Histology of the Kidney Flashcards Preview

CVPR: Renal > Histology of the Kidney > Flashcards

Flashcards in Histology of the Kidney Deck (13)
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1
Q

Anatomical features of the kidney

A
  • capsule surrounds outer cortex of kidney
  • under cortex ==> medullary pyramids
    • pyramids = collection of nephrons + collecting ducts
  • collecting ducts ==> empty at tip of pyramid (papilla) into calyx
  • Calices ==> renal pelvis ==> ureter @ hilum
    • hilum = central region
    • hilum also = site of entry of renal artery and vein
2
Q

Vasculature/blood flow (renal artery ==> renal vein)

A
  • renal artery ==> interlobar arteries = between medullary pyramids
  • ==> arcuate arteries ==> interlobular arteries ==> afferent arterioles ==> glomerular capillaries
  • filtration @ glomeruli ==> efferent arterioles
    • @ outer cortex ==> capillary plexus @ tubules and extend as vasa recta into medulla
    • @ medulla ==> enter directly into medullary region
  • capillaries ==> interlobular veins ==> arcuate veins ==> interlobar veins ==> renal vein
3
Q

Nephron: general characteristics

A
  • basic fxn unit of the kidney
  • =renal corpuscules + renal tubules
    • corpuscules @ cortex
    • tubule @ extends into medulla
    • loop of Henle = bend of tubule
4
Q

Renal corpuscle characteristics

A
  • =where blood filtration occurs
  • =glomerulus (capillary network) + Bowman’s capsule (epithelial capsule)
  • glomerulus
    • interior = mesangium (mesangial cells)
    • endothelial lining
  • Basal lamina = filtration barrier
  • Bowman’s capsule
    • outer layer = parietal epithelium
    • layer of podocytes = visceral epithelium of Bowman’s capsule
    • begining of urinary space
5
Q

Filtration barrier characteristics

A
  • = fenestrated endothelium + shared basal lamina + filtration slits between podocytes
  • filtration = driven by hydrostratic pressure of blood
  • fenestrae prevent cellular components from contacting basal lamina, but all other components can pass through
6
Q

Elements of blood that do not readily enter filtrate @ Bowman’s capsule

A
  • large proteins/cellular components
  • mlx > 60-70,000 MW in size (albumin, etc.) <== prevented by basal lamina
  • negative mlx have more difficult passing through
7
Q

Purpose of mesangial cells

A
  • =connective tissue
  • supports glomerular structure
  • secrete matrix that is continous w/basal lamina
  • mesangial cells = phagocytic ==> maintian filtration lamina
8
Q

Main sections of the tubular portion of nephron

A
  1. proximal convoluted and straight tubule
  2. thin descending loop of Henle
  3. thin ascending loop of Henle
  4. ascending thick loop of Henle
  5. distal convoluted tubule
  6. collecting tubule
9
Q

Proximal tubule characteristics

A
  • cuboidal epithelium + microvilli brush border on luminal side
  • cells @ luminal surface connected by tight jxns
  • basolateral side
    • extensive folds
    • Na+/K+ ATPase ++ ==> drives uptake of sodium, glucose, amino acids via facilitated diffusion
10
Q

Loop of Henle general characteristics

A
  • thin descending ==> thin ascending ==> thick ascending
  • thin = simple squamous
    • maintains osmotic salt gradient in medulla
  • thick = cuboidal
    • active sodium transport
11
Q

Distal tubule general characteristics

A
  • cuboidal + microvilli
  • acid-base regulation
  • Na+/K+ ATPase transporters
12
Q

Collecting tubules/ducts

A
  • cuboidal
  • =principal + intercalated cells
    • principal = active transporters
    • intercalated = secrete H+ + reabsorb bicarbonate (acid-base regulation)
  • ADH ==> regulates water permeability/reabsorption by collecting ducts
  • ducts join together and drain ==> papillary ducts ==> minor calices
13
Q

Juxtaglomerular complex characteristics

A
  • =specialization of cells @ vascular pole of renal corpuscle
  • JG cells = modified smooth muscle cells @ wall of afferent arteriole
    • contain renin granules ==> control systemic/local BP w/release