Tissues

Tissues:- Group of cells that are similar in structure and functions is called tissue.

There are classified into four catagory according to their function and structure.

1) Epithelial tissue

2) Connective tissue

3) Muscle tissue

4) Nervous tissue

Epithelial Tissue

Epithelial Tissue :- The epithelial tissue is a type of body tissue that forms the covering on all internal and external surface of your body lines, body cavity and hollow organs and is the major tissue in glands.

 Function of the epithelial tissue

* Protection:- Epithelial tissue protects several aspects of your body. For example:- Skin protect from sunlight and bacteria and physical damage.

* Secretion:- Epithelial tissue in your glands can secrete enzymes, hormones and fluids.

* Absorption:- The epithelial tissues lining of your internal organs can allow the absorption of certain substances. For Example:- Intestines absorbs nutrients from the food you eat.

* Filtration:- Epithelial tissue in your kidneys filters your blood. Respiratory track filters out dirt.

Charactristics of epithelial tissue

* Epithelial tissue always found in internal and external surface of body, lining of tubes and surface of cavity and gland.

* Every cell present in a basement membranes. 

* There are space between each cell that is called interstitial space that filled with matrix.

Classification of Epithelial Tissue

Simple Squmous Epithelial Tissue:-  Simple squmous epithelial tissue is single layer of flattened cell. It act as as absorption and filtration. It found in  walls of capallaries, air sacs in lungs, form serous membranes in body cavity.

Cuboidal Sipmle Epithelial Tissue:- Cuboidal simple epithelial tissue is single layer of cube shaped cells. It secretion and transportation in glands and filtration in kidneys. They are found in glands and ducts (pancreas & salivary), kidney tubules and covers ovaries.

Simple Columnar Epithilial Tissue:- Simple columnar epithilial tissue is elongated layer of cells with nuclei at same level. It help to absorption, protection and secrectio. 

* When open to body cavities called mucous membranes.

Special Features

* Microvilli, bumpy extension of apical surface, increase surface area and absorption rate.

* Goblet cells, single cell glands, produce protetive mucus.

Location:- Linings of entire digestive track

Simple Ciliated Epithilial Tissue:- Ciliated epithelial tissue is a thin tissue that has hair-like structure on it. These hairs called cilia, move back and forth to help move particle out of our body. We find cilliated epithelial tissue in respiratory track and in fallopian tubes of women.

Stratified Squamous Epithelial:- This type of epithelial tissue is multilayer tissue. It has protective function. for exapmle Protection against microorganism and water loss. The outer layer of skin ( The epidermis) is made of stratified squmous epithelial cells.

Transitional epithilial : A Transitional epithelial is made up of several layers of cells that become flattened when stretched. It lines most of your urinary track and allows your bladder to expands.

Connective Tissue

It is most aboundad tissue in body. It is supporting tissue that helps to bind other tissues together.

Function of connection Tissue

* Binding and support

* Transportation

* Protection

* Insulation

* Medium for Exchange nutrient and waste product

Component Of Connective Tissue

Fibroblast:- Fibroblast is main cell which manufactres both the fibers and the ground substance. It is repair wound.

Fat Cell:- Fat cell are aboundad in adipose tissue.

Macrophases :- Macrophases are irregular cells. They are important in body's defence mechanism and help to ingest dead or dying cell, Bacteria and other foregien bodies.

Lucocytes:- Leukocytes/WBC  are also present in connective tissue and secreting antibodies (by plasma cell) play an important role in tissue defence.

Mast Cell:- It is vandeting cell in connective tissue which act major in defence of human body & Protect from foreign body this cell mostelly occur in lymph nodes and spleen.

Plasma Cell:- Secreating antibody

* Fibers:- The fibers are theread like structure. The Fibers are collagenous fibers, elastic or reticular fibers.

Collagenous fibers:- Collagenous fibers are white colour and very thick thread like structure.

Elastic Fibers:- Elastic Fibers are yellow colour and thick thread like structure. It is provide Flaxibility and Found Branches in his structure.

Reticular fibers:- Reticular fibers are black and fine thread like structure.

Classification of Connective Tissue

Dense Connective Tissue

Dense Connective Tissue is a type of connective tissue with fibers as its main matrix element. It has less amount of cell and more matrix.

It has Two type of Dense connective tissue

* Regular connective Tissue

* Irregular Connective Tissue

Regular Connective Tissue:- 

Tandon:- Tendon is connect Muscles and bone.

Ligament:- Ligament is connect bone to bone.

Irregular Connective Tissue:-

Elastic Tissue:- Elastic Tissue consists of branching elastic fibres e.g. Lungs tissue, Trachea, Bronchi, etc.

Loose Connective Tissue

Loose connective tissue is a type of connective tissue. it has more amount of cell and less amount of matrix.

Loose Areolar Connective Tissue:- It is Most generalized of all connective tissue. It has more amount of fibroblast and some amount of macrophase. It provide strength and support.

Adipose Tissue:- Adipose tissue consist of fat cells (adipocytes) and Most connective tissue. It found in gland. 

Reticular Tissue:- Reticular connective tissue consist of a network of interlacing reticular fibers and reticular cells. It provide protection and filteration.

Specilised Connective Tissue

Bone:- Bone is the type of connective tissue which Composed by osteoclast, osteoblast and osteocyte that provide structural support and framwork to body.

Blood:- Blood is a fluid connective tissue that consists of plasma, blood cells and platelets. It circulates throughout our body delivering oxygen and nutrients. It makes up 8% (5-6 liter) our body weight. 

Cartilage:- Cartilage is a stronge flexible connective tissue that protect joint and bone. It act as sock absorber through out body. Cartilage at end the bone reduceses friction and prevent them from rubbing. 

Lymph:- Lymph is a clear Clourless fluid which act in defence system of human body and maintain body fluid.

Muscle Tissue

Muscle tissue is composed of cell that have the special ability to contract or relax in order to the body part.

Classification of Muscle tissue

* Skeletal Muscle

* Smooth Muscle

* Cardiac Muscle

Skeletal Muscle:- Skeletal muscle also called voluntary muscle is a muscle tissue that is attached to the bone and is involved in the functioning of different parts of the body. It many branches, multinuclear cell and cylendrical shape. It procide streingth.

Smooth Muscle:- Smooth Muscle is a type of non-straited muscle that is found in the walls of hollow organs and blood vesseles. It has no branche, unicellular cell and spindle shape. It also called incoluntary muscle.

Cardiac Muscle:- Cardiac muscle or myocardium, is a specialized type of muscle tissue, which contracts and releases involuntary, is responsible for keeping the heart pumping blood around the body.

Nervous Tissue

Nervous tissue is found in the brain, spinal cord and nerves. It is responsible for coordinating or controlling.

    Or

Nervous tissue is found in the brain, spinal cord, and nerves. It is responsible for coordinating and controlling many body activities. It stimulates muscle contraction, creates an awareness of the environment, and plays a major role in emotions, memory, and reasoning.

Function Of Nervous Tissue

* Accept Impulses

* Transfer Impulses

* Senseatior