Basics of Anatomy and Histology of Kidney of Human Body

1. Presented By :-
Shubham Gupta
1st MBBS
Dept. of Anatomy

2.  Excretory System consists of :
1. A pair of Kidney
2. A pair of Ureter
3. Urinary Bladder
4. Urethra
 Functions :
I. Production
II. Transport
III. Storage
IV. Excretion

3.  Nephron :- Structural and Functional Unit of
Kidney.
 Parts of nephron :-
1. Malphigian Body or Corpuscles or Renal
Corpuscles :-
a. Glomerulus
b. Bowman’s Capsule
2. Renal Tubules-
a. Proximal Convoluted Tubule
b. Loop Of Henle : Ascending limb
: Descending limb
c. Distal Convoluted Tubule
d. Collecting Duct

6.  Network or Tuft of anastomosing capillaries that
perform the 1st step of filtering the blood.
 Present in Cortex part of Kidney.
 Surrounded by double layered Bowman's capsule :-
i. Inner or Visceral Layer :-
-Consists of :- Podocytes
- Pedicles
- Filtration slits
ii. Outer or Parietal Layer :-
-Lining Epithelium :- Simple Squamous
Epithelium.
 According to Gray's - Glomerulus is distribution of
blood vessels in the cortex of kidney.

9.  Formed by :-
1. Capillary endothelium
2. Podocyte cells- forming visceral layer of
glomerular capsule.
3. Glomerular basement membrane-
represents the fused basal lamina of above
both lamina.

11.  Formed by :-
1. Capillary endothelium
2. Podocyte cells- forming visceral layer of
glomerular capsule.
3. Glomerular basement membrane-
represents the fused basal lamina of above
both lamina.

12. 1. Endothelial cells : Show numerous fenestrae
or pores through which filtrate can easily pass.

13. 2. Podocytes (foot like processes) :-
- Primary processes :
# Show star shaped appearance
# Wrapped around glomerular capillaries.

14. - Secondary processes(Pedicels or end feet) :
# Each primary process terminates in numerous
Pedicels that rest on basal lamina.

15. - Filtration slits or Slit pores :
# Gaps b/w attachments of individual
pedicels through which filtration takes place.

16.  Formed by fusion of endothelium and podocytes.
 Thickness- about 300 nm.
 Forms both physical as well as electrical barrier
to passage of large molecules [i.e.-
proteins(albumin)].
 Made up of 3 layers :-
a. Lamina densa : Act as a physical barrier
since it contains a network of collagen
fibrils.
b. Lamina rara interna : separates
endothelial cytoplasm from mesangium.
c. Lamina externa.

18.  Forms mesentry like fold over the capillary
loop.
 Contains :-
a. Mesangial matrix
b. Mesangial cells (Lacis cells) :-
- Contains filaments similar to myosin.
- Bear Angiotensin II receptors.
- Stimulation of these receptor by
angiotensin causes fibrils to contract.

20.  Functions :-
a. Supporting glomerular capillaries.
b. Phagocytosis
c. Maintainence of glomerular basement
membrane.

21.  Nephrotic Syndrome :-
 Proteinuria
 Hypoalbuminemia
 Lipidiuria
 Hyperlipidemia
Cause :- Loss of high negative charges in
basement membrane and in podocyte
processes.
 Glomerulonephritis :-
- Due to impaired function of Mesangium,
it lead to Inflammation of Glomerulus.

22.  Importance of Histopathology-
 Kidney biopsy.
 To detect renal pathology.
 During kidney transplantation.