Renal Flashcards
Anatomy of the kidneys
Located between T12 and L3
Three surrounding layers - renal fascia, adipose tissue and renal capsule
Retroperitoneal
R kidney sits lower because of liver
Blood flow through kidneys
Aorta ➡️ L/R renal artery ➡️ segmental artery ➡️ interlobar artery ➡️ arcuate artery ➡️ cortical radiate arteries ➡️ afferent arteriole ➡️ glomerular capillaries ➡️ efferent arteriole ➡️ peritubilar capillaries ➡️ cortical radiate veins ➡️ arcuate vein ➡️ interlobar vein ➡️ L/R renal vein ➡️ IVC
Cells of the juxtomedullary complex
Macula densa cells
- Are on the distal convoluted tubule
- Sense low Na and Cl
- Signal juxtoglomerullar cells
Juxtoglomerullar cells
- found next to afferent arteriole
- Sense low BP
- Release renin
Extraglomerular mesangial cell
- Regulate interaction between macula densa cells and juxtoglomerullar cells
Functions of renin
Increases Na reabsorption
Vasoconstriction
Increases BP
IgA nephropathy pathophysiology
- Formation of abnormal IgA antibodies with lack of glycosylated amino acids. - - These accumulate and form immune complexes with IgG antibodies which get deposited in the glomerular membrane of Bowman’s capsule.
- Causes a type III hypersensitivity reaction (occurs at site of deposition, not formation)
- Activation of inflammatory cytokines and macrophages in area causes damage of glomerular membrane
IgA nephropathy symptoms
- Most common nephropathy in the world
- Occurs mostly in children
- Following an acute mucosal infection (GI/URTI)
- Gross or microscopic haematuria
- Type of nephritic syndrome
- Repeated glomerular insult results in renal failure
IgA nephropathy signs
- Light microscopy: mesangial proliferation
- Electron microscopy: Immune complex deposition in glomerulus
- Immunofluorescense: IgA deposition
IgA nephropathy treatment
- only recommended when proteinuria > 0.5g, abnormal BP or abnormal eGFR
- Lifestyle changes for BP control
- Antihypertensives - ACE inhibitors: also reduce proteinuria, can also use ARBs
- Corticosteroids: consider in patients who have persistent proteinuria despite ACEi/ARB use
Henoch-Schonlein Purpura (HSP) and IgA nephropathy
- Similar findings on light microscopy, electron microscopy and immunofluorescence: IgA immune complex deposition
- In HSP, deposition occurs widespread in body, but in IgA nephropathy deposition occurs only in kidneys