3. Animal Tissues

Animal Tissues

Types of Animal Tissues

 

                                                                                     Types of Animal Tissues

1. 1. Epithelial Tissue

• They are the protective tissues of the human body. They cover many organs and cavities that are present inside the body.
• Where are the epithelial tissues found in the human body?

1. 1. The lining of the blood vessels
   2. The lining of the mouth
   3. Kidney tubules
   4. Skin
   5. Lung alveoli

 Structure and functions of the epithelial tissues -

 

1. 1. The main function of the epithelial tissues is to act as a barrier and separate different organs and systems from each other.
   2. There is no space between the cells of epithelial tissues
   3. The cells are permeable. This makes it possible for them to exchange materials between different parts of the body and also between the body and the external environment.
   4. The epithelial tissues remain separated from the tissues beneath them because of a thin membrane over them.

                                                                 Types of Epithelium

Different types of epithelium tissues	Simple Squamous	Stratified Squamous	Columnar	Ciliated Columnar	Cuboidal	Glandular
Structure	They have delicate cell lining and possess a flat thin structure	The epithelium Squamous cells are arranged in several layers	They are the column-like shape tissues	Columnar epithelial tissues which have Cilia present on them	They are cube-shaped cells which are involved in absorption and secretion.	These are special gland cells that can secrete substances
Found in	Alveoli and bowman’s capsule- nephron in kidney	Skin	Intestine	Respiratory system	Kidney tubules	Sweat glands in the skin

 

Connective Tissue

Structure and function of connective tissues

• • They are loosely bound cells present in an intercellular Matrix.
  • This matrix can be of different types – Dense, Rigid, Fluid or Jelly-like.
  • Depending upon the functionality of the connective tissue, the nature of the matrix varies in them.

 

 Blood

• The main function of blood is to transport gases, food, waste materials and hormones in the body.
• Therefore, blood has a fluid Matrix present in it which is called Plasma.
• The plasma contains the red blood cells, the white blood cells and blood platelets.
• The RBC have hemoglobin pigment which carries oxygen to tissues.
• White blood cells fight diseases and platelets are involved in clotting of blood when injured.
• The plasma also contains proteins and hormones in it.

Bones

• Bones form a framework of the body over which the muscles are wrapped together.
• The bone tissue is strong and inflexible in nature.
• Therefore, the bone cells are present in a rigid matrix which is formed from calcium and phosphorus.

Cartilage

• Cartilage is present over the joints of the bones and provides them with a smooth structure.
• For Example, in the nose tip and ear pinna, trachea, larynx.
• They contain solid matrix made of protein and sugar. They have homogenous matrix.
• It provides support and flexibility to various parts of our body.

Ligaments

 

• A ligament connects two bones together.
• It has an elasticity which facilitates the connection.
• The cells of ligaments have a little matrix.

Tendons

• The tendons tissues are responsible for connecting bones and muscles together.

• They have limited flexibility but very great strength.

Areolar

• This tissue acts as a filter in between the spaces present inside the organs of the body.
• It helps in repairing other tissues as well.
• It is found in the skin and bone marrow.

Adipose

• Fats are stored in our body in the adipose tissues.
• They are found below the skin and between the organs of the body.
• Provides cushioning to the organs.

Muscular Tissue

• It is made up of muscle fibers which are long cells.
• It allows movements in our body.

• How muscles can cause movement?

They contain special proteins called Contractile Proteins. These proteins cause contraction and relaxation of the muscles.

• There are two kinds of muscles found in our body - Voluntary Muscles and Involuntary Muscles.

Striated/ Skeletal/ Voluntary muscles	Smooth/ Unstriated/Involuntary muscles
We can move them according to our own will	We cannot start or stop the movement of involuntary muscles.
They are also called Skeletal Muscles as they are attached to the bones.	They also called Smooth Muscles.
They are also called Striated Muscles because of the presence of dark and light bands over them	They are also called Unstriated Muscles because they do not have any light or dark bands on them.
The cells of voluntary muscles have more than one nucleus, they do not have any branches, and have a long cylindrical structure.	The cells of the involuntary muscles are long and have pointed ends.
For Example, Muscles of our hands and legs.	For Example, The muscles in the alimentary canal and the Iris of our eyes.

 

Cardiac Muscles

• These are special kinds of involuntary muscles.
•  
• The muscles of the heart are called Cardiac Muscles they perform rhythmic contraction and relaxation throughout our life.
• They are cylindrical in shape; they have branches and there is a single nucleus.
• Cardiac muscle consists of individual heart muscle cells connected by intercalated discs to work as a single functional organ