Bones, Muscles, and Skin

What are the two main jobs of the skeletal system?

• support and protect the body
• digest food and carry messages for the body
• get rid of wastes and defend the body from disease
• sense changes in the environment and carry food through the body

Which activity does not use muscles?

• digesting an apple
• remembering a name
• jumping rope
• breathing air

What organ has these jobs: cools the body, keeps germs out, and senses temperature?

• skin
• eye
• blood
• brain

Ella waves good-bye from the bus. What body system pulls on bones to let Ella wave her arm?

• muscular system
• nervous system
• digestive system
• circulatory system

Nick is making a model to show how human skin covers the body. What material would work best?

• a sheet of rubber
• a sheet of paper
• a sheet of metal
• a sheet of wood

How does sweat on the skin help the body?

• Sweat stops sunburn.
• Sweat cools the body.
• Sweat feeds the skin.
• Sweat heals cuts.

Which organs do the ribs protect?

• stomach and lungs
• intestines and heart
• lungs and intestines
• heart and lungs

What helps skin feel heat and pressure?

• muscle cells
• blood cells
• nerve cells
• bone cells

Where do good bacteria grow to help keep people healthy?

• in the brain
• in the blood
• on the skin
• on the bones

The number of bones in the adult human body is___.

• fewer than 50
• about 500
• about 200
• about 100