2nd Lecture on the Histology of Urinary System by Dr. Roomi
-
Upload
mudassar-roomi -
Category
Documents
-
view
226 -
download
0
Transcript of 2nd Lecture on the Histology of Urinary System by Dr. Roomi
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
1/19
Histology
of Urinary System
By
Dr. Mudassar Ali Roomi (MBBS, M.Phil)
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
2/19
Parts of nephron
Bowmans capsule
Renal corpuscle= Bowmans
capsule+ glomerulus Proximal tubule = PCT+ PST
Intermediate tubule = thin
segment
Distal tubule = DST + DCT
Loop of Henle= PST + DST+
Thin segment
2
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
3/19
Proximal
convoluted tubule
(PCT)
PCT is similar histologically to PST.
Simple Cuboidal or low columnar epithelium
Longer (14mm) than the distal convoluted
tubule. So,more frequently seen in sections
of renal cortex.
diameter= 50-60 um
Eosinophilic cytoplasm.numerousmitochondria
Cell apex has abundant long microvilli which
form a prominent brush borderfor
reabsorption.
Apical part of cell also show a lot of vesicles.
Prominent lateral interdigitation of cells.
Basal striations of the cells: Numerous
mitochondria compartmentalized in the
basal region by extensive infoldings of the
basal plasma membrane.
Because the cells are large, each transverse
section of a proximal tubule typically
contains only 3-5 rounded nuclei. Function: ?
3
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
4/19
4
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
5/19
Loop of Henle
U-shaped structure.
Several parts
thick, descending portion
(PST)
thin segment (dia= 15 um)
Thick ascending segment
(DST)
Thin segment is lined by
simple squamous epithelialcells having a few microvilli.
5
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
6/19
6
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
7/19
Distal convoluted tubules (DCT)
It is much shorter in length(5mm)
has a wider lumen than PCTbecause the cells are low inheight.
DCT is similar histologically toDST.
Simple cuboidal cells (6-8 cellsper cut section)
cytoplasm= faintly acidophilic
Have no brush border and are
smaller than the cells of proximaltubules.
Function:?
7
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
8/19
8
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
9/19
PCT Vs DCT
9
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
10/19
COMPARISON
PCT
1. Longer, so more cut sections
2. More outer diameter
3. Less diameter of lumen4. 3-5 cells per section
5. Low columnar cells
6. More eosinophilic cytoplasm
7. Brush border present8. Prominent lateral
interdigitations of cells-
present
DCT
1. Shorter, so less cut sections.
2. Less outer diameter
3. Wider lumen4. 6-8 cells per section
5. Low cuboidal cells
6. Less eosinophilic cytoplasm
7. No brush border8. Lateral interdigitations of
cells not prominent
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
11/19
Collecting Tubules & Ducts
The collecting tubules are lined
with cuboidal epithelium.
Cells of the papillary collecting
ducts of Bellini are columnar
Centrally placed dark stainingnucleus
Cytoplasm stains faintly
No brush border
No basal striations
Function=?
11
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
12/19
12
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
13/19
Juxtaglomerular
apparatus (JGA)
Specialized structure
Made by The initial, straight part of the distal
tubulemaking contact with The vascular
pole of the renal corpuscle of its parent
nephron.
Macula densa
Thickened part of the distal tubules that is in
contact with the arterioles of renal corpuscle.
columnar and more closely packed.
Apical nuclei, basal Golgi complexes.**
Acts as a Sensor of osolarity: A more
elaborate and varied system of ion channels
and transporters.
Juxtaglomerular Granular (JG) cells
Present adjacent to the macula densa, in thetunica media of the afferent arteriole.
Modified smooth muscles (epitheloid cells)
cells with secretory nature (renin)
More rounded nuclei, rough ER, Golgi
complexes and zymogen granules
Lacis cells
extraglomerular mesangial cells Function?
13
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
14/19
14
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
15/19
15
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
16/19
16
comparison
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
17/19
17
comparison
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
18/19
HOW TO DRAW KIDNEY!
-
7/31/2019 2nd Lecture on the Histology of Urinary System by Dr. Roomi
19/19
Ureter- how to draw it!