Bones and Joints
Table of Contents

The skeleton is the framework around which the body is constructed and on which all the tissues of the body depend for support. So that we can move, the skeleton is jointed at several places. Muscles attached to the bones work to make them move.


What follows is a list of the major bones of the body that comprise the skeleton:

The head is made of a number of fused plates in the adult, unfused in the newborn, making up the skull. The jawbone is also known as the mandible.

Upper limb:
The shoulder girdle comprises the collar bone (clavicle) and shoulderblade (scapula), attached at the shoulder joint to the upper arm bone (humerus). The clavicle holds the upper limb away from the chest. The bones of the lower arm are termed the ulna and radius. The hand bones are referred to sometimes as carpals.

The ribcage is constructed of 12 curved ribs attached to the spine at the back, 10 of which are attached to the sternum (breastbone) by cartilage.

The backbone, or spine, is formed by a column of small bones called vertebrae. The top 7 are called cervical vertebrae, the next 12 thoracic, then 5 lumbar vertebrae, followed by the sacrum and coccyx.

This basin-shaped structure is attached to the lower spine.

Lower limbs:
The thigh bone (femur) joins the pelvis at the hip joint. The leg is jointed at the knee, which is protected at the front by the kneecap (patella) and at the ankle. They are joined by the shin bone (tibia) and fibula to the foot (tarsal).

Wherever on bone meets another, there is a joint. There are two main joints—movable and immovable. Movable joints allow movement between adjacent bones and are of three types:

Gliding joints:
These are shaped to allow only slight gliding or rocking movements. Examples are the joints between the vertebrae, hands and feet.

Ball and socket joints:
The round head of one bone fits into the cup-shaped cavity of another. The swilling action allows movement in all directions. Examples are the shoulder and hip.

Hinge joints:
The surfaces of the bone ends are contoured together to allow bending (flexion) and straightening (extension) in only one plane. Examples are the elbow and knee.


Muscles cause various parts of the body to move by their relaxation and contraction. There are two types:

Voluntary muscles:
The muscles are controlled at will and are attached to the bones by bands of strong, fibrous tissue (tendons). They operate in groups, so that as one contracts the other relaxes.

Involuntary muscles:
These operate internal organs and work continuously. For example the intercostal muscles between the ribs that control breathing and the cardiac muscles that control the beating of the heart.

(A furthur look at bone injuries can be found in '+hlr frac' which includes joint material)

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