5 important functions of the skin
- Forms a barrier against disease
- Helps body maintain steady temperature
- Helps eliminate waste through perspiration
- Contains nerves that gather information about environment
- Skin cells produce vitamin D to help body absorb calcium.
Name the 2 layers of the skin
- Top layer - epidermis. Thinner than dermis. Doesn not have nerves or blood vessels
- Bottom layer - dermis. Located above a layer of fat that pads the organs. Contains nerves, blood vessels, sweat glands, hair and oil glands.
Break in a bone. Swelling can occur.
Ligaments are stretched too far and tear in places. Can cause swelling. Sprained ankle is most common joint injury.
3 Main Skeletal Injuries
When a bone comes out of its joint
What is the largest organ in the human body?
How do skeletal muscles work?
In pairs. When one muscle contracts and shortens, the other muscle in the pair expands and lengthens to its original length.
What is compact bone?
It is beneath the membrane. It is hard but not solid. Canals carry blood vessels and nerves from the bone's surface to the living cells within the bone.
What is spongy bone?
Found just inside compact bone, spongy bone has many small spaces within it. It is lightweight but strong, and also found at the ends of the bones.
Why do xrays show bones and not tissues or muscles?
Bone absorbs xrays, other body tissues do not
How to prevent skeletal injuries
Warming up before exercise, wearing protective equipment & exeecising in safe places
Advantages of MRI over xray?
Can see tissue and bones and does not cause harm to the body.
Advantage of xray?
Sees only bone and low cost.
What gives skin its color?
Melanin. Produced in the epidermis. The sun makes the skin produce more melanin.