Physiology 3120 Lecture Notes - Macula Densa, Carotid Sinus, Juxtaglomerular Cell

• School: Western University
• Department: Physiology
• Course: Physiology 3120
• Professor: Tom Stavraky

Document Summary

When na is low, ecf decreases and so does bp. Baroreceptors in carotid sinus innervate the juxtaglomerular cells (neural reflex) Fewer aps in baroreceptors; stimulates juxtaglomerular cells to release renin. Regulation of renin release: baroreceptors, carotid sinus b. When bp decreases, juxtaglomerular cells beside afferent arteriole deform less and therefore secrete renin. Cells in macula densa can detect levels of nacl in filtrate. Decrease in na stimulates juxtaglomerular cells nearby to release renin. Regulation of aldosterone release: angiotensin ii, potassium. High levels of potassium in blood directly stimulates adrenal gland to produce & release aldosterone: adrenal corticotropic hormone (acth) Hormone that is released by anterior pituitary gland. Inhibits na reabsorption: peptide hormone (charged) made by cardiac atrial cells, released when cardiac cells distended; activated by stretch receptors (increased bp and ecf volume) Inhibits aldosterone release, which prevents na reabsorption; also, increases gfr by dilating the afferent arteriole (i. e. more filtrate, more salt excreted)