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Urinary system
Chapter 18 definitions
Term | Definition |
---|---|
Excretion | Process of eliminating wastes from the body |
Renal cortex | Forms the outer region of the kidney |
Renal medulla | Forms the inner region of the kidney |
Renal pyramids | Cone-shaped sections of the renal medulla that consists of tubules for transporting urine away from the cortex |
Renal papilla | Point of the renal medulla that faces the hilum |
Minor calyx | Cup that collects urine leaving the renal papilla |
Major calyx | Where 2 or 3 minor calyces join together |
Renal pelvis | Receives urine from the major calyces |
Renal artery | Branches off the abdominal aorta and brings blood to the kidney |
Renal vein | Empties blood leaving the kidney into the inferior vena cava |
Nephrons | Filtration units of the kidney; extend between the cortex and the medulla; well supplied with blood |
Afferent arterioles | Arising from smaller arteries, supplies blood to 1 nephron |
Glomerulus | Cluster of capillaries enclosed by Bowman's capsule |
Efferent arteriole | Where blood leaves the glomerulus |
Peritubular capillaries | Network of capillaries around the renal tubules; pick up water and solutes reabsorbed by the renal tubules |
Renal corpuscle | Beginning of the nephron; consists of a glomerulus and Bowman's capsule |
Renal tubule | Series of tube-like structures leading away from the glomerulus |
Collecting duct | Receives drainage from the distal convoluted tubules of several different nephons |
GFR | Glomerular filtration rate; the amount of fluid filtered by both kidneys; about 180 liters each day |
Proteinuria | Abnormal presence of protein in the urine |
Aldosterone | Hormone secreted by the adrenal glands that causes the distal convoluted tubule to retain Na+, which leads to increased retention of water. Blood volume increases and blood pressure rises |
ANP | Atrial natriuretic peptide; hormone secreted by the atria of the heartwhich inhibits secretion of aldosterone and antidiuretic; reduces blood volume and pressure |
ADH | Antidiuretic hormone; secreted by the posterior pituitary gland, causes the distal and collecting tubes to be more permeable to H2O; urine volume falls, blood pressure and volume increase |
PTH | Parathyroid hormone; Secreted by the parathyroid glands; prompts the renal tubules to reabsorb more calcium and excrete more phosphate |
Urinalysis | Examination of the characteristics of urine |
Oliguria | Urine output of less than 400ml/day; insufficient for clearing waste products from the body |
Detrusor muscle | Wall of the bladder consisting of 3 layers of smooth muscle |
Rugae | Folds of mucous transitional epithelium lining the bladder |
Trigone | Triangular shaped, smooth area on the floor of the bladder; commonly attacked by infections |
Internal urethral sphincter | Ring of smooth muscle where the urethra leaves the bladder; contracts involuntarily to retain urine in the bladder |
External urinary sphincter | Where the urethra passes thru the pelvic floor; consists of skeletal muscle under voluntary control |
External urinary meatus | The opening of the urethra leading to the outside of the body |
Angiotensin | Plasma protein produced when renin is released from the kidney |
Angiotensin II | Stimulates the adrenal glands to secrete aldosterone |
Diuresis | Secretion of large amounts of urine |
Hilum | Concave notch on the medial side of the kidney; where blood vessels, the ureters, and nerves enter and leave the kidney |
Renin | Enzyme released by the kidneys in response to a drop in blood pressure that causes the conversion of angiotensinogen into angiotensin I |
Specific gravity | Measurement that indicates the amount of solid matter in a liquid |