BIOM 3200 Lecture Notes - Lecture 1: Vasopressin, Mast Cell, Vasoconstriction
9 Dec 2017
School
Department
Course
Professor
Document Summary
The adrenal cortex and adrenal medulla are structurally and functionally different. Adrenal medulla secretes catecholamine hormones: mainly epinephrine, with lesser amounts of norepinephrine, these complement the sympathetic nervous system in the fight or flight reaction. Adrenal glands: paired organs that cap the superior borders of the kidneys. The cortex of the adrenal glands secretes corticosteroids/corticoids. Concentration of potassium is usually 4. 5 mmol/l: a doubling of this can be lethal, so potassium is regulated within narrow limits. Potassium ion is filtered at the glomerulus and is all reabsorbed. The amount lost in the urine depends on secretion = aldosterone regulates secretion = aldosterone controls the concentration of plasma potassium. The reabsorption of sodium normally has little effect on the concentration of sodium in extracellular fluid b/c there is an osmotic reabsorption of water: aldosterone regulates only about 2% of sodium reabsorption but this is critical.
