Question

Describe the structure and function of different types of epithelial tissues. Draw the diagram of each type of epithelial tissue.

Accepted Answer

Epithelial tissue is a tissue that covers most organs and cavities of the body. Depending upon the shape and function of the cells, the epithelial tissues are classified as follows :
1. Simple epithelial tissue:
a) Squamous
b) Cuboidal
c) Columnar
2. Stratified Epithelial Tissue

1. Simple Epithelial Tissue

(a) Squamous epithelium:

1. Squamous epithelium is made up of thin, flat, irregular shaped cells which fit together like floor tiles to form a compact tissue. Squamous epithelium is also known as tessellated and pavement epithelium.

2. It protects the underlying parts of the body from mechanical injury, entry of germs, chemicals and drying.

(b) Cuboidal epithelium:
1. The cuboidal epithelium consists of cube-like (cubical) cells which are square in section, but the free surface appears hexagonal.
2. It helps in absorption, excretion and secretion. It also provides mechanical support.

(c) Columnar epithelium:
1. The cells of columnar epithelium are taller than broader (i.e., pillar-like). The cells are arranged side by side like a column. The nucleus is oval and is present at the base of the cell.
2. Its main functions include absorption and secretion.

2. Stratified epithelial tissue:
1. It is composed of several layers of cells. The innermost layer rests on the basement membrane called the germinative layer. New cells are produced from this layer by mitosis.
2. Their primary function is to protect the underlying structure from mechanical wear and tear.

A neat labelled diagram of the simple and stratified epithelial tissues.

A neat labelled diagram of the stratified epithelium.

Dr Yash Pal and Dr Joginder Singh Solutions for Chapter: Tissues, Exercise 7: Long Answer (LA) Type Questions

Dr Yash Pal Biology Solutions for Exercise - Dr Yash Pal and Dr Joginder Singh Solutions for Chapter: Tissues, Exercise 7: Long Answer (LA) Type Questions

Questions from Dr Yash Pal and Dr Joginder Singh Solutions for Chapter: Tissues, Exercise 7: Long Answer (LA) Type Questions with Hints & Solutions

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