The skeletal system includes all of the bones and joints in the body. Each bone is a living organ that is made up of many cells, protein fibers and minerals. The skeleton acts as a support that allows the body to stay upright and protection for the soft tissues that make up the rest of the body. The skeletal system also provides attachment points for muscles to allow movements at the joints. New blood cells are produced by the red bone marrow inside of our bones. Bones act as the body’s warehouse (place to store) for calcium, iron, and energy in the form of fat. Finally, the skeleton grows throughout childhood and provides a framework for the rest of the body to grow along with it.

The skeletal system in an adult body is made up of 206 individual bones. These bones are arranged into two major divisions: the axial skeleton and the appendicular skeleton. The axial skeleton runs along the body’s midline axis and is made up of 80 bones. The appendicular skeleton is made up of 126 bones.

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Joints

If the skeleton consisted of only one solid bone, movement would be impossible. Nature has solved this problem by dividing the skeleton into many bones and creating joints where the bones intersect. Joints are strong connections that join the bones, teeth, and cartilage of the body to one another. Three types of joints are:

1. Hinge - these can be found in the elbow, knee and ankle. Hinge joints are like the hinges on a door, and allow you to move the elbow and knee in only one direction. They allow flexion and extension of a joint.

2. Ball and socket - these types of joint can be found at the shoulder and hip and allow movement in almost every direction. A ball and socket joint is made up of a round end of one bone that fits into a small cup-like area of another bone.

3. Pivot - this joint can be found in the neck between the top two vertebrae. It allows only rotational movement such as moving your head from side to side as if you were saying 'no'.

How Joints are Connected

There are 3 main types of connective tissues: ligaments, tendons and cartilage.

Cartilage is found at the end of bones where joints meet. It is a soft, spongy connective tissue that cushions the joint and prevents friction and wear and tear between the bone ends.

Muscles are attached to bone by tendons. Tendons are very strong, inelastic connective tissues that allow a muscle to pull on a bone to move it.

The bones at a joint are connected by ligaments. Ligaments are a type of connective tissue and are tough, fibrous and slightly elastic. They connect bone to bone and help keep the joint together. They stabilize the joints during movement and prevent dislocation by restricting actions outside the normal joint range. They also absorb shock because of their elasticity, which protects the joint.