Class 9 Animal Tissue

Animal tissue

There are several types of animal tissues and these are often grouped together into the four main classes that for many classes are the following:-

Every category is further subdivided into different subcategories, that we will discuss later in this article:-

1. Epithelial Tissue:- It is arranged in single or multi-layered sheets. It covers the internal and external surface of the body.Epithelial tissue is not supplied by the blood vessels.

It is classified following into the further sub 5 categories according to the distributions:-

A) Squamous Epithelium:- Its cells are thin, flat with clear cytoplasm. A single round nucleus is present in the centre.It  is found in the kidney tubules, bowman capsule etc.

 B) Cuboidal Epithelium:- Cells of this Epithelium a long, broad in shape and they appear like a cube. The cytoplasm is also present in this with centrally located nucleus. It is found in the kidney tubules, ducts of the slavery glands etc.

C) Columnar Epithelium:-

Cells of the epithelium are much longer than and broader and look like a column. It is found in the alimentary canal, uterus, urine tubes. 

D) Ciliated Epithelium:- This epithelial possesses thin hair-like projections, called cilia on the outer surface. This epithelium help in the movement of the substances.

E) glandular epithelium: The cells of the epithelium are columnar in shape. some of the cells become modified to secrete mucus. it is seen in the intestine and the other parts of the alimentary canal.

Functions of Epithelial tissue 

1.  It covers the body and protect against any mechanical injury, effects of pathogens such as virus and the bacteria.

2.  It protects the internal organ by forming a lining on their surfaces like the alimentary canal reproductive tract.

3.  In lung alveoli epithelium help in the diffusion of gases between the air and the blood.

4.  In the intestine epithelium allowed the absorption of water and digested food. 

Muscular Tissue:-

It is a soft tissue that makes up the muscles in animals and gives the ability of muscles to contract. These muscles are highly contractile and are responsible for the movement of the body.

 Muscle tissues vary with function and location in the body. In mammals the three types are:

 1. Striated Muscles or Voluntary Muscles:-

These muscles are formed by elongated and cylindrical cells.

These muscles mainly attach to the skeletal system via tendons to maintain posture and control movement for example contraction of the biceps muscle. 

Main functions of striated muscles

 1.     Locomotion in organism and movement of limbs.

2.     Inhalation and exhalation and movement of limbs.

          3.     Blinking of eyes voluntary actions and movement of the body. 

 2. Smooth Muscles.

This kind of muscles is formed by the spindle-shaped, elongated, uninucleate cells. Only the longitudinal fibrils are present in the form the walls of voluntary organs. These muscles are not in the control of animals so that's why they are known as the involuntary muscles.

Functions of smooth muscles:-

1.     Movement of the food through oesophagus by causing the peristaltic movement.

2.     Removal of urine from the bladder occurs by contraction of the smooth muscles.

3.     Focusing the object and adjustment of the amount of light entering the eye occur because the contraction and relaxation of smooth muscles

 

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 3. Cardiac Muscle Tissue:-

Cardiac muscle tissue is found only in the heart where cardiac muscles contract and relax just to pump blood throughout the body and maintain blood pressure.

Functions of cardiac muscles

The rhythmic contraction and the relaxation continuously in the cardiac muscle causes the pumping of blood.

4. Connective Tissue:-

The connective tissue of the tissue which connects one body parts with another body part. Connective tissue performs many functions. It binds and connects the other tissue of our body. It provides support to the body like bone and the cartilage. it helps to repair the wear and tear of the body. Bone, cartilage, blood, tendon and ligament are the kind of connective tissue.

Functions of adipose tissues

1.  Fat storage tissue .

2.  Shock absorber tissue.

3.  Insulating tissue reigns extremely cold surrounding.

 

A) Bone:-

            It is rigid tissue that protects and bind all the body organs.

B) cartilage:-   

                  It is also the specialised connective tissue which is hard but rubber-like padding that covers and protects the ends of long bones at the joints and nerves.

Difference between the bone and the cartilage

Bone	Cartilage
1.  It is strong and inelastic. 2.  Bone cells are supplied by the nerves and blood vessels. 3. Marrow cavity is present in many bones. 4.  The matrix contains both organic substances and inorganic substances like mineral phosphates and carbonates.	1. It is soft flexible and elastic.  2. No blood vessels for the nerve supply is seen.  3. Marrow cavity is absent. 4.  Matrix contains only organic substances.

C) Blood

 Blood is a bright red coloured fluid connective tissue that circulates in the whole body.It is made up of the two components plasma(fluid part) and blood corpuscles(solid part).

Plasma - Non-living part (60%of total blood)

Functions of blood:-

1.     Transportation of substances such as gases nutrients metabolic waste between the different body parts.

2.     Clotting of blood.

3.     Maintenance and the regulation of the body temperature.

4.     Production of antibodies and the antitoxin against the pathogens which plays an active role in the body defense. 

Difference between voluntary and involuntary muscles:-

Voluntary muscles	Involuntary muscles
1.     These functions according to the will power of the animal.  2.     They get easily fatigue after sometime.  3.     Their working is controlled by the brain. 4.     For example skeleton muscles.	1.     These do not function as per the will of the animals.  2.     No fatigue occur in these in whole life.   3.     Their working is not controlled by the brain. 4.     For example cardiac muscles.

D) Tendon:-

            It is a very thick and strong connective tissue mainly composed of white collagenous fibres. Tendons help to Join The Muscles To The Bone.

 E) Ligament:-

                  It is formed by flat cells, which are present in between the fibres ligament which joins one bone to another bone at the joints and also hold them in position.

Difference between Tendon and ligament

Tendon	Ligament
1.     There are tough in elastic tissues. 2.     The joint skeletal muscle with bone.	1.     These are strong and flexible tissues. 2.     These join two bones at joint.

4. Nervous Tissue:-

              These are specialised tissue which is Controls the body's movements, sends and carries signals to and from the different parts of the body, and has a role in controlling body functions such as digestion. It is made up of a) nerve cell and c) nerve fibre.

The neurone or nerve cell is the longest cell and it is present in the brain, spinal cord and sense organ. It is made up of three parts cyton, dendrites, axon.

1. Cyton (Cell Body)

The cell body contains a nucleus of the nerve cell. it consists of granules, neurofibrils which are responsible for the transmission of impulses from one neurone to another.

2. Dendrites:- It is a small branch projection growing out of the cyton. The main function is to transmit the impulses to the cell body. Large dendrites are called Dendron.

3. Axon:-

Axon is a long uniform and uniformly thick cylindrical process growing out of a cell body. its main function is to transmit the nerve impulses away from the cell body.

Notes prepared By:- GAGANDEEP KUMAR