Urinary system. 2 Kidneys. 2 ureters. Urinary bladder. Urethera. A hemisected vew of the kidney. Kidney. Cortex ---Dark brown and granular. Medulla--- 6-12 pyramid-shape regions (renal pyramids) The base of pyramid is toward the cortex ( corticomedullary border)
The base of pyramid is toward the cortex (corticomedullary border)
The apex (renal papilla) toward the hilum that perforated by 12 openings of the ducts of Bellini in region called area cribrosa . The apex is surrounded by minor calyx.
Is formed of:
(cortical continuation of pyramids).
a- Renal pyramid.
*Each medullary ray with part of the cortical labyrinth surrounding it form kidney lobule.
by thin stroma
and basal lamina.
*It is formed of :
3-Thin limbs of Henle’s loop.
have slit diaphragm
1-Pars convoluta (Proximal convoluted tubule).
2-Pars recta (descending thick limb of Henle’s loop).
It is composed of simple
cytoplasm. The cells have striated
or brush border and lateral
interdigitations. They have
well-defined basal lamina.
1-Descending thin limb.
3-Ascending thin limb.
NB. It is longer in juxtamedullary
nephron than in cortical nephron.
1-Ascending limb of Henle’s loop (low cuboidal epith.).
2-macula densa (tall &narrow cells).
3-Pars convoluta (distal convoluted tubule) formed of low cuboidal epith.
NB. Because distal convoluted are much shorter than proximal convoluted tubules, any section of renal cortex presents many more sections of proximal convoluted tubules.
*Distal tubules drain into collecting tubules.
*Aldosterone hormone increase the active rebsorbtion of sodium from the lumen of tubule into interstitium.
3-Papillary (ducts of Bellini) they open in area of cribrosa.
*They are formed of: a-principle cells.
and b-intercalated cells.
*They are impermeable to water except in presence of antidiuretic hormone.
from the renal papilla of
a renal pyramid.
transitional epith., lamina propria
and smooth muscle.
epith. And lamina propria.
is formed of 2 layers of smooth muscle:
inner and outer longitudinal and
1-Transitional epith. Near the bladder.
2-Pseudostratified columnar epith. And stratified squamous non-keratinized epith.
3-Subepth.fibroelastic CT that contains glands of Littre (mucus secreting glands).
4-Smooth muscle (inner longitudinal and outer circular layer).
1-The prostatic urethra—lined with transitional epith.
2-Membranous urethra---lined with pseudustratified columnar and stratified columnar epith.
3-Penile (spongy) urethra---lined with pseudostratified columnar, stratified columnar and stratified squamous non-keratinized epith.
* Its lamina propria contains mucus secreting glands of Littre.