Exercise 13- Contraction of Skeletal Muscle (A. and B.)

Explain why muscles are stiff (contracted) when rigor mortis occurs

After death ATP production stops. W/O ATP cross bridges cross bridges cannot detach from actin binding sites so muscles remain stiff.

T/F Glycerinated skeletal muscle fibers need calcium in order to contract.

False

Weight Lifter uses:

Fast glyclotic

Which type of muscle would fatigue faster, one that has many blood vessels, or one that has fewer blood vessels? Explain

Fewer because it has lower Oxygen capacity. Oxygen causes more production of ATP by glycolysis. Lactic acid produced contributes to fatigue.

Large muscles, such as the muscles of the leg have more muscle fibers than small muscles, such as the muscles of the finger. Explain why the muscles of the finger cannot develop as much force as the muscles of the leg.

Finger muscle fibers have fewer myofibrils, therefore fewer cross bridges than your leg muscles. Force development is dependent on the # of cross bridges attached to actin

Smiling is an example of:

Fused Tetanus

Marathon Runner uses

Slow oxidative

T/F - ATP causes the detachment of myosin from actin

True

T/F Glycerinated skeletal muscle fibers need ATP in order to contract.

True

Muscle Spasm is an example of :

Unfused tetanus

Fast oxidative-glycolytic

a.) Is pink in color b.) Has glycogen stores c.) Generates ATP by aerobic respiration or glycolysis

Fast Glycolytic Muscle Fibers

a.) Largest in diameter b.) fastest contraction velocity c.) recruited last d.) has glycogen stores e.) myoglobin content is low

Slow Oxidative Muscle Fibers....

a.) smallest in diameter b.) has many capillaries c.) red in color d.) generates ATP by aerobic respiration e.)has the slowest myosin ATPhase f.) Recruited first

100- Meter Dash runner uses

fast oxidative glyclotic fibers

Fast oxidative- glcolytic and Fast Glycolytic both have:

glycogen stores

Cardiac Fibrillation is an example of a:

twitch

Facial Muscle Tic is an example of:

twitch