Renal Histology Flashcards
Mar 7th 2013
Urinary System F
- Filters blood & produces urine
- eliminate metabolic waste & toxins from blood
- control H2O and ion balance by reabsorbing Na+ and secreting K+
- maintain acid-base pH of blood
- Regulate BP (produce & release renin)
Kidney Anatomy
Kidney Anatomy
From medullary pyramids’ base,
// arrays of tubules= medullary rays penetrate cortex
90-95% of blood pass through kidney in cortex
5-10% in medulla
Medulla has straight tubules & collecting ducts
Apex of pyramids= papillae which project into urinary parthway (minor calyces)
Nephron
individual f unit of kidney
filter blood & produces urine
Renal corpuscle found in cortex
& renal tubule
Nephron Anatomy
- Renal Corpuscle
- glomerular capillaries (glomerulus)
- Bowman’s capsule: contains filtrate, which is first step in urine forming
- Associated tubules
- continue w/ Bowman’s capsule, has many division w/ own type of cells
- tubule supposed to transform the filtrate into final urine
Renal Corpuscle
Blood enters through afferent arteriole, circulteas through tuft of capillaries & exits through efferent arteriole
The infiltrate enter urinary space & then proximal convoluted tubule
Glomerulus
Fenestrated endothelium
Covered by podocytes (visceral layer of Bowman’s capsule)
Common Basement Membrane of Podocytes
Podocyte
Visceral layer of Bowman’s capsule
Nuclei bulge out into urinary space
Common basal lamina b/t endothelium & podocytes
Cellular extensions further divide into pedicels.
Pedicels from 2 pdodocytes form filtration slits, which are spanned by thin mem
Have a phagocytic function!
Filtration barrier of glomerulus
Prevents passage of RBCs , leukocytes & platelets
Restricts proteins
Permits water, ions & other small molecs
Glomerulonephritis & diabetes- glomerular filter is altered & becomes more permeable to proteins (proteinuria)!
Cells w/in Corpuscle
Endothelium
Podocytes
Mesangial Cells
Mesangial cells
replace normal CT cells
Intraglomerular mesangial cells interspersed among capillary loops
Extraglomerular mesangial cells (lacis cells) in vascular pole
Contractile & phagocytic
Have R for Ang II & ANP (atrial natriuretic peptide in heart)
Cells of Corpuscle
Mesangial Cell Histo
Negative charges in BM
Tubules of Nephron- PCT
Infiltarte exits Bowman’s @ urinary pole & enter renal tubule
- Proximal convoluted tubule- PCT, longest tubule in cortex
- Simple cuboidal, acidophilic, prominant long microvilli (brush border), basal striations
- reabsorb majority of ions- Na+, HCO3-, glucose, majority of H2O
- basal mem invaginations & associated mitochondria indicate= ion transporting f