Chapter 6:The Skeletal System
-
To support the body
-
To allow movement
-
To protect delicate organs e.g. brain
-
The skeletal system is made up of bones and muscles along with ligaments, tendons and joints
-
An adult human has a total of 206 bones
Functions of the Skeletal System:
The skeleton as a protector:
-
The skull protects the brain
-
The ribs protect the heart, lungs and liver
-
The backbone protects the spinal cord
-
Bone is composed of two parts. A hard mineral part containing calcium (inorganic) and a softer more flexible part containing protein (inorganic)
Joints:
-
A joint is where one bone meets another one
-
There are two types of joints both fused and synovial joints
-
Fused joints are joints which does not allow movement (e.g. The skull)
-
Synovial joints are joints which allow bones to move
-
There are two types of synovial joint, hinge and ball and socket joints​
-
Ball and socket joints allow movement in several directions (e.g. shoulder and hip joints and hinge joints allow movement in one plane only (e.g. elbow and knee joints).
A diagram of a knee joint
-
Ligaments joins one bone to another
-
However tendons connect a bone to a muscle
-
Synovial fluid in the joint above is used to cushion and lubricate the joint
-
Cartilage is used to prevent bones from knocking against one another
Joint Parts and Functions
Muscles:
-
Muscles are required to bring about movement
-
Muscles work in antagonistic pairs. This means that as one muscle relaxes the other one contracts allowing for movement of bones
-
An example of an antagonistic pair ofmuscles are the biceps and the triceps. As the tricep relaxes the bicep contracts lifting the arm
