Science - Skeleton and Muscles

Skeleton and Muscles

An Endoskeleton is found inside the body as in animals and humans whereas an Extoskeleton is found on the outside of the body and is found in insects and crustceans ( animals such as ...lobster, crab, crayfish, shrimp, krill, woodlice and barnacles).

A skeleton has three main functions they are:

1. PROTECTION - The skeleton protects important INTERNAL ORGANS. The skull protects the brain and the pelvis protects the reproductive organs as well as that the ribs protect the heart and lungs.

2. SUPPORT - This is the main function of the skeleton - to SUPPORT OUR BODIES. Without a skeleton we would be very floppy.

3. MOVEMENT - The skeleton helps our bodie to move by a system of JOINTS and by providing a base for MUSCLES TO ATTACH TO.

Joints

1. Hinge Joints - These allow movement in 1 plane only ( 180 degrees), they are found in the elbow and knee. Like a door hinnge, this type of joint PREVENTS ROTATIONAL movement.

2. Ball and socket joints - These allow rotatory movement, they are found in the shoulder and hip. The ball shaped head of the thigh/arm bone allows a WIDE RANGE OF ROTATION ( 360 Degrees) and thus  different positions for the leg or arm.

3. Semi-moveable Joint - These allow a little movement, they are found in the joints between the vertebrae (spine) in the back bone.

4. Fixed joint - These allow no movement at all they are found in the skull bones.

5. A Synovial joint - Contains fluid to lubricate joint

A Synovial Joint has 4 main parts to it they are:

1. The capsule - Holds the bones of the…