Kidneys Flashcards
(20 cards)
What is the function of the kidney
Filter blood and move nitrogenous metabolic waste to produce urine and osmoregulatuon
What is ultrafiltration
Filtration of small molecules from blood plasma to the lumen of the bowman’s capsule under high pressure
What does the afferent arteriolar branch into
Lots of capillaries inside the cup of the bowman’s capsule
What are the network of capillaries surrounding the bowman’s capsule called
Glomerulus
Why is a high filtration pressure produced
Because of the high hydrostatic blood pressure in the renal artery and the difference in diameter of the afferent and efferent arteriolar
What are capillary pores called
Fenestrations
What is the basement membrane
Extra cellular layer of proteins mainly collagen and glycoproteins which act as a molecular filter
What are podocytes
Epithelial cells that wrap around the glomerular capillaries preventing the loss of proteins
Is most reabsorption passive or active
Most uses membrane pumps but some is passive
How is glucose transported in the pct
Co transport with sodium through a channel protein into the capillary
What is the function of the loop of gentle
Conserve water by concentrating salts in the medulla by active transport
How does the ascending loop of henle work
It pumps out sodium and calcium actively which causes the solute potential of the medulla tissue fluid to decrease
What happens in the descending limb
Water moves out of it by osmosis
Why doesn’t water released by the descending limb affect solute potential
It moves directly into the blood capillaries by vasoconstriction
What happens to the fluid in the descending limb as it goes down
It becomes more concentrated
Where are the filtrate ij the descending limb and the tissue fluid most concentrated
At the tip of the loop of henle
What is negative feedback
Moving away from a set point causes changes that return body to a set point
What is positive feedback
Change away from the set point causes changes causes futger change away from the set point eg blood clotting
What are target cells
Cells that have receptors embedded in the plasma membrane that are complementary in shape to specific hormone molecules
