EPITHELIAL
TISSUES
BY- NIKHIL MAHESHWARI

GROUP OF CELLS WHICH PERFORM A COMMON FUNCTION
ARE CALLED TISSUES
.

BASIC TISSUES
 HUMAN BODY IS MADE UP OF 4 BASIC
TISSUES:
1) EPITHELIAL TISSUE
2) CONNECTIVE TISSUE
3) MUSCULAR TISSUE
4) NERVOUS TISSUE

EPITHELIAL
TISSUE
 LINES EXTERNAL AND INTERNAL SURFACE
OF OUR BODY.
 IT CAN BE ECTODERMAL, MESODERMAL
AND ENDODERMAL IN ORIGIN.

FUNCTION OF
EPITHELIAL
TISSUE
 PROTECTION
 SECRETION
 ABSORPTION
 FORMATION OF GLANDS AND DUCTS

CLASSIFICATION
 EPITHELIUM CAN BE SIMPLE OR
STRATIFIED.

SIMPLE EPITHELIUM
ALL CELLS REST ON BASEMENT MEMBRANE.

SQUAMOUS
EPITHELIUM

 CELLS ARE FLATTENED WITH NUCLEI RAISING A BULDGE IN CELL.
 ALLOWS RAPID EXCHANGE OF SUBSTANCES THROUGH ITSELF.
 EXAMPLE: EPITHELIAL LINING OF ALVEOLI

SIMPLE SQUAMOUS EPITHELIUM

CUBOIDAL
EPITHELIUM

 CELLS ARE LIKE SQUARE .
 HEIGHT OF CELL = WIDTH OF CELL
 NUCLEUS IS CENTRAL AND ROUND
 FUNCTION : ABSORPTION AND SECRETION
 EXAMPLE: EPITHELIAL LINING OF FOLLICLES OF THYROID GLAND

CUBOIDAL EPITHELIUM

COLUMNAR
EPITHELIUM

 HEIGHT OF CELLS > WIDTH OF CELLS.
 NUCLEI IS BASAL AND VERTICALLY ELONGATED
 FUNCTIONS : PROTECTION , SECRETION AND ABSORPTION.
 EXAMPLE: EPITHELIAL LINING OF FALLOPIAN TUBE.

SIMPLE COLUMNAR EPITHELIUM

PSEUDOSTRATIFIED
EPITHELIUM

 PSEUDO: FALSE
STRATIFIED: MULTI LAYERED
 FALSE APPEARANCE OF MULTILAYERED EPITHELIUM.
 SOME CELLS: SHORT , SOME ARE : TALL
 ALL CELLS REST ON BASEMENT MEMBRANE
 EXAMPLE : EPITHELIAL LINING OF TRACHEA

Pseudo stratified epithelium

STRATIFIED EPITHELIUM
MULYILAYERED EPITHELIUM IS KNOWN AS STRATIFIED EPITHELIUM

TRANSITIONAL
EPITHELIUM
 EPITHELIUM WHICH LINES AN ORGAN
AND IS DISTENSIBLE
 EXAMPLE : URINARY BLADDER

TRANSITIONAL
EPITHELIUM

STRATIFIED
SQUAMOUS
NON
KERATINIZED
EPITHELUIM
 MULTILAYERED EPITHELIUM IN WHICH
BASAL CELLS ARE COLUMNAR.
 EXAMPLE: EPITHELIAL LINING OF
ESOPHAGUS

STRATIFIED
SQUAMOUS
NON
KERATINIZED
EPITHELIUM

STRATIFIED
SQUAMOUS
KERATINIZED
EPITHELIUM
 MULTILAYERED EPITHELIUM
 TOP MOST LAYER: KERATIN , VIA WHICH
WATER CAN NEITHER BE EVAPORATED
OR nor BE ABSORPED
 EXAMPLE: EPIDERMIS OF SKIN

Stratified squamous keratinized epithelium