exam 4 Flashcards
what are the 7 functions of the kidneys?
- filter waste from blood
- regulate blood volume, pressure, osmolarity
- regulate electrolytes, acid/base balance of body fluids
- secrete erythropoietin
- regulate calcium homeostasis
- clear hormones/drugs from blood
- detoxify free radicals
what makes up the nitrogenous waste portion of urine?
urea, uric acid & creatinine
what is nitrogenous waste?
a toxic type of metabolic waste
what is the renal capsule?
capsule made of collagen fibers that encloses the kidney
what is the renal parenchyma ?
glandular tissue that forms urine
what are the two zones of the renal parenchyma?
cortex and medulla
what is the renal sinus?
cavity within kidney that contains blood vessels, nerves, urine collecting structures
what is the ureter?
collects urine from the renal parenchyma and sends it to bladder
what is the nephron?
functional unit of the kidney
what is the function of the renal corpuscle?
filters blood and contains the glomerulus and the glomerular capsule
what is the function of the glomerulus?
delivers blood to be filtered, filtrate moves through to the renal tubule
what is the function of the renal tubule?
forms urine from filtrate
what is the first stage of urine formation?
glomerular filtration
what is the GFR?
glomerular filtration rate; amount of filtrate formed per minute
what happens if GFR is too high?
fluid flows too quickly through renal tubule, reabsorption of ions and water is inhi
how does blood pressure affect filtration?
a higher BP means more filtration
what is renal autoregulation?
nephrons adjust their own blood flow with no external influence
what is the myogenic mechanism?
smooth muscle of afferent arterioles adjust the diameter of the arterioles based on BP
what happens if the BP is too high ?
arterioles constrict to keep too much blood from entering glomerulus
what happens if the BP is too low?
arterioles dilate to allow enough blood to enter glomerulus
what is reabsorption?
removal of useful molecules, ions from filtrate back into blood
what is secretion?
removal of additional molecules, ions from capillaries into tubule
what is the paracellular route?
substances pass through leaky junctions between epithelial cells
what is the transcellular route?
substances pass through PCT epithelial cells
what are the purposes of tubular secretion?
acid-base balance, waste removal, drug removal
what is the main purpose of the nephron loop?
create osmotic gradient to enable water conservation
what happens in the descending limb of the nephron?
water is pulled out via osmosis
what happens in the ascending limb of the nephron?
salt is pumped out of the loop
tubular reabsorption in the DCT is controlled by what hormones?
parathyroid hormone and aldosterone
what mechanism controls blood pressure and GFR?
renin-angiotensin-aldosterone mechanism
increased production of organic acids by the body can result in…
metabolic acidosis
increased ingestion of acidic drugs can result in…
metabolic acidosis
what is a chemical buffer?
weaker than physiological buffers
what is a base?
compounds that bind H+ ions in solution
the reabsorption of sodium is done in part by cotransporters for sodium and ________ that do not rely on ATP
glucose
what should not be found in the filtrate of a healthy kidney?
proteins
what hormone causes sodium reabsorption from the DCT?
aldosterone
during the early luteal phase, the corpus luteum produces large amounts of estradiol and ___________
progesterone
during the premenstrual phase, a lack of ________ causes the endometrium to degenerate
progesterone
during what phase of the female sexual cycle does the corpus luteum produce high levels of progesterone and estrogen
luteal phase
what happens (in terms of the GFR) when BP drops?
kidneys release renin
renin converts angiotensogen into angiotensin I
angiotensin I converts to angiotensin II
how does angiotensin II raise BP?
causes vasoconstriction, stimulates the adrenal cortex to secrete aldosterone and stimulates posterior pituitary to release antidiuretic hormone
