CCLS 13-6: What Is the Muscular System?

Without muscles, the bones of the skeletal system could not move the body.

• True

• False

Muscles are attached to bones by ________________, which make movement possible.

• joints

• cartilage

• tendons

• tissue

Muscles only move bones when the muscles contract (or shorten). For this reason, muscles can only pull bones. They cannot push bones.

• True

• False

Muscles that straighten, or extend, your knee joint are called _______________.

• Flexors

• Extensors

Muscles that bend your knee joint are called _______________.

• Flexors

• Extensors

Muscles that bend and straighten the arm are called _____________ and ________________.

• deltoid, trapezius

• abdominal, pectoralis

• biceps, triceps

• sartorius, rectus

Triceps are _________________.

• flexors

• extensors

Biceps are _________________.

• flexors

• extensors

What are the benefits of regular exercise?

• the muscles in your body will be stronger and more flexible

• exercise will build your endurance, or allow your muscles to withstand more activity

• exercise will improve the condition of your heart

• all of the above

Running, bicycling, swimming, and playing basketball and soccer are examples of ________________ activity.

• anaerobic

• aerobic

• tiring

• none of the above