Decrease Hormone regulation July 2018 BIOS256 Midterm Study Guide TYPE OF

Decrease hormone regulation july 2018 bios256 midterm

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Decrease. Hormone regulation July 2018
BIOS256 Midterm Study Guide TYPE OF REGULATION MAJOR STIMULUS MECHANISM AND SITE OF ACTION EFFECT ON GFR Angiotensin II Decreased blood volume or blood pressure stimulates production of angiotensin II. Constriction of afferent and efferent arterioles. Decrease. Atrial natriuretic peptide (ANP) Stretching of atria of heart stimulates secretion of ANP. Relaxation of mesangial cells in glomerulus increases capillary surface area available for filtration. Increase. (Ch. 26) Tubular reabsorption and secretion (Ch. 26) Table 26.4 HORMONE MAJOR STIMULI THAT TRIGGER RELEASE MECHANISM AND SITE OF ACTION EFFECTS Angiotensin II Low blood volume or low blood pressure stimulates renin-induced production of angiotensin II. Stimulates activity of Na + H + antiporters in proximal tubule cells. Increases reabsorption of Na + , other solutes, and water, which increases blood volume and blood pressure. Aldosterone Increased angiotensin II level and increased level of plasma K + promote release of aldosterone by adrenal cortex. Enhances activity of sodium– potassium pumps in basolateral membrane and Na + channels in apical membrane of principal cells in collecting duct. Increases secretion of K + and reabsorption of Na + , Cl ; increases reabsorption of water, which increases blood volume and blood pressure. Antidiuretic hormone (ADH) Increased osmolarity of extracellular fluid or decreased blood volume promotes release of ADH from posterior pituitary gland. Stimulates insertion of water channel proteins (aquaporin- 2) into apical membranes of principal cells. Increases facultative reabsorption of water, which decreases osmolarity of body fluids. Atrial natriuretic peptide (ANP) Stretching of atria of heart stimulates ANP secretion. Suppresses reabsorption of Na + and water in proximal tubule and collecting duct; inhibits secretion of aldosterone and ADH. Increases excretion of Na + in urine (natriuresis); increases urine output (diuresis) and thus decreases blood volume and blood pressure. Parathyroid hormone (PTH) Decreased level of plasma Ca 2+ promotes release of PTH from parathyroid glands. Stimulates opening of Ca 2+ channels in apical membranes of early distal tubule cells. Increases reabsorption of Ca 2+ . (Ch. 26) Formation of concentrated urine (Ch. 26) Evaluation of kidney function Short Answer Questions

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