Kidney histology Flashcards
What is found in the kidney hilum
Renal pelvis and major vessels
What is found in the renal cortex
Renal corpuscles
Convuluted tubules
What is found in the renal medulla
Medullary pyraminds
Loops of Henle
Collecting duct
Vasa recta
Describe the sequence of branching of the renal artery
Renal artery Main branch renal artery artery Interlobar artery Arcuate artery Interlobular artery Afferent arteriole Glomerulus Efferent arteriole
What supports the bowmans capsule
Mesangial cells and extracellular matrixx
What makes up the renal corpuscle
Bowmans capsule
Glomerulus
Mesangium
What are the 3 elements of the glomerular filtration barrier
Fenestrated capillary endothelium
Basement membrane
Podocyte layer of Bowmans capsule
What is absorbed in the proximal convuluted tubule? In what percentages
70-80% of water
100% of amino aicds and glucose
Some bicarbonates
What is secreted in the proximal convuluted tubule
Hydrogen ions
Describe the histological appearance of the proximal convuluted tubule
Microvilllus brush border
Endocytotic vesicles
Lysosomes
What epithelium is found in descending limb of the loop of henle
Simple squamous epithelium
What is the descending limb of the loop of Henle permeable to?
Urea and water
Less permeable to Nacl
What is ascending limb of loop of Henle permeable and impermeable to
Impermeable to water
Allows some NaCl diffusion
What epithelium is found in the ascending limb of the loop of henle
Simple cuboidal
What is activelly transported out of the ascending limb of henle
Na+ (without water)
2 functions of the distal convuluted tubule
1) Water balance
2) Electrolyte and acid/ base balance
How does distal convuluted tubule help control water balance
Tubules reabsorb water in the presence of adh
How does distal convuluted tubule help control electrolyte and acid base balance
Na+ reabsoption coupled to K+
H+ secretion under control of aldosteronre
Describe the histological appearance of the distal convoluted tubule
Simple cuboidal epithelium
Few microvilli or endocytotic vesicles
Basal or lateral interdigitations reflecting ion transport requirements
What is the mucula densa
Specialised region at vascular pole of nephron- part of juxtaglomerular apparatus
Function of the justaglomerular apparatus
Regulates blood pressure and volume
What cells make up the juxtaglomerular apparatus
Juxtaglomerular cells
Macula densa
Extraglomerular mesangial cells
What is the role of the juxtaglomerular cells
Afferent arteriole senses decreases in the blood pressure and secretes more renin
What does the macula densa detect
Decreased sodium content of distal tubule
What epithelium is found in the collecting duct
Simple cuboidal–> columnar epithelium
What epithelium is found in urinary passageways
Transitional epithelium
What junctions are found in mucosa of urinary pathways
Tight junctions
Is there a lamina propria in urinary passageway? What about muscularis mucosae
Lamina propria but no muscularis mucosae
What kind of muscle is found in urinary passageways
Smooth
What are the layers of the urinary passageways
- Innermost longitudinal (loose spiral)
- Middle circular (tight circle)
- Outermost longitudinal (loose spiral) beginning at lower ureter
Where do the ureters enter the bladder
Posterolateral wall
How is backflow from the bladder prevented
Filling closes the lumen
What forms the internal sphincter at beginning of urethra
Middle circular smooth muscle layer
