Renal

Question 1

Anatomy of the kidneys

Answer 1

Located between T12 and L3
Three surrounding layers - renal fascia, adipose tissue and renal capsule
Retroperitoneal
R kidney sits lower because of liver

Question 2

Blood flow through kidneys

Answer 2

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

Question 3

Cells of the juxtomedullary complex

Answer 3

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

Question 4

Functions of renin

Answer 4

Increases Na reabsorption
Vasoconstriction
Increases BP

Question 5

IgA nephropathy pathophysiology

Answer 5

• 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

Question 6

IgA nephropathy symptoms

Answer 6

• 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

Question 7

IgA nephropathy signs

Answer 7

• Light microscopy: mesangial proliferation
• Electron microscopy: Immune complex deposition in glomerulus
• Immunofluorescense: IgA deposition

Question 8

IgA nephropathy treatment

Answer 8

• 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

Question 9

Henoch-Schonlein Purpura (HSP) and IgA nephropathy

Answer 9

• 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