Basic tissues are of 4 types……
1.Epithelial tissue
2.Connective tissue
3.Muscle tissue
4.Nervous tissue
Epithelial tissue
Definition
Epithelium consists of sheets of cells that
cover the external surfaces of the body, line
the internal cavities, forms various organs and
glands and line their ducts.
Epithelium
Simple
Epithelium
Simple Stratified
Squamou
s
Cuboidal
Non
ciliated
columnar
Ciliated
columnar
Columnar
Brush
border
columnar
Squamou
s
Non
keratinized
keratinized
Transitiona
l
Cuboidal
Columnar
Pseudo-stratified……..????
Squamous epithelium:
Nuclei produce bulging of the cell surfaces.
Mesothelium: covering of abdomen,heart,lungs
Endothelium: lumen of blood vessels, lymphatic vessels
E. g : Alveoli of the lungs.
Functions :-
Diffusion, secretion, absorption.
Simple squamous epithelium seen under
microscope
Cuboidal epithelium :-
Nucleus is rounded and placed at the center.
e. g : follicles of thyroid gland, ducts of glands,
outer surface of ovary
Columnar epithelium:-
•Cells are elongated ,with elongated nucleus at the base.
•Columnar epithelium without cilia or microvilli .
•E. g:-mucous membrane of stomach
Columnar epithelium with cilia (hair like projections):
E. g:-respiratory tract, uterine tube.
Columnar epithelium with microvilli arranged regularly
(striated border).
E. g:-small intestine
Columnar epithelium with microvilli arranged in irregular manner
(brush border)
E. g:-gall bladder
E. g : mucous membrane of stomach
Simple columnar epithelium seen under
microscope
Pseudo stratified columnar epithelium:-
Ciliated or non ciliated. Cells are present on the basement
membrane are of different height.
Nucleus of cells are at different levels.
E. g:-nasal cavity, trachea (ciliated)
Functions:-cilia of the cells trap dust.
Ciliated pseudo stratified columnar epithelium
Seen under microscope
Stratified epithelium
Multilayered
Wear and tear
Types……….?????
Stratified squamous non keratinized
epithelium
Stratified squamous non keratinized
epithelium
Basal columnar cells
3-4 layers of polyhedral cells
Surface layers of squamous cells.
E.g. oral cavity, esophagus, vagina
Stratified squamous keratinized epithelium
Stratified squamous keratinized epithelium
Basal columnar cells
3-4 layers of polyhedral cells
Surface layers of squamous cells
Dead cells or keratin
E.g. skin
Transitional epithelium (urothelium)
Function:-protection and distension