, including hypothalamic control of FSH and LH, Leydig and Sertoli cell roles, spermatogenesis, and epididymal maturation.

Explore how estrogens and androgens regulate development and sexual traits, derived from cholesterol and bound to sex hormone binding globulin. Learn about GnRH, FSH, LH, and pulsatile versus continuous signaling.

Trace how GnRH regulates FSH and LH to drive Sertoli and Leydig cell function, producing testosterone and DHT with implications for puberty, fertility, BPH, and androgen insensitivity.

Demonstrates the two-cell, two-hormone estrogen synthesis in the ovary, with LH/FSH acting on theca and granulosa cells to produce estradiol, plus progesterone, pregnancy, menopause, and contraception concepts.

Explore gametogenesis, detailing spermatogenesis from spermatogonia to spermiogenesis and oogenesis from oogonia to fertilization. Understand diploid to haploid transitions, meiosis stages, and the roles of Sertoli and Leydig cells.