Kidneys Flashcards
Uriniferous tubule
Nephron + collecting tubule
Renal Corpuscle
Golmerulus + Bowman’s capsule
What is meant by the lobe of the kidney?
Consists of medullary pyramid + associated cortex and half renal columns on either side
If you looked at a medullary ray, what would be the dominant feature?
It contains collecting tubules
What does the cortical labyrinth consists of?
Renal corpuscles and convoluted tubules - not the medullary ray
Follow the course of blood through the kidney
renal artery –> segmental arteries –> interlobar arteries –> arcuate arteries –> interlobular arteries –> afferent arterioles –> glomerular capillaries –> efferent artieroles –> cortical capillary plexus –> drains into interlobular veins or vasa recta.
Both interlobular arteries and vasa recta connect to the arcuate veins – interlobar veins –> real veins
Where does the capillary plexus in the cortical labyrinth come from?
Efferent Arterioles
What is unusual about the embryonic development of the nephron and the collecting ducts?
Come from different embryonic origins and must connect during embryogenisis
Which tubules in the cortex are located in the center of a lobule of the kidney?
Collecting ducts (all uriniferous tubules drain into collect duct)
Where are the renal corpuscles located in the cortex?
85% of renal corpuscles are in the upper cortex
15% are juxtamedullary
What is different between the uriniferous tubules and juxtamedullary renal corpuscles?
?
What is the barrier between the blood and the urinary space in the renal corpuscle?
Fenestrated endothelium, basement membrane, and podocytes with slits between pedicles
What is the structure of the visceral and parietal layer of bowman’s capsule?
Visceral - podocytes
Parietal - simple squamous
What is the function of mesangial cells?
Clean deposited proteins of the basement membrane
- have myosin/actin - thought to help with blood flow
What is unusal about the BM of glomerulus?
thick and neg charged (GAG) repels proteins in blood
What is the progression of filtrate through the uriniferous tubules?
proximal convoluted tubule, loop of henle (thick/thin desc. thin/thick asc limbs), distal convoluted tubule, collecting tubule, collecting duct
What is the structure of the wall of the distal convoluted tubules?
simple cuboidal, no brush border
on an H&E stain, how do you distinguish between PCT, DCT?
PCT - pink, mitochondria, brush border, taller
DCT - closer nuclei
A renal lobule is defined by?
All of the nephrons that drain into a single collecting duct
What is the structure of the thin limbs of henle?
simple squamous
Why are the thin desc and asc limb adjacent to one another?
Allows countercurrent exchange of sodium to preent dilution of the sodium concentration in the renal medulla
What is the function of the thick limb of Henle?
Impermeable to water, has sodium pumps to produce high conc in interstitium
What is the structure of the collecting duct?
narrow to wide, simple cuboidal to columnar, and prominent later infoldings
- principal cells (aquaporins)
- intercalated cells (a and b - involved with H+/HCO2 secretion)
What hormone has has the most powerful on collecting ducts?
ADH - allows water to be reabsorbed into the medulla of kidney and picked up by vasa recta
