Epithelial Tissue (Animal tissue)

Watch full video

INTRODUCTION

Cells are the body's smallest functional units they are grouped together to form tissues, each of which has specialized functions. e g.blood, muscle

Study of tissues is called histology.

Tissues are grouped together to form organs e.g heart, stomach, brain.

Organs are grouped together to form system, each of which performs a particular functions.eg digestive system.

TISSUES

DEFINITION:

Tissue is a collection of cells which have similar structure and perform relatively common functions.

TYPES OF TISSUES

TISSUES

Connective tissues

Muscular tissues

Epithelial tissues

Nervous tissues

EPITHELIAL TISSUES

CHARACTERISTICS

Cells are closely packed without intercellular spaces

 Lie on membrane

LOCATION

Found covering the body and lining cavities and tubes. Outer and inner linning of most of the body organs such as gastrointestinal tract(GIT), urinary tract, blood vessels, heart chambers uterus.

Found on the entire exposed surface of the body such as skin.

Also found in glands

FUNCTIONS OF EPITHELIAL TISSUES

Role of defense and protect body organs

Secret gastric juice in stomach. 

Absorb digested food in intestine.

Removes waste as sweat in skin.

EPITHELIAL TISSUE

SIMPLE EPITHELIUM

STRATIFIED EPITHELIUM

SIMPLE EPITHELIAL TISSUE

Consists of a single layer of identical cells.

Found on absorptive or secretary surfaces.

Divided into three main types.

TYPES OF SIMPLE EPITHELIUM TISSUE

Squamous

Cuboidal

Columnar

TYPES OF STRATIFIED EPITHELIAL TISSUES

STRATIFIED EPITHELIAL TISSUE

1. Stratified squamous epithelium

2. Transitional epithelium

Keratinised epithelium

Non keratinised epithelium

KERITINISED SQUAMOUS EPITHELIUM

Found on dry surfaces subjected to wear and tear.

Consists of dead epithelial cells that have lost their nuclei and contain the protein keratin.

Sites

Skin, hairs and nails

NON-KERATINISED EPITHELIUM

Protects moist surfaces subjected to wear and tear and prevents them from drying out.

Sites

Conjunctiva of the eyes, the lining of the mouth, the vagina.

TRANSITIONAL EPITHELIUM

Composed of several layers of pear shaped cells which are very elastic and have the capacity of dividing themselves.

Sites

Lines several parts of the urinary tract including the bladder.

By : @ummedsaini_