Types of Connective Tissue
Connective Tissues are classified into three types. They are:
1. Connective Tissue Proper
2. Supportive Tissue
3. Fluid Connective Tissue
A) Connective Tissue Proper: It is classified into two main types
i) Embryonic Connective Tissue
ii) Mature Coneective Tissue
i) Embryonic Connective Tissue: It is primarily in embryo and feotus. It includes: Mesenchyme, Mucous Connective Tissue
Mesenchyme: Derived from irregular mesenchymal cells.
All other connective tissues are derived from mesenchyme.
Ground substance is semifluid with reticular fibres .
Mucous Connective Tissue: Ground substance contain fibroblast cells, collagin fibre.
Mainly found in the umblical cord, where it is referred to as Whortan’s Jelly.
ii) Mature Connective Tisue:
(Write an account of meture connective tissue proper- 8marks)
It is present in the newborn and in the adult.
It is classified int two types: a) Loose connective tissue. b) Dense cnnective tissue.
a) Loose connective tissue:
1. In this tissue fibres are losly interrelated.
2. It is not very resistant to stress .
3. It is of three types. They are: Areolar tissue, Adipose tissue, Reticular connective tissue.
Areolar tissue: It contais all the three types of fibres- collagen fibres, Reticular fibres, and elastic fibres.
It contains several kinds of cells like – flibroblasts, mast cells, macrophages, plasma cells,Adipocytes and leuco cytes.
It combined with adipose tissue and form the subcutaneous layer.
The subcutaneous layer binds skin to underlying tissues.
Adipose tissue: It is fat storing tissue.
• It contributes to thermal insulation to the body.
• It forms the blubber of marine animals like whales and sea cows.
• It acts as shock absorber, in the soles and palms
• Subcutaneous adipose tissue is responsible for the body contour.
• It also occurs in yellow bone marrow.
• Cells in this tissues are adipocytes.
This adipose tissue is of two types. They are:
Brown fat( brown adipose tissue)
• In foetus and infant.
• The cells contain numerous lipid droplets.
• It has rich blod supply and numerous mitochondria
• It generates considerable heat and maintains body temparature in the new born.
White fat( white fat(whiteadipose tissue)
• Predominant in adults.
• The cells have a single large lipid droplet.
• Cytoplasm and nucleus are peripheral.
Reticular Connective Tissue:
• It consists of fine interlating reticular fibres and specialized fibroblasts(Reticular Cells)
• It forms the supporting frame work of haemopoietic organs and lymphoid organs( bone marrow, spleen, lymp nodes and liver and verticular lamina of basement membrane).
b) Dense Connective Tissue:
• It contains numerous, denser fibres but fewer cells.
• It is of three kinds:
Dense regular connective tissue: It has bundles of collagen fibres.
E.g. : Tendons( cnnect muscles to bones), Ligaments( connect bones to other bones.)
Dense Irregular Connective tissue: Bundles of collagen fibres are irregularly arranged.
E.g: It occurs in periosteum, pericardium, heart valves, joint capsules and in deeper region of dermis of skin.
Elastic connective tissue: Elastic fibres are predominant .
E.g.: It occurs in the walls of elastic arteries, vocal cords, trachea, bronchi.