Animal tissues

The animal cells are grouped together to form animal tissues. These tissues vary in their structure, function, and origin.The animal tissues are divided into epithelial, connective, muscular and nervous tissues. 
 

Animal tissues are of four types, viz. epithelial tissue, connective tissue, muscular tissue and nervous tissue.

Epithelial Tissue:

The epithelial tissue forms the covering or lining of most of the organs. The cells of epithelial tissue are tightly packed and form a continuous sheet. There is small amount of cementing materials between the cells and no intercellular space is present. Permeability of the epithelial tissue plays a great role in exchange of materials among various organs it also plays an important role in osmoregulation. All epithelial tissues are separated by the underlying tissue by an extracellular fibrous basement membrane. 

Connective Tissue:

The cells of a connective tissue are loosely scattered in a matrix. The matrix can be a fluid, jelly like, dense or rigid. The nature of matrix depends on the function a connective tissue serves.

Muscular Tissue:

Muscular tissue is composed of muscle cells. Muscle cells are specialized cells which have the capability to contract and expand. Due to contraction and expansion, muscles facilitate various kinds of movements in the body.