Urinary 2 Flashcards
(17 cards)
What is the glomerular filtration (GFR) rate for women? Men?
Women: 105ml/min - 150L/day
Men: 125ml/min - 180L/day
How much of the filtrate is returned to circulation?
> 98%
How much urine is produced a day?
1-2 L
What influences GFR?
hydrostatic pressure and colloid osmotic pressure
Definition:
pressure produced by fluid against a surface
Hydrostatic pressure
Definition:
Pressure created by the movement of water across a membrane to the high [solute]
Osmotic pressure
Which pressure moves fluid across the capillary wall into the lumen of the bowman’s capsule
Hydrostatic pressure
Definition:
GBHP-CHP-BCOP
net filtration pressure (NFP)
T/F: osmotic pressure is greater than hydrostatic pressure
False! hydrostatic pressure is greater
What is the average NFP?
~10mmHg
Filtration
What happens when BP goes up?
Smooth muscle in afferent arterioles contract while efferent arterioles dilate to limit any increase in blood flow and filtration rate
Steady flow of blood and diltration rate holds true as long as mean arteriol pressure is what?
> 60mmHg
How is the kidney innervated by sympathetic neurons?
Via the celiac plexus and splanchnic nerves
What does reduced sympathetic stimulation of teh kidneys cause?
vasodilation and inc blood flow through the kidneys
What does increased sympathetic stimulation of the kidneys cause?
vasoconstrictiopn resulting in diminished GFR which produces less filtrate
Where is majority (90%) of the water recovered?
PCT, loop of henle, DCT (only 10% reaches the collecting ducts
Where are majority of Na, K, glucose, amino acids and other organic substances like vitamins recovered?
PCT
