scibone

Describe what happens to muscles when you bend the arm.

• The biceps muscle relaxes while the triceps muscle contracts.
• Both the biceps and triceps muscles contract simultaneously.
• The arm bones shrink in size.
• The biceps muscle contracts while the triceps muscle relaxes.

To straighten your arms, the triceps need to_______

and the biceps need to__________.

• contract; contract
• relax; contract
• relax; stretch
• contract; relax

To straighten your leg, the quadriceps need to______________.

hamstrings need to______________.

• bend, extend
• relax, tighten
• stretch, contract
• contract, relax

When you bend your leg, the quadriceps__________and

the hamstrings__________

• relax, contract

• flex, extend
• relax, tighten
• stretch, contract

The backbone, skull and ribcage support and.......................the organs in our body.

• protect
• cover
• hide
• shield

hard parts inside the body that form the skeleton.

• Bones
• Tendons
• Organs
• Muscles

Which bone protects organs such as the heart and lungs?

• femur
• radius
• scapula
• rib cage

Animal that do not have backbone are know as_________.

• Spineless
• Invertebrates
• Backless
• Vertebrates

Muscles relax and..........................to move the bones in our body.

• contract
• stretch
• expand
• shrink

we can move our legs with the help of..............................

• muscles

• contract

• skeleton

• move