Locomotion And Movement

Classi�cation of Bones

Structure of a Bone

Skeletal System - Functions Bones

Based on Location Based on Shape

Bone, cartilage, ligament and tendon form the Skeletal System.

• Provides shape and framework• Helps in movement and locomotion• Protects delicate organs, like rib cage protects heart and lungs

• Axial Skeleton: skull, rib cage, vertebral column• Appendicular Skeleton: upper and lower limbs, shoulder, pelvic girdle

Types of Cartilage

• Hyaline: helps surfaces slide over one another, found in respiratory system• Fibro: provides support and strength, found in healing tissue during bone repair• Elastic: maintains shape, found in middle ear

Cartilage• Made up of collagen and elastin fibres• Cartilage contains no blood supply• Chondroblasts: Cells that form cartilage• Chondrocytes: Mature cells of the cartilage• Chondrocytes lie in lacunae in the matrix• Perichondrium: Outer layer of cartilage

Axial Skeleton Appendicular Skeleton

• Each bone tissue is made up of two types of osseous tissue:

compact and spongy

• Compact bone: hard, compact, found

towards the outside of the bone

• Spongy bone: soft, found towards the

centre

• Periosteum: connective tissue found on

the outside of the bone, attaches

muscles and joints

• Endosteum: connective tissue, line the

marrow cavity

• Diaphysis: shaft of a bone, contains

marrow

• Epiphysis: swollen end of a bone

• Epiphyseal line demarcates diaphysis and epiphysis

• Blood cells are produced in marrow

• Osteoblasts form bone matrix and osteocytes are the mature cells of bones

• Osteoclasts: special gigantic cells, help to maintain, repair, remodel bones

• Matrix of a bone made up of organic part and inorganic part (hydroxyapatite)

• Long bones: long, slender, eg. humerus, femur• Short bones: smaller in size, eg. carpals, tarsals• Flat bones: thin and flat but all are not completely flat, eg. scapula, sternum• Irregular bones: no specific shape, eg. vertebrae

• We have 206 bones which forms more than 200 joints in our body• A new born child has 305 bones

Skeletal System

Cartilage

Epiphyseal line

Medullary cavity

Nutrient vessel

Bone marrow

Spongy bone

Diaphysis

Endosteum

Periosteum

Compact bone

Epiphysis