Skeletal system of the man

Skeletal system consists of

Chemical composition of bones

• Water 50%

• Inorganic component 21.85% for hardness and rigidity

Calcium phosphate, calcium carbonate,magnesium, fluorine, sulphur

• organic component 28.5% for strength and flexibility

collagen Type 1 glycosaminoglycans, proteoglycans, glycoproteins

chemical composition varies with age and diet,organic matter becomes less inorganic salts become more it makes bones less flexible and more brittle

Bone loss results from inactivity, immobility,loss of normal stress on bones

Nutrition - Calcium, phosphorus

bones need Vitamins like D, A ,C

Locomotor apparatus

•Skeleton – forms a rigid supporting framework

•Joints - unite bones of the skeleton

•Ligaments and soft tissue connections -contribute to stability of joint

•Muscles -move joints

•Tendons-connect muscle to bone

•Nerves- innervate muscles

Types of bones

•Long bones

•Spongy bones

•Flat bones

•Irregular bones

•Pneumatic bones

Human skeleton consists of two main divisions-Axial skeleton and Appendicular skeleton

Axial skeleton-

longitudinal axis of the body . the skull, vertebral column, ribs and sternum

Appendicular skeleton-

upper extrimity-compromises the shoulder girdle,arm,forearm,wrist and hand.Two bones,the clavicle and scapula,form the shoulder girdle.

Lower extremity-The hip,thigh,leg,ankle and foot bones constitute the lower extremity.

Functions of bones

•Weight bearing

•Support

•Protection

•Locomption (act as lever system for muscles)

•Marrow forms blood cells

•Storehouse of calcium and phosphorous and their homeostasis

MedFaculty