2. kidney
There is a depression on the medial
border of kidney called hilum, through
which renal artery, renal veins, nerves
and ureter pass.
3. DIFFERENT LAYERS OF
KIDNEY
Components of kidney are arranged in
three layers:
1. Outer cortex
2. Inner medulla
3. Renal sinus.
4.
5. 1. Outer Cortex
Cortex is dark and granular in
appearance. It contains renal corpuscles
and convoluted tubules.
At intervals, cortical tissue penetrates
medulla in the form of columns, which
are called renal columns or columns of
Bertini.
6. 2. Inner Medulla
Medulla contains tubular and vascular
structures arranged in parallel radial lines.
Medullary mass is divided into 8 to 18
medullary pyramids.
Broad base of each pyramid is in contact
with cortex and the apex projects into
minor calyx.
7. 3. Renal Sinus
Renal sinus consists of the following structures:
i. Upper expanded part of ureter called renal pelvis
ii. Subdivisions of pelvis: 2 or 3 major calyces and
about 8 minor calyces
iii. Branches of nerves, arteries and tributaries of
veins
iv. Loose connective tissues and fat.
8. Nephron
Functional and structural unit of the
kidney
Approximately 1 million
nephrons/kidney
Each nephron has two components
○ Vascular component
○ Tubular component
10. Hollow, fluid-filled tube
single layer of epithelial cells
Components
Bowman’s capsule
Proximal convoluted tubule
Loop of Henle
Descending limb (thin)
Ascending limb (thin and thick part)
Distal convoluted tubule
Collecting duct or tubule
Juxtaglomerular apparatus
11. Bowman’s capsule – expanded double walled
invagination that cups around the glomerulus to
collect fluid from the glomerular capillaries.
From bowman’s capsule, filtered fluid passes
into PCT.
From PCT, fluid passes into loop of Henle [LH].
12. Nephron (Vascular
component)
Dominant part is the glomerulus
Glomerulus is a tuft of glomerular
capillaries.
large amounts of fluid & solutes are filtered
from the blood.
13.
14. Vascular Component
Renal Artery enters the kidney and forms afferent
arteriole, which supplies each nephron.
Afferent arteriole delivers blood to the
glomerulus.
Glomerular capillaries rejoin to form another
arteriole – the efferent arteriole.
The blood that was not filtered in the glomerulus
goes to efferent arteriole.
15. Efferent arteriole gives second set of capillaries,
the peritubular capillaries, which supply the
renal tissue and are important in exchange with
tubular system.
(Peritubular means around the tubular system)
Peritubular capillaries rejoin to form venules,
that drain in renal vein.
16. Nephron
Two types of nephrons
Distinguished by location and length
of their structures
Juxtamedullary nephrons
Cortical neohron
