Kidney: Structure Flashcards
Where are the kidneys positioned?
Either side of spine, below lowest rib
How does blood enter and leave the kidneys?
Blood from renal artery, blood drained by renal vein
What is the role of the kidneys?
Remove waste products from the blood and produce urine (passes down ureter to bladder)
What would you see on a longitudinal section of the kidney?
Surrounded by tough capsule, outer region = cortex, inner region = medulla, centre= pelvis, leads to ureter
What do kidneys mainly consist of?
Tiny tubules: nephrons, 1 million in each kidney, closely associated with many blood capillaries
Where does each nephron start?
Cortex
What are the structures of the nephron from beginning to end?
Capillary knot: glomerulus, surrounded by Bowman’s capsule, proximal convoluted tubule, Loop of Henle (descending then ascending limb), distal convoluted tubule, collecting duct
What are the arterioles that supply and remove blood from the glomerular capillary?
Branch of renal artery: afferent arteriole, efferent arteriole
Which parts of the nephron are in the cortex (top part) of kidney?
Glomerulus, Bowman’s capsule, PCT, DCT, half of collecting duct (branch of renal artery surrounding)
How is the composition of the fluid in the nephron altered?
Selective reabsorption, substances reabsorbed back into the tissue fluid and blood capillaries, final product is urine
How does the composition of the fluid in the nephron change?
In PCT all sugars, most salts and some water reabsorbed, 85% fluid reabsorbed here. In descending limb of LoH: water potential decreased by salt addition and H2O removal, ascending limb = water potential increased by salt removal (active transport), collecting duct: water removed so urine has low water potential
What does urine have in comparison to blood and tissue fluid?
Urine has higher concentrates of solutes
