Pulse of Physiology

Explains the stages of labor and the hormonal regulation of childbirth and breastfeeding . Discusses the role of oxytocin and prostaglandins in labor, and prolactin and oxytocin in milk production and ejection.

Follows the journey from sperm-egg fusion through blastocyst formation and implantation . Highlights the role of hCG , the formation of the placenta , and key hormones like progesterone, estrogen, and hCG in sustaining pregnancy.

Covers the menstrual, proliferative, and secretory phases of the uterine cycle. Describes how estrogen and progesterone prepare the endometrium for implantation and how their withdrawal leads to menstruation when pregnancy does not occur.

Explores the development and maturation of ovarian follicles through the follicular and luteal phases . Emphasizes the roles of FSH, LH, estrogen, progesterone, and inhibin , and explains how hormonal feedback regulates ovulation and corpus luteum function.

Details the process of sperm development , distinguishing between spermatogenesis and spermiogenesis . Explains the roles of Sertoli and Leydig cells and describes how FSH, LH, testosterone, and inhibin regulate sperm production through hormonal feedback loops.

Provides an introduction to the male and female reproductive systems , outlines homologous structures , and summarizes the functions of key reproductive hormones, including GnRH, FSH, LH, testosterone, estrogen, progesterone, and inhibin .

Focuses on how the enteric nervous system (ENS), autonomic input, and digestive hormones like gastrin, secretin, and CCK regulate motility and secretion during the cephalic, gastric, and intestinal phases of digestion.

Breaks down the chemical digestion of carbohydrates, proteins, and fats. Introduces digestive enzymes and their sources , the role of hydrochloric acid , and how bile salts aid fat digestion . Wraps up with the role of the gut microbiome in digestion and health.

Explores how food moves through the GI tract using peristalsis, segmentation, mixing waves, and mass movement . Discusses how factors like chyme composition and volume influence gastric emptying, and how neural and hormonal signals regulate motility.

Covers the six major functions of the digestive system— ingestion, propulsion, mechanical digestion, chemical digestion, absorption, and defecation . Differentiates between GI tract structures and accessory organs , and explains how food is broken down and moved through the digestive system.

Apply your knowledge to diagnose and interpret acid-base imbalances using arterial blood gas (ABG) values . Differentiate between respiratory and metabolic acidosis or alkalosis , and determine whether compensation has occurred.

Understand how the respiratory and urinary systems compensate for acid-base disturbances . Learn how the body responds to respiratory or metabolic acidosis and alkalosis , and the time course of each compensatory mechanism.

Learn the basics of pH regulation , including the roles of acids, bases, and buffers . Get introduced to the bicarbonate, phosphate, and protein buffer systems , and why maintaining a stable pH is essential for enzyme and cell function.

Discover how the cardiovascular, endocrine, and urinary systems respond to dehydration or hemorrhage to restore blood volume and pressure. Compare how the body responds to osmolar vs. isotonic disturbances .

Explore how aldosterone regulates potassium levels and how parathyroid hormone (PTH) maintains calcium balance. Learn the causes and effects of hyperkalemia, hypokalemia, hypercalcemia, and hypocalcemia , and why they matter for muscle and nerve function.

Understand how the body regulates osmolarity through osmoreceptors, ADH release, and thirst mechanisms . Explore how water gain and loss affect osmolarity and how the body restores balance during dehydration or fluid overload.

Break down how total body water is distributed between the intracellular fluid (ICF) and extracellular fluid (ECF) compartments. Learn about solute concentrations , fluid movement , and the importance of maintaining fluid balance for homeostasis.

Explore how the sympathetic nervous system, RAAS, ADH, and natriuretic peptides regulate GFR in response to systemic blood pressure and volume changes , ensuring whole-body fluid and pressure homeostasis.

Understand how the kidneys regulate their own filtration rate using the myogenic mechanism and tubuloglomerular feedback , maintaining stable GFR despite changes in blood pressure.

Learn how GFR is calculated using Starling forces , how arteriole diameter affects filtration, and why GFR is a key measure of kidney function and fluid balance .

Discover how different parts of the nephron contribute to urine formation and how osmolarity changes throughout. Learn how countercurrent mechanisms create and preserve the medullary concentration gradient .

Review the major functions of the urinary system , including waste excretion, fluid and electrolyte balance, and blood pressure regulation . Understand the differences between plasma, filtrate, and urine , and the processes of filtration, reabsorption, secretion, and excretion .

Explore how hydrostatic and oncotic pressures regulate capillary exchange . Learn how net filtration pressure (NFP) drives fluid in or out of capillaries and how the lymphatic system prevents edema by returning excess fluid to circulation.

Understand how local control mechanisms adjust blood flow to match tissue demand . Explore metabolic and myogenic responses, precapillary sphincters, and the balance between vasodilation and vasoconstriction in maintaining perfusion .

Learn how central and peripheral chemoreceptors regulate breathing in response to CO₂, O₂, and pH levels . Understand how hyperventilation affects breath-holding time and why neural input anticipates respiratory changes during exercise .