Kidney Histology Flashcards

Filtration of blood (via glomeruli)
-excretion of wate products
-elimination of foreign substances
-control of concentration of most compounds in extracellular fluid

regulation
-amount of water in body
-blood volume
-concentrayion of blood solutes
-pH of extracellular fluid
-blood cell synthesis

synthesis
-vitamin D
-erythropoietin
-renin

selective reabsorption and excretion - tubular system of kidney

*outer layer is cortex
*inner region is medulla
*medulla has pyramidal segments with base at cortex-medullary junction & apex at minor calyx of uteter
*renal papilae w/openings of collecting ducts
*medullary rays

*tubules from medulla extend into cortex from pyramid base
*medullary ray + nephrons that belong to it make up a renal lobe

Medullary ray + nephrons that belong to it

*surrounds each kidney
*dense connective tissue

*where renal artery and nerves enter + renal veins and ureter exit the kidneys

*1-4 million inj each kidney
*renal corpuscle (Bowman's capsule) with glomerulus formation of the filtrate
*proximal convoluted tubule - sodium and nutrients are reabsorbed
*thin + thick loops of Henle - water exits, Na, Cl, K are transported out and urine is concentrated
*distal convoluted tubule - water movement out (if needed)
*nephron leads to collecting tubules and ducts which are not part of nephron itself

*200 micrometers in diameter*vascular pole where the afferent arteriole enters + efferent arteriole departs
*urinary pole - proximal convoluted tubule

Afferent arteriole
to
glomerular tuft
to
efferent arteriole

*fenestrated capillary endothelium
*small cells w/dense dark nuclei

*URINE COLLECTION
*parietal layer - simple squamous epithelium with basal lamina and reticular fibers
*urinary (Bowman's) space
*visceral layer - podocytes; openings between podicles (about 25 micrometers) are called filtration slits
*large cells with euchromatin (light) nuclei

*epithelial cells with foot processes that cover blood vessels
*@ Bowman's capsule - visceral layer

*@ visceral layer of Bowman's capsule
*openings between podicles

*serves as filtration barrier
*100-300nm
*made up of fusion of epithelial and endothelial cells
*composed os collagen type IV
*rich in heparan sulfate
*negative charge + slit size serve as major filter barriers

*@ glomerulus
*form a connective tissue that gives structural support to podocytes and vessels
*may act as macrophages to clean basal membrane

*dense row of nuclei in distal tubule wall that is closest to the vascular pole of the glomerulus