The Skeletal and muscular systems

The skeleton gives us shape, provides protection for internal organs and offers a framework for the attatchment of muscles. 

The bones act as a site for the production of blood cells and a store of minerals, in particular calcium. 

The average human has 206 bones, they are divided into two parts, axial skeleton and appendicular skeleton. 

Appendicular skeleton- The bones of the upper and lower limbs and their girdles that join to the axial skeleton, for example, the femur, humerous, scapula

Axial skeleton- This forms the long axis of the body and includes the bones of the skull, spine and rib cage. 

Ligament- A tough band of fiberous, slightly elastic, connective tissue that attaches one bone to another. It binds bones together to prevent dislocation. 

Tendon- A very strong connective tissue that attaches skeletal muscle to tissue.

Bone is made of collagen fibers filled with minerals(mainly calcium salts).

There are five types of bone in the body and they are classified according to their shape. The long bone consists of a shaft(diaphysis) and two ends(epiphysis).

The epiphysis is covered by articular cartilage(one of 3 types in our body) that acts as a cussion to absorb shock and prevent friction between bone. 

Children and young adults have a region between the diaphysis and each epiphysis called the growth plate which promotes longditudinal bone growth until physical maturity. 

Bones also contain cavities that are filled with bone marrow which generates new blood cells. 

Collagen - A fiborous protein with great strength.

Calcium - The mineral stored in the bone which keeps it hard and strong

Types of joint:

Fiberous-no movement-most stable-joints between the bones of the skull

Cartilaginous-little movement-stable-joints between the bodies of vertbrae

Synovial-free movement-least stable-joints between arms and legs 

Joints are the links between the bones of the skeleton. They enable movement but also allow stability in some areas of the body. 

Synovial fluid-a slippery fluid the consistency of egg whites-to reduce friction between cartilage

Joint capsule-a tough fiberous tissue which has two layers-helps to strengthen the joint while the synovial membrane lines and lubricates the joint.

Bursa-a small sac which contains synovial fluid to prevent rubbing of bones,ligaments,muscle or tendons.

Meniscus-a wedge of white fibrocartilage that improves stability and reduces wear and tear on joint surfaces.

Pad of fat-provides cusioning between the fibrous capsule and a bone or muscle