ANIMAL TISSUES

Epithelial tissue

  • The covering or protective tissue in animal body are epithelial tissue, covering most organs and cavities it forms a barrier to keep different body systems separate.
  • The skin, the lining of the mouth, the lining of blood vessels, lung alveoli and kidney tubules are made up of epithelial tissue.
  • Cells of epithelial tissue are tightly packed and form a continuous sheet having small amount of cementing material between them and almost no inter-cellular spaces.
  • All epithelium are separated from the underlying tissue by an extracellular fibrous basement membrane.

Epithelial tissue Classification

i) Squamous epithelial tissue 

  • Squamous epithelial tissue consists of a layer of thin flat cells.
  • It is present in the linings of blood vessels, lungs, mouth, oesophagus etc.
  • The skin has several layers of epithelial cells. This tissue is called Stratified squamous tissue.

ii) Columnar epithelial tissue :-

  • Columnar epithelial tissue consists of tall pillar like cells.
  • It is present in the walls of the intestine.
  • The columnar epithelial tissue in the respiratory tract has hair like projections called cilia.
  • This tissue is called Ciliated columnar epithelial tissue.

iii) Cuboidal epithelial tissue :-

  • Cuboidal epithelial tissue consists of cone shape cells having a basement membrane.
  • It forms the lining of kidney, tubules and ducts of salivary glands and provide mechanical support.

iv) Glandular epithelial tissue :-

  • Sometimes epithelial tissue folds inwards and forms a multicellular gland which secretes substances.
  • This tissue is called Glandular epithelial tissue.

NCERT Solutions Class 9 Science Tissues

Connective tissue

  • The cells of a connective tissue are loosely packed and embedded in inter cellular matrix, this matrix may be jelly like, fluid, dense or rigid.
  • Blood is a type of connective tissue.

i) Blood :-

  • Blood contains a fluid matrix called plasma which contains red blood cells (RBC), white blood cells (WBC) and platelets.
  • The blood transports gases, digested food, hormones, waste materials etc.

ii) Bone :-

  • Bone is a hard and strong tissue
  • It consists of cells which are embedded in a hard matrix containing calcium and phosphorus compounds.
  • Bone forms the framework of the body and supports the body and the main organs.

iii) Ligaments :-

  • Ligaments are flexible tissues which joins bones together and helps in movements.

Ligaments

iv) Tendons :-

  • Tendons are fibrous tissues which joins muscles to bones and helps in movements.

v) Areolar tissues :-

  • It fills the space between skin and muscles, inside the organs, around blood vessels etc.
  • It helps to repair the tissues.

vi) Adipose tissue :-

  • Adipose Tissue is found below the skin and between internal organs.
  • It contains fats and helps to store fats.

Muscular tissue

Muscular Tissue
Muscular Tissue
  • Muscular tissue contains elongated cells are called muscle fibres and is responsible for movement in our body.
  • Muscular tissue contains special proteins called contractile proteins which can contract and relax.
  • Muscles that move by our conscious will are called voluntary muscles for example muscles present in our limbs and are also called skeletal muscles .
  • Muscles which do not move under our will are called involuntary muscles.

i) Striated muscles :-

  • Striated muscles are voluntary muscles having light and dark striations.
  • The cells are long, cylindrical and are multinucleated.
  • They are also called skeletal muscles because they are attached to bones.
  • They help in voluntary movements of the body.

ii) Unstriated muscles ( Smooth muscles) :-

  • Unstriated muscles are involuntary muscles having no striations.
  • The cells are long and spindle shaped and are uninucleated.
  • They are present in alimentary canal, blood vessels, bronchi of lungs, iris of eye etc.
  • They help in involuntary movements.

iii) Cardiac muscles :-

  • Cardiac muscles  are involuntary muscles having faint striations.
  • The cells are long, cylindrical, branched and multinucleated.
  • They are present in the heart and helps in the contraction and relaxation of the heart.

Nervous Tissue

  • Nervous tissue is highly specialized for responding and transmitting stimulus very rapidly.
  • Nervous tissue have cells called neurons containing a cell body with a nucleus and cytoplasm
  • Each neuron has single long part called axon and many short branched part called dendrites.
  • The combination of functions of nerves and muscle tissue is fundamental to animals.

NCERT Solutions Class 9 Science Tissues

Click Here for Quiz on Tissue 

Read the First part of the lesson on Plant Tissue here 

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