Pharm-Ch. 50 Flashcards
Aldosterone
hormone produced by the adrenal gland that causes the distal tubule to retain sodium, and therefore water, while losing potassium into the urine.
ADH
Antidiuretic Hormone. Hormone produced by the hypothalamus and stored in the posterior pituitary gland; important in maintaining fluid balance; causes the distal tubules and collecting ducts of the kidney to become permeable to water, leading to an antidiuretic effect and fluid retention.
Carbonic Anhydrase
a catalyst that speeds up the chemical reaction combining water and carbon dioxide, which react to form carbonic acid and immediately dissociate to form sodium bicarbonate.
Countercurrent Mechanism
process used by medullary nephrons to concentrate or dilute the urine in response to body stimuli to maintain fluid and electrolyte balance.
Filtration
passage of fluid and small components of the blood through the glomerulus into the nephron tubule.
Glomerulus
the tuft of blood vessel between the afferent and efferent arterioles in the nephron; the fenestrated membrane of the glomerulus allows filtration of fluid from the blood into the nephron tubule.
Nephron
functional unit of the kidney, composed of Bowman’s capsule, the proximal and distal convoluted tubules, and the collecting duct.
Prostate Gland
gland located around the male urethra; responsible for producing an acidic fluid that maintains sperm and lubricates the urinary tract.
Reabsorption
the movement of substances from the renal tubule back into the vascular system.
Renin-Angiotensin-Aldosterone System
compensatory process that leads to increased blood pressure and blood volume to ensure perfusion of the kidneys; important in the continual regulation of blood pressure.
Secretion
the active movement of substances from the blood into the renal tubule for excretion.
