This document discusses the structure and function of the nephron, the functional unit of the kidney. It describes the key parts of the nephron including the glomerulus, Bowman's capsule, and renal tubules. The glomerulus is made up of capillaries, podocytes, and the glomerular basement membrane. It acts as a filter, allowing filtration of blood to form urine but preventing large molecules from passing through. The mesangium supports the glomerular capillaries and maintains the glomerular basement membrane. Kidney diseases like nephrotic syndrome and glomerulonephritis can result from damage to parts of the nephron like the basement membrane or podocytes.

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.