Regulatory function of kidneys

Anat & Physiology 12

ADH (ANTIDIURETIC HORMONE)

Hormone that regulate volume of water in blood released by the pituitary gland at hypothalamus. Promotes reabsorption of water from collecting duct and distal convoluted tubule. Makes blood volume increase and urine decrease.

Hypothalamus

detect low water content in blood and ADH released into blood, also detects when it gets more diluted and ADH stops. Negative feedback loop.

Diuretics drug

Prescribes for high blood pressure. Inhibits ADH secretion. Lower blood volume, blood pressyre decreases, urine more.

Alcohol

inhibits ADH secretion. Alcohol increases urination = dehydration = hangover. Does not help with thirst.

Aldosterone

Made from adrenal glands on top fo the kidneys. Hormone released by the adrenal cortex. Acts on kidney to retain Na+ and excrete K+. Concentration of sodium in blood regulates this.

Hypotension

When [NA+] in blood too low, too little H2O is absorbed

Hypertension

When [NA+] in blood high

Nephrons

Vary the amount of H+ and NH3+ excrete and HCO3- and Na+ they absorb to keep pH balanced.

Electrolyte balance

Reabsorption and excretion of ions (K+ and Mg2+) mains proper __ in the blood