Muscle Contraction Quiz

According to the sliding filament theory,

• actin filaments force the Z lines farther apart.

• actin filaments "walk" along the myosin filaments.

• myosin filaments "walk" along the actin filaments.

• none of the above

Fill in the blank(s): The actin and myosin filaments are organized into repeating units, known as

Compared to each other, actin filaments are thin and myosin filaments are thick.

• TRUE

• FALSE

Fill in the blank(s): The ____________________ junction is the area when a motor neuron meets a muscle fiber.

Inside the motor neuron, the signal is _______ in nature, crossing the junction, the signal is _______ in nature.

• electrical, chemical

• chemical, electrical

• electrical, electrical

• chemical, chemical

Fill in the blank(s): ____________________ filaments uses energy from ATP to pull the actin filaments closer.

The energy myosin needs to function comes from

Which is correct?

• When the sarcomere shortens, the Z discs move closer together.

• When the sarcomere shortens, the H zone becomes smaller.

• When the sarcomere shortens, the M line is unchanged.

• all of the above

Within a sarcomere, myosin filaments overlap the actin filaments.

• TRUE

• FALSE

During a muscle contraction, muscle fibers _____.

• shorten

• relax

• bind

• none of the above