Urinary Flashcards
(51 cards)
Nephron Structure (12)
Afferent and efferent arterioles - glomerulus - proximal convoluted tubule - continuous to thick descending limb - loop of Henle (thin descending limb to thin ascending limb) - thick ascending limb - continuous w/ distal convoluted tubule - collecting tubule - collecting duct
3 Layers of Bowman’s Capsule (and what made up by)
Parietal layer - simple squamos epithelium
Bowman’s space (urinary space)
Visceral Layer - podocytes
Podocytes
Cells that sit between capillary itself and urinary space, so that’s what things have to filter through to get to urinary space
Podocyte Structure (2)
Primary processes which break into secondary processes (pedicels) which interdigitate w/ 2ndary processes of another podocyte to cover blood vessels
Filtration Slits
Spaces between interdigitation of podocyte secondary processes where filtration actually takes place
Filtration Barrier
Thick basal lamina
Capillary Type in Glomeruli
Type II non-diaphragmed
Albumin
69k MW, so exact size of filtration barrier so checked for in urine to see kidney function
Mesangeal Cells
Supportive cells in glomerulus which provide structural support to hold capillaries/podocytes in tuft/ball
6 Features of Proximal Convoluted Tubule/Thick Descending Tubule
Simple cuboidal epithelium Intensely eosinophilic - lots of mts Prominent brush border - narrow lumen Numerous lateral folds and basal striations Euchromatic Nucleus
3 Functions of Proximal Convoluted Tubule/Thick Descending Tubule (total 9)
Absorbs Na, Cl, and water follows via aquaporins
Absorbs glucose, AAs, and most prots
Excretes organic solutes, toxins, drugs
Lateral Folds of PCT
Lateral borders of cells interdigitate with each other
3 Features of Loop of Henle (& location)
In medulla
Simple squamos epithelium
Nuclei bulge into lumen
Highly permeable to water, ions, urea
5 Features of Distal Convoluted Tubule
Simple cuboidal epithelium Weakly eosinophilic Low brush border-wider lumen Impermeable to water/urea Low salt/higher urea conc in lumen
Aldosterone
Made in zona glomerulosa in cortex of adrenal gland, regulates salt pumping in DCT
Function of DCT
Pumps out Na, Cl follows
Macula Densa
Region of DCT that runs past vascular pole of glomerulus and senses salt levels to change/regulate
3 Regions of Collecting Tubule/Duct
Cortical
Medullary
Papillary
4 Features of Collecting Tubules/Ducts
Simple cuboidal epithelium
Very pale cytoplasm
Prominent lateral cell boundaries
Luminal (apical) surface may be scalloped
Antidiuretic Hormone (ADH)
Comes from post. pit. and acts on collecting ducts to stimulate aquaporin channels to concentrate urine
3 Components of Juxtaglomerular Apparatus (+ source and function)
Macula densa (DCT) - measures Na concentration Juxtaglomerular cells (afferent arteriole) - renin production Extraglomerular Mesangial Cells (lacis cells) - support
Renin
Released by juxtaglomerular cells in kidney, acts on angiotensinogen from liver and does a lot of things to increase BP
Arterial Blood Supply Progression to Kidneys (12)
Renal artery to segmental arteries to lobar arteries to interlobar a.s to arcuate a.s to interlobular a.s to afferent arterioles to glomerular capillaries to efferent arterioles to pertiubular capillary network or vasa recta to stellate veins then mirrors arterial supply
Arcuate Arteries
Run between cortex and medulla of kidneys, at corticomedullary junction
