4. LOBES AND LOBULES
โข Each kidney lobe consists of
โข Medullary pyramid
โข Cortex
โข Renal lobule
โข Portion of kidney containing those
nephrons that are served by a common
collecting duct
Lobule
lobe
5. HISTOLOGY
โข Renal capsule
โข Outer mainly consists of collagen fibers
โข Inner mainly has myofibroblast
โข Myofibroblasts
โข contractile, ฮฑ-smooth muscle actin-
positive cells
โข multiple roles in pathophysiological processes.
Like
โข wound contractions, their persistent presence
in tissues is central to driving fibrosis, making
them attractive cell targets for the
development of therapeutic treatments.
16. MESANGIAL CELLS
โข Found within the glomerulus
โข These cells secrete a matrix of
basement membraneโlike material to
support the structure of the
glomerulus.
17. PROXIMAL CONVOLUTED TUBULE
โข Longest and tortuous part of the
nephron
โข Commences at urinary pole
โข Occupies a major part of the cortex
โข Lined by low columnar epithelium
โข Show brush border
โข Absorb sodium
18. LOOP OF HENLE
โข The thin segment of Henle's loop leads into
the straight part of the distal tubule which is
formed by low cuboidal cells without a brush
border. A few short microvilli are present
โข Epithelial cells in the ascending parts of the
intermediate and straight distal tubule cells
transport chloride ( active) and sodium ions (
passive) out of the tubular lumen into the
surrounding peritubular space.
โข The epithelium can not be penetrated by
water. Consequently, the transport of ions
over the epithelium sets up a gradient in
osmotic pressure, which serves as a driving
force in the further concentration of the urine.
19. DISTAL CONVOLUTED TUBULE
โข Slightly tortuous
โข Lined by simple cuboidal epithelium
โข Absorption of sodium and chloride
20.
21.
22. COLLECTING DUCT
โข Excretory ducts
โข Present in medullary rays
โข Lined by simple cuboidal epithelium
โข Transport urine from the nephron to
the renal pelvis
23. MEDULLARY RAYS
โข Formed of straight tubules and
collecting duct
Medullary rays are cellular structures found in
some species of wood. They appear as radial
planar structures, perpendicular to the growth rings,
which are visible to the naked eye
25. MACULA DENSA
โข Specialized region of DCT
โข Cells are tall columnar
โข Closely packed nuclei
โข Thin and discontinuous basal lamina
โข Release renin
26. JUXTA GLOMERULAR CELLS
โข Present adjacent to macula densa .
โข Epithelioid cells in tunica media
โข Large
โข Internal elastic lamina is absent
27. EXTRA GLOMERULAR MESANGIAL
CELLS
โข Form a cushion of cells between
afferent and efferent arteriole
โข Structurally resemble intraglomerular
cells
โข Functional significance not clear