Histo Urinary Notes

Front 1

Renal lobe

Back 1

Pyramid + associated cortical tissue

Front 2

Renal lobule

Back 2

Medullary ray + associated cortical tissue.
Does all of the work

Front 3

Filtration apparatus

Back 3

Fenestrated endothelium (no diaphragms),
basal lamina (collagen IV, fibronectin, laminin, heparan sulfate, charge barrier),
filtration slits btwn pedicles of podocytes (with nephrin-containing diaphragms)

Front 4

How to ID renal corpuscles w/ LM

Back 4

Located in renal cortex
Nuclei of endothelial cells, podocytes, and mesangial cells are all centrally located
Clear urinary space surrounds nuclei
Parietal epithelial cells of Bowman's capsule = simple squamous, become cuboidal at start of proximal tubule

Front 5

Cells of proximal tubule will have

Back 5

Microvilli
Mitochondria
Membrane infoldings

Front 6

How to ID proximal tubules w/ LM

Back 6

Located in renal cortex, medullary ray
Simple cuboidal, nucleated cells w/ brush border
Luminal debris (denatured oligopeptides)
Indistinct cellular outlines d/t numerous infoldings of PM
Basal mitos contribute to pronounced eosinophilia

Front 7

Proximal tubules and Vitamin D

Back 7

Proximal tubules have 1-alpha hydroxylase which is necessary for converting 25-OH-D3 to 1,25(OH)D3.
Conversion occurs in mitos of epithelial cells of proximal tubules

Front 8

How to ID Henle loops w/ LM

Back 8

Located primarily in medulla and also in inner cortex
Simple squamous epithelial cells
Differentiated from capillaries by absence of blood

Front 9

How to ID distal tubules w/ LM

Back 9

Located in renal cortex, medullary rays
Simple cuboidal, nucleated cells (brush border not visible)
Little luminal debris
Indistinct cellular outlines d/t infoldings of PM
Basal mitos contribute to eosinophilia

Front 10

Juxtaglomerular apparatus

Back 10

Junction of thick ascending limb and DCT.
Contains macula densa cells, juxtaglomerular cells (modified SM cells in the wall (tunica media) of the afferent arteriole), extraglomerular mesangeial cells (outside renal corpuscle)

Front 11

Where does gluconeogenesis occur in the kidney?

Back 11

Epithelial cells of the proximal convoluted tubule

Front 12

How to ID collecting tubules w/ LM

Back 12

Located in medulla, and medullary rays
Simple cuboidal, nucleated cells, becoming taller towards papilla
Many light-staining principal and fewer dark-staining intercalated cells
Cellular outlines clear

Front 13

Urothelium

Back 13

Transitional epithelium, surrounded by smooth muscle arranged in 2-3 layers plus connective tissue
Luminal epithelial layer of urothelium consists of umbrella cells

Front 14

Nephrotic Syndrome

Back 14

1. Proteinuria >3.5 g
2. Edema
3. Decreased serum albumin
4. Increased serum cholesterol

A/w problems in podocytes and/or glomerular basement membrane

Front 15

Nephritic Syndrome

Back 15

Inflammatory diseases.
A/w inflammation in mesangium, endothelium and glomerular basement membrane.
Usually characterized by proteinuria with red cells and RBC casts. This is accompanied clinically by variable degrees of salt and water retention, circulatory congestion, hypertension, and a reduced GFR.
“Classic” causes of nephritic syndrome include Post-Infectious Glomerulonephritis (including post-strep GN) and Systemic Lupus Erythematosus

Front 16

3 primary nephrotic syndromes

Back 16

1. minimal change disease
2. focal segmental glomerulosclerosis
3. membranous nephropathy

Front 17

Glomerular diseases

Back 17

Present w/ proteinuria (typically >1g/24hr) and/or hematuria w/ possible red casts

Front 18

Tubulointerstitial disease

Back 18

Likely to present w/ decrease in GFR, recognized by increase in serum creatinine, and a UA that contains minimal amounts of protein and/or blood

Front 19

Minimal change disease

Back 19

Most common cause of nephrotic syndrome in children. Typically presents as sudden onset of severe NS with hypoalbuminemia, hypercholesterolemia, normal BP, and normal GFR

Front 20

Focal segmental glomerulosclerosis

Back 20

Usually idiopathic, HTN and reduction in GFR common.
Most common cause of idiopathic nephrotic syndrome in
African-Americans.

Front 21

Membranous glomerulopathy

Back 21

More likely in older patients.
Presentation: Proteinuria with variable HTN and decreased GFR.
In 2009, the M-type phospholipase A2 receptor (PLA2R) was identified as the major target podocyte antigen involved in adult autoimmune idiopathic membranous nephropathy.