Animal tissues and its classifications

Animal Tissues

Animal tissues are divided into four major types.

Epithelial tissues

Connective tissues

Muscle tissues

Nerve tissue

These four types of the animals tissues are subdivided into several types according to their location and functions. Some of them will be explained in brief.

Epithelial Tissues

These tissue are found as outer most layer of an organ and as a lining of a body invagination and in tabular parts. These cells are flattened and elongated in structure. They may be form one or more layers of epithelial tissue of skin called squamous epithelium. They provide protection to the body. Some cells are in cubicle shape and they are called epithelial cells. They usually line the glandular ducts and they provide help in the production of cell secretions. Some cells are small and elongated and are found at different places in the inner surface of the organs. They are called columnar epithelial cells e.g. In stomach, cells of gastric glands secrete the gastric juice. Some cells have cilia at their free surface, which are columnar cells. These are called ciliated epithelial cells e.g. cells which are present in trachea. Some material like mucus are expelled due to the movement of cilia.

Connective Tissues

This is composed of semi fluid matrix which contains a variety of cells and fibers. This is the major tissue of body which is used for supporting and some of its other functions such as packing and binding of structures. They protect against the microbial invasion and also helps in the production of blood cells. There are two types of connective tissues. Fatty tissue and tendons are the main examples of soft connective tissues. Cartilage and bones are the examples of hard connective tissues. Blood is also a special connective tissue with cells, they are suspended in a fluid medium. They transport material in the all parts the body.

Muscular Tissues

This tissue is made up of contractile cells and fibers. Each fibers in the muscle are elongated cell, which has ability to contract and relax when we need it. Due to these tissue, our body is able move and our body parts can easily move. In our body, there are three types of tissue are found.

Skeletal Muscles

Smooth Muscles

Cardiac Muscles

Skeletal Muscles

These muscles are attached to the cartilage and bones. These are appears as a striped fibers under a microscope. These are called striped or striated muscles. i.i These are voluntary muscles, and produce powerful and rapid contractions and helps our arms and legs to move.

Smooth Muscles

These are found around hollow structures such as blood vessels and guts. They produces a slow contractions but this contraction is not a fatigue. They are composed spindle shaped. and not a straight muscles. They a involuntary and they are controlled by the nervous system.

Cardiac Muscles

These muscles are only found in the heart. These are composed of branched fibers and they have ability to contract, but do not fatigue. these are involuntary in action. These are controls by brain.

Nervous Tissues

They are composed of nerve cells, which are called neurons. Each neuron composed of cell body with dendrites and axons. They produce nerve message called impulse and are also connected to various parts of the body. These are found in the nerves and in the central nervous system e.g brain and spinal cord.