stratified epitheium by dr roomi
TRANSCRIPT
-
8/3/2019 Stratified Epitheium by Dr Roomi
1/16
STRATIFIED EPITHELIUM
BY
DR. MUDASSAR ALI ROOMIDR. MUDASSAR ALI ROOMI(MBBS, M. PHIL.)
-
8/3/2019 Stratified Epitheium by Dr Roomi
2/16
TYPES OF STRATIFIED EPITHELIUM
Where body linings have to withstand wearand tear, the
epitheliaarecomposedofseverallayersofcellsandare
thencalledcompoundorstratifiedepithelium.
Also called as multi-laminarepithelium. Stratifiedepitheliaarenamedafter theshapeofthecells in
the topmost layer.
Typesofstratifiedepitheliaareasfollows:
1. Stratified Squamous Epithelium
2. Stratified Cuboidal Epithelium
3. Stratified Columnar Epithelium
4. Transitionalepithelium
-
8/3/2019 Stratified Epitheium by Dr Roomi
3/16
Stratified squamous epithelium
-
8/3/2019 Stratified Epitheium by Dr Roomi
4/16
Stratified Squamous Epithelium
multi-layered epithelium.
flat, scale-like surface cells.
basal layer is in contact with basal lamina. provideprotectionagainst:
mechanical friction - rubbing and physical trauma
from
external sou
rces chemical damage - environmental and internal
chemicals degrading theepithelial lining
-
8/3/2019 Stratified Epitheium by Dr Roomi
5/16
Stratified Squamous non- keratinized
Epithelium
-
8/3/2019 Stratified Epitheium by Dr Roomi
6/16
Stratified Squamous non- keratinized
Epithelium
The lining of theesophagus is an example ofa
non-keratinizedor "moist" stratified
epithelium. It provides protection to
esophagus from stomachacid.
-
8/3/2019 Stratified Epitheium by Dr Roomi
7/16
Stratified Squamous keratinized
Epithelium
themost apical layers ofcells are dead and losetheir nucleus and
cytoplasm
, insteadcontain a tough,resistant protein calledkeratin.
This specializationmakes theepitheliumwaterproof, so is foundin themammalian skin.
-
8/3/2019 Stratified Epitheium by Dr Roomi
8/16
Stratified Cuboidal Epithelium
-
8/3/2019 Stratified Epitheium by Dr Roomi
9/16
Stratified Cuboidal Epithelium
rare
cube-shaped surface cells.
commonly cellsmakeup two layers
Present in larger ducts of sweat glands,
mammary gland and salivary glands in the
m
ou
th
-
8/3/2019 Stratified Epitheium by Dr Roomi
10/16
Stratified Columnar Epithelia
-
8/3/2019 Stratified Epitheium by Dr Roomi
11/16
Stratified Columnar Epithelia
Rare type ofepithelium.
column-shaped surface cells.
found inlining ofprostatic,membranous andpenileurethra.
-
8/3/2019 Stratified Epitheium by Dr Roomi
12/16
Transitional epithelium
(Urothelium)
-
8/3/2019 Stratified Epitheium by Dr Roomi
13/16
-
8/3/2019 Stratified Epitheium by Dr Roomi
14/16
Transitionalepithelium (also known as urothelium) is atype of tissue consisting ofmultiple layers ofepithelialcells which can contract and expand.
These cells, part of theepithelium, arefound inrenalcalyces, renal pelvis theurinary bladder, in theureters.
Function:
The transitional epithelium cells accommodate
flu
ctu
ation ofvolum
e of the liqu
id in an organ or tu
be,suchas theurinary bladder
protects against the caustic effects ofurine.
Transitional epithelium (Urothelium)
-
8/3/2019 Stratified Epitheium by Dr Roomi
15/16
-
8/3/2019 Stratified Epitheium by Dr Roomi
16/16
FunctionsofEpithelial Tissue Protection : Epithelial cells in the skinprotect underlying tissue from
mechanical injury, harmful chemicals, invading bacteria and from excessive
loss of water.
Sensation: Specialized epithelial tissue containing sensory nerveendings is
found in the skin, eyes, ears, noseand on the tongue.
Secretion: In glands, epithelial tissue is specialized to secrete specific
chemical substances suchas enzymes, hormones and lubricating fluids.
Absorption Certain epithelial cells lining the small intestineabsorb
nutrients from the digestion of food.
Excretion Epithelial tissues in the kidney excrete waste products from the
body and reabsorb needed materials from the urine. Sweatis also excreted
from the body by epithelial cells in the sweat glands.
Diffusion Simpleepitheliumpromotes the diffusion of gases, liquids and
nutrients. Because they form sucha thin lining, they are ideal for the
diffusion of gases (e.g. walls of capillaries and lungs).
Cleaning Ciliated epitheliumassists in removing dust particles and foreign
bodies whichhaveentered theairpassages.