Urinary 2 Flashcards
(52 cards)
measures the volume of plasma cleared of a. substance in a given time
renal clearance
clearance equation
RC = (urine concentration x urine flow rate) / plasma concentration
closely approximates GFR and is useful for assessing kidney function
inulin clearance
- involves active or passive transport of substances like H+ ions, penicillin, and K+ ions into the filtrate
- plays a role in controlling the body’s pH balance
tubular secretion
- vasa recta capillaries exchange water for salt as they travel down into the medulla
- system ensures ECF retains high salt levels for water movement out of the nephron
countercurrent exchange mechanism
- maintains high medullary concentration to aid water reabsorption from the nephron
- saltier medulla pulls water out of the descending limb, while salts are pumped out in the descending limb
countercurrent multiplier
countercurrent mechanisms
- countercurrent multiplier
- countercurrent exchange mechanism
what hormone promotes active tubular secretion of potassium and reabsorption of sodium ions in the distal convoluted tubule and collecting ducts
aldosterone
what area of the nephron is responsible for the reabsorption of the most water from the filtrate as well as most nutrients
proximal convoluted tubule
true or false:
Under normal conditions, the proximal convoluted tubule (PCT) reabsorbs nearly all of the glucose, lactate, and amino acids in the filtrate and 65% of the Na+ and water.
true
the kidney are stimulated to produce renin by
a decrease in the blood pressure
contains fluid that becomes more concentrated as it moves down into the medulla
descending limb
effect of ADH on cells of the CD
causes aquaporins to be inserted into apical membranes
true or false:
Filtrate becomes less concentrated as it flows down the medullary collecting ducts, toward the renal pelvis.
false
why does alcohol act as a diuretic
inhibits the release of ADH
- 125ml of filtrate is formed each minute by pushing plasma across the fenestrae of glomerular capillaries into the proximal convoluted tubule.
- Most objects are too large to pass through the small (7nm) barrier
- Plasma proteins and RBCs (>7nm) remain in the capillary, while small hormones and minerals (<7nm) pass through.
filtration membrane
consists of the glomerulus and bowman’s capsule
renal corpuscle / filtration membrane
forces at the filtration membrane
- glomerular blood pressure (GP)
- colloid osmotic pressure (COP)
- capsular hydrostatic pressure (CP)
net filtration pressure (NFP) =
Glomerular Pressure - (Colloid Osmotic Pressure + Capsular Hydrostatic Pressure)
NFP = GP - (COP + CP), with GP pushing water and solutes out, while COP and CP push in the opposite direction.
filtration will still occur as long as
glomerular blood pressure is high enough
how much water is reabsorbed in the nephron and how much is lost as urine
Approximately 123.75ml of water is reabsorbed in the nephron, leaving only 1.25ml/min lost as urine.
plays a significant role in the collecting duct, concentrating urine up to 4 times.
ADH
causes Na+ reabsorption and K+ secretion, leading to water reabsorption in the DCT
aldosterone
