Bones

BONES

The human skeleton is made up of 206 bones.

Bones are hollow in the middle and contain a substance called marrow

Light and strong

Felxible: living bone tissues which contain cells and collagen

Hard: Non-living part made of calcium phosphate.

Broken bones are repaired by the cells producing collagan fibres. 

Bones are strengthened by excercise.

Where 2 bones meet is called a joint

Red and hite blood cells are made inside the bone

Joints which allow movement are called synovial joints.

i.e. hinge and ball and socket. Movement at these joints could cause friction but a synovial joint is built to cut down friction.

This is done using CARTILAGE---- a tough, smooth substance on the surface ends of the bones. This acts as a shock absorber and stops the two bones rubbing.

SYNOVIAL MEMBRANE---- encloses synovial fluid & lubricates the joint. (stops friction!!!)

TENDONS--- Connect the muscle to bone.

LIGAMENTS--- strong, flexible fibres which hold bones together.

Joints

Pivot joints: 

NECK

Hinge:

patella

ankle bone

humerus/ ulna+radius

ball and socket:

scapula

Fixed:

skull

Fixed:

skull