● `color{brown}("Connective tissues")` are most `color{violet}("abundant")` and widely distributed in the body of `color{violet}("complex animals.")`

● They are named `color{violet}("connective tissues")` because of their special function of linking and supporting other `color{violet}("tissues/organs")` of the `color{violet}("body.")`

● They range from `color{brown}("soft")` connective tissues to `color{brown}("specialised")` types, which include `color{violet}("cartilage, bone, adipose, and blood.")`

● In all `color{violet}("connective tissues except blood,")` the cells `color{violet}("secrete fibres")` of structural proteins called `color{brown}("collagen or elastin.")`

● The `color{violet}("fibres provide strength, elasticity")` and `color{violet}("flexibility")` to the `color{violet}("tissue.")`

● These `color{violet}("cells")` also secrete modified `color{violet}("polysaccharides,")` which accumulate between `color{violet}("cells")` and `color{violet}("fibres")` and act as `color{violet}("matrix (ground substance).")`

● `color{violet}("Connective tissues")` are classified into three types:

(i) `color{brown}("Loose connective tissue")`
(ii) `color{brown}("Dense connective tissue")`
(iii) `color{brown}("Specialised connective tissue.")`

● `color{brown}("Loose connective tissue")` has `color{violet}("cells and fibres")` loosely arranged in a semi-fluid ground substance.

`star` `color{green}("Areolar Tissue:")`
● `color{brown}("Areolar tissue")` present beneath the skin.

● Often it serves as a support framework for `color{violet}("epithelium.")`

● It contains `color{violet}("fibroblasts")` (cells that produce and secrete fibres), `color{violet}("macrophages")` and mast cells.

`star` `color{green}("Adipose Tissue:")`
● `color{brown}("Adipose tissue")` is another type of `color{violet}("loose connective tissue")` located mainly beneath the skin.

● The cells of this `color{violet}("tissue")` are `color{violet}("specialised")` to store fats.

● The `color{violet}("excess of nutrients")` which are not used immediately are converted into fats and are stored in this `color{violet}("tissue.")`

● `color{violet}("Fibres and fibroblasts")` are compactly packed in the `color{brown}("dense connective tissues.")`

● Orientation of `color{violet}("fibres")` show a regular or irregular pattern and are called `color{brown}("dense regular")` and `color{brown}("dense irregular tissues.")`

● In the `color{brown}("dense regular")` connective tissues, the collagen `color{violet}("fibres")` are present in rows between many parallel `color{violet}("bundles of fibres.")`

● `color{brown}("Tendons")`, which attach skeletal `color{violet}("muscles")` to `color{violet}("bones")` and `color{brown}("ligaments")` which attach `color{violet}("one bone")` to another are examples of this `color{violet}("tissue.")`

● `color{brown}("Dense irregular")` connective `color{violet}("tissue")` has `color{violet}("fibroblasts")` and many `color{violet}("fibres")` (mostly collagen) that are oriented differently.

● This `color{violet}("tissue")` is present in the skin.

● `color{violet}("Cartilage, bones and blood")` are various types of `color{brown}("specialized connective tissues")`.

`star` `color{green}("Cartilage:")`

● The intercellular material of `color{brown}("cartilage")` is `color{violet}("solid")` and `color{violet}("pliable")` and resists compression.

● Cells of this `color{violet}("tissue")` (chondrocytes) are enclosed in `color{violet}("small cavities")` within the matrix secreted by them.

● Most of the `color{violet}("cartilages")` in vertebrate embryos are replaced by `color{violet}("bones in adults.")`

● `color{violet}("Cartilage")` is present in the tip of `color{violet}("nose, outer ear joints")`, between adjacent `color{violet}("bones")` of the vertebral column, limbs and hands in adults.

`star` `color{green}("Bones:")`

● `color{brown}("Bones")` have a `color{violet}("hard and non-pliable")` ground substance rich in calcium salts and collagen fibres which give bone its strength.

● It is the `color{violet}("main tissue")` that provides `color{violet}("structural frame")` to the body.

● `color{violet}("Bones")` support and protect softer `color{violet}("tissues and organs.")`

● The `color{violet}("bone cells")` (osteocytes) are present in the spaces called `color{violet}("lacunae")`.

● `color{violet}("Limb bones,")` such as the `color{violet}("long bones")` of the legs, serve weight-bearing functions.

● They also interact with skeletal muscles attached to them to bring about movements.

● The `color{violet}("bone marrow")` in some bones is the site of production of `color{violet}("blood cells.")`

`star` `color{green}("Blood:")`

● `color{brown}("Blood")` is a fluid connective `color{violet}("tissue")` containing `color{violet}("plasma, red blood cells (RBC), white blood cells (WBC) and platelets")`.

● It is the main `color{violet}("circulating fluid")` that helps in the transport of various substances.