Biology report 2nd semester week 1

Skeletal system
Functions:

• provides frame
• produces blood cells
• provides protection
• helps to breathe
• stores minerals
  

Bones:
Types:

1. Long Bones - larger than they are wide
2. Short Bones - equal sized in width & length
   
3. Flat Bones - thinner bones
4. Irregular Bones - like parts of a jigsaw puzzle
   

Bone Tissue:

1. Compact - dense, hard. outer layers of the other bones
2. Spongy - arranged in trabeculae

Surface Structures of Bones:

• not smooth
• have projections, bumps & depression

Bone Growth and Repair

• Ossification - formation of bone

Cells involved;

1. Osteoprogenitor celss - non specialized cells found in the periosteum, endosteum, cnetral canal
2. Osteoblasts - secretes a matrix of Ca
3. Osteocytes - mature bone cells
4. Osteoclasts - tears down bone material