• Connective tissue: They are supporting tissues of the body and also bind other tissues together, they contain large amount of inter cellular material or matrix as well as special cells

• They have several functions

• They give structural supports e.g. bones
• They connect other tissue together e.g. ligaments and tendons
• They function in protection e.g. adipose tissue
• They function in transport of respiratory gases and defense e.g. blood
• They are made up of cells e.g. fibroblast
• They are many types of connective tissues with widely different functions such as white fibrows, yellow elastic skeletal.

I. SKELETAL TISSUES

1. Cartilage

• It is solf and adapted to resist any strength on i. it is compressible and elastic. It also forms a frame work for attachment of muscles. It protects under lying tissues and forms a structural model for developing bones. It consists of a tough matrix of proteins called chrondin containing numerous active cells called chrondroplast. They are contain in spaces called lacunal whose cells form numerous young once called chondrocytes
• The magins of cartilage contain dead layers of cells with numerous fibrils called perichondrium. It is from here that many new chrondroplast are form: white fibrous, yellow elastic and hyaline
• They lack blood vessels but food oxygen reached them by diffusion.

They are3 main types of cartilage:

1. Hyaline cartilage

• It is elastic compressible and can resist any form of strength. They are located at the end of most joints called articular cartilage or at the end of ribs called costal cartilage
• It is also located in the respiratory system

2. Yellow or elastic cartilage

• It is more flexible than hyaline because it matrix is made up of more elastic fibres
• It is located in the external ear, epiglottis and larynx

3. White fibrous cartilage

• It is very tough with numerous closely parked cells that form collagen fibres
• It serves as a sock absorber to structures which are subjected to pressure
• It is located within the bones in the knee and between adjacent vertebrae

2. BONE

It is hard unbreakable and contains a tense matrix which contains organic materials which make up 30% of bones containing bone cell and collagen fibres.

1. Inorganic materials

It is made up of 70% and contains calcium and phosphate ions that give the bone its rigidity. There are 2 hormones that control the inorganic material in the bone which are calcitonin and parathorme. There are 2 main types of bones:

• Compact bone

• His matrix contains many layers called lamellae which are arranged in a concentric pattern. Each lamella surrounds a ting tube called haruesian canal which contains nerves blood vessels and lymph vessels
• Bone cells called osteoblast are distributed between the lamellae and help in the formation of new bones. The cytoplasm of each osteoblast contains organelles such as endoplasmic reticulum, mitochondria with Golgi bodies rich in RNA
• When the osteoplast are not active they are surrounded by lacunae and are called osteocytes. The osteocytes and osteoblast have layers of intercellular material which forms a cylinder shape unit called harvesian system

• Spongy bone or trabecular bone

• It contains numerous interconnected bones structures called the traberculae
• It contains less inorganic materials than compact bones
• The spaces between the traberculae are filled with marrow tissue which can either gives red marrow at the end of bone or yellow marrow within the straft.

II.  Function of bones

• They form a frame work
• They protect internal organs e.g. brain and heart
• They give shape to the body
• Help in movement of part or whole organism
• Help in support
• Contains bones marrows which provide white and red blood cells
• It’s used to determine the half shell lipe of an organ