PSYCH 3CC3 Lecture Notes - Lecture 4: Menorrhagia, Adrenal Gland, Extracellular Fluid
11 Mar 2018
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Document Summary
Rises to the top of priorities when an individual is deprived of water. Body seeks to maintain the desirable level of water through intake and excretion. Accounts for 1/3 of total water in body. Water outside cells (in blood, csf, body cavities) Induced by perspiration, blood loss, diarrhea, heavy menstrual bleeding. Thirst due to extracellular fluid loss set off by drop in blood pressure. Leads to activation of baroreceptors (blood pressure receptors) in kidneys. Activation of baroreceptors triggers release of renin from kidneys. Renin is an enzyme that produces angiotensin in blood. Angiotensin causes hypothalamus and pituitary to increase production of vasopressin (anti-diuretic hormone) Angiotensin causes adrenal gland to release aldosterone from adrenal cortex. Aldosterone causes kidneys to increase sodium reabsorption. Vasopressin causes kidneys to increase water reabsorption. Accounts for 2/3 of total water in body. Induced by excess salt consumption or severe thirst (dehydration) Excess salt consumption or severe thirst leads to increased extracellular sodium.
