Excretory system histology

1. Mohit Rulaniya
Excretory system

2. Excretory system –
The excretory system is a passive biological system that
removes excess, unnecessary materials from the body
fluids of an organism, so as to help maintain internal
chemical homeostasis and prevent damage to the body.
Its consist of –
 Kidneys
 Liver
 Bile
 Large intestine
 Skin
 Eccrine

3. kidney
- The kidneys are two bean-shaped organs.
- Bean shaped, reddish brown.
- Located retroperitoneal between T12 – L3
vertebral level.
- Size approxly 10 x 6.5 x 3 cm.
- Weighs around 135-150 grams.
- Highly vascular organ.
- Receives 25 % of cardiac output.
- Kidney produces urine – ultrafiltration of blood,
which is then modified by selective resorption and
specific secretion by cells of kidney

6. Kidney tissue consists of to part –
a – outer one called cortex
b – inner one called medulla
MEDULLA –
is made up of triangular area of renal
tissue are called renal pyramids.
RENAL CORTEX –
consist of following –
(a) – medullary rays
(b) – renal columns
(c) – a thin layer of fibrous tissue

7. NEPHRON –
is a structural and
functional .
its consist of –
(a) – renal corpuscle / malpighian
corpuscle
(b) – renal tubule
its consist of –
a – proximal convoluted tubule
b – loop of henle
c – distal convoluted tubule

8. mm

9. NECK –
part between PCT & capsule
made up of cilliated cuboidal epithilium
PCT –
situated in cortex
made up of cuboidal epithilium
microvilli present forms brush border
LOOP OF HENLE –
U – shaped
divided into ascending and descending arms.
thin part made up of squamous epithilium
mostly part present in medulla

10. thick part made up of cuboidal epithilium
DCT –
also present in cortex
made up from cuboidal epithilium.

11. Collecting Tubule and Duct
- Drain urine from nephron to renal
pelvis.
- Lie on medullary ray within cortex.
- Progressively increase in diameter
towards
medulla.
- Simple epithelium - Squamous to
cuboidal.
- Cell boundaries are seen