Ivy Tech
excretion - ANS-the removal of metabolic wastes from the body
waste - ANS-any substance that is useless to the body or present in excess of the
body's needs
metabolic waste - ANS-substances produced by the metabolic activities of living
organisms. These substances cannot be used by the organism and are therefore
excreted. These excretes include carbon dioxide, nitrogen compounds, sulfates,
phosphates and water.
function of the kidneys - ANS-1. removal of excess salts and metabolic wastes with
urine
2. maintaining normal water and electrolyte concentration
3. regulating pH of body fluids
4. secrete the hormone erythropoietin which controls red blood cell production
5. secrete the hormone renin to control blood pressure
6. returns useful chemicals to blood
7. activate vitamin D
organs of the urinary system - ANS-kidneys, ureters, urinary bladder, urethra
the urinary system excretes _____ - ANS-metabolic wastes, toxins, drugs, hormones,
salts, H+, and water
urea - ANS-1. proteins --> amino acids --> forms ammonia
2. ammonia is a byproduct of protein metabolism: toxic to body tissues and is converted
into _________ by liver
uric acid - ANS-product of nucleic acid catabolism (DNA and RNA)
creatinine - ANS-product of creatinine phosphate catabolism (from skeletal muscle
cells)
What body systems carry out excretion? - ANS-1. integumentary - sweat production
(contains water, salt, urea)
, 2. respiratory - expired air contains CO2 and water vapor
3. digestive - feces contains water, salts, CO2, lipids, bile pigments, cholesterol, other
metabolic waste, and food residue
4. urinary - many metabolic wastes, toxins, drugs, hormones, salts, H+, and water
afferent arteriole - ANS-blood vessel that supplies the glomerulus and is important in
regulation of glomerular blood pressure
efferent arteriole - ANS-form from a convergence of the capillaries of the glomerulus.
They play an important role in maintaining the glomerular filtration rate despite
fluctuations in blood pressure. Contain blood with high osmotic pressure
efferent arteriole - ANS-blood in what vessel has the highest osmotic pressure in the
body?
renal portal system - ANS-two capillary beds in a row: afferent arteriole -> glomerulus
(1st capillary bed) -> efferent arteriole -> peritubular capillaries (2nd capillary bed)
afferent arteriolar vasodilationon; efferent arteriolar vasoconstriction - ANS-What would
cause an increase in glomerular filtration rate (GFR)?
afferent arteriolar vasoconstricton; efferent arteriolar vasodilation - ANS-What would
cause an decrease in glomerular filtration rate (GFR)?
peritubular capillaries - ANS-branch off of the efferent arterioles supplying the tissue
near the glomerulus, the proximal and distal convoluted tubules. Contain blood with high
osmotic pressure.
vasa recta - ANS-capillary bed branched from the efferent arteriole of juxtamedullary
nephron. Aids in the production of concentrated urine.
what is the functional and structural unit of the kidney? - ANS-nephron
nephron - ANS-urine producing apparatus of the kidney; (renal corpsule, renal tubule)
renal corpuscle - ANS-it is the blood filtering component of the nephron that consists of
the glomerulus and Bowman's capsule