Urinary/Excretory System Flashcards

Question

calcitrol

Answer 1

helps intestine absorb calcium from food

Answer 2

- primary organs of urine production | - on either side of spine below diaphragm & anterior to deep back muscle

Answer 3

- part of the kidney | - renal artery enters & renal vein leaves

Answer 4

- small muscular tubes that transport urine from kidney to bladder - peristalsis moves urine

Answer 5

- muscular organ that expands as urine enters | - holds up to 600ml of urine

Answer 6

- extends from bladder to external opening - 4cm in females, 20cm in males - shorter length in females makes them more prone to UTI - in males, urethra is surrounded by prostate gland & also carries sperm

Answer 7

As males age, the prostate gland can enlarge and restrict urine flow

Answer 8

- renal cortex: outer layer - renal medulla: inner layer, consists of cone-shaped renal pyramids - renal pelvis: central cavity leading to ureter

Answer 9

microscopic units of kidneys that produce urine... one million per kidney

Answer 10

renal artery -> kidneys -> afferent arteriole -> glomerulus -> efferent arteriole -> peritubular capillary -> venule -> renal vein

Answer 11

capillary knot inside nephron

Answer 12

nephron -> collecting ducts -> renal pelvis -> ureter

Answer 13

- 95% water | - 5% solutes

Answer 14

- ions: H, K, Na, Ca, Cl, Mg - ammonia, sulphates, phosphates - urea - creantinine - uric acid (organic compound from purine breakdown) - others: carbs, enzymes, fatty acids, hormones, pigments & mucins

Answer 15

- old decomposed RBC -> bilirubin -> urobilin = yellow - urinate less = less yellow (diluted urobilin) - if urine stored for a while (ie. overnight) = darker yellow

Answer 16

- diabetics have a sugary smell to their urine | - asparagus can also cause a strong odor

Answer 17

- waste-filled blood enters kidneys - glomular or pressure filtration occurs - tubular or selective reabsorption - loop of henl - tubular secretion

Answer 18

- afferent arterioles enter Bowman's capsule & form a ball of capillaries called glomerulus - efferent arteriole is smaller diameter than the arteriole so blood pressure builds up in glomerulus - blood pressure forces substances from blood into Bowman's capsule

Answer 19

- material forced out of blood = filtrate - has h2o, a.a.'s, glucose, salts, & urea - larger particles (blood cells, proteins, & fats) can't leave capillaries, so they stay in blood & leave via efferent arteriole - efferent arteriole branches into peritubular capillaries which form a mesh around nephron - filtrate moves into proximal convoluted tubule

Answer 20

- in proximal convoluted tubule where some filtrate returns to bloodstream - lined with villi to enhance absorption - active transport moves glucose, a.a's, and Na back into blood - Cl follows passively because it's attracted to Na - with salt leaving (NaCl), h2o follows by osmosis - if amount of substance exceeds number of carrier proteins, not all can be reabsorbed so it ends up in urine

Answer 21

its main job is to regulate water concentration

Answer 22

- 2nd place where substances leave blood & enter nephron - distal convoluted tubule not permeable to H20, so H20 enters capillaries, not nephron - excess H & K ions, drugs, uric acid, products from the breakdown of hemoglobin, histamines, etc. move by active transport from blood to nephron - distal tubules drain into collective duct where more H20 diffuses back into surrounding tissue makes urine more concentrated than blood - fine-tuning of H20 concentration occurs in distal convoluted tubule & collecting tubule

Answer 23

- number of particles per volume of fluid | - maintaining osmolarity in tissues involves h20 regulation

Answer 24

- direct control using ADH | - indirectly through aldosterone

Answer 25

- control of h20 excreted relies on ADH (aka vasopressin) - diuresis means "water-loss", so ADH mean "anti-water-loss hormone" - ADH is made in hypothalamus & stored in posterior pituitary gland - makes you thirsty -> you'll drink more

Answer 26

h20 level drops -> osmolarity increases -> osmoreceptors in hypothalamus direct ADH to be released from pituitary -> ADH binds to receptors of cell on collecting tubule in nephron -> triggers chain of events that lead to insertion of aquaporin channels in collecting duct & distal tubule -> membrane becomes more permeable to water -> water flows out of tube into capillaries to be reclaimed by body -> H20 builds up in body -> osmoregularity back to normal -> shuts down hypothalamus... until the cycle begins again

Answer 27

- ADH secretion is inhibited - aquaporin channels removed by endocytosis - h20 can't leave nephron -> large volume of urine

Answer 28

- inhibit ADH | - urine volume remains large & dehydration can result

Answer 29

- low Na concentration in blood sensed by kidney - through chain of complex chemical signals, kidney sends message to adrenal cortex which releases aldosterone - aldosterone causes nephrons to reabsorb more Na and water back into blood and to excrete more K in urine - when blood Na concentration returns to normal, aldosterone release is stopped

Answer 30

- pH maintained by controlling H levels - only urinary system can eliminate excess H a) HCO3 from nephron moves to capillaries -> resupplies the blood with buffers b) H removed from blood & excreted

Answer 31

- descending limb permeable to H20, so it diffuses into surrounding fluids - filtrate becomes more concentrated as it moves down DL - ascending limb impermeable to H20, but pumps out Na and Cl by active transport - due to that ^, as filtrate moves along AL, it comes less concentrated - at top of AL, there's less filtrate, but it's almost as concentrated as it was at the start of DL - in tissue surrounding loop of Henle, salt gradient is established, increasing concentration from top to bottom of loop & establishing countercurrent multiplying effect - fluid at top of collecting duct has salt concentration about equal to beginning of the loop of Henle - as fluid descends collecting duct, it's exposed to the surrounding salt gradient established by loop of Henle - without ADH, collecting duct is impermeable to H20. 2 outcomes are possible: a) if H20 is needed, ADH simulates opening of aquaporins, allowing H20 to move out of duct and into surrounding tissues b) if h20 not needed by body, no ADH & duct allows h20 to drain out of body