Muscular - lectures 2 & 3

True or False: Actin is the thin filament.

• True

• False

What band does not get smaller when the muscle contracts?

• A band

• H zone

• I band

• None of the above.

What is released from the sarcoplasmic reticulum after the action potential?

• O2

• Nitrogen

• Ca2+

• Phosphorus

During muscle contraction, the contractile proteins get shorter.

• True

• False

The release of this from the sarcoplasmic reticulum allows tropomyosin to uncover the myosin binding site.

• Myosin

• Troponin

• Calcium

• Titin

Calcium must bind to troponin for muscle contraction to occur.

• True

• False

The H zone shrinks during muscle contraction.

• True

• False

Without calcium there is no muscle contraction.

• True

• False

Type I fibers are ______ twitch fibers.

• fast

• intermediate

• slow

• all of the above

The I band only contains myosin filaments.

• True

• False