Muscle Physiology Questions

The outermost layer of connective tissue surrounding a skeletal muscle is called the

• epimysium.

• perimysium.

• endomysium.

• sarcomysium.

Myofibrils are composed primarily of

• actin and myosin.

• ATP and ADP.

• troponin.

• tropomyosin.

Neurotransmitters are stored in vesicles within

• myofibrils.

• motor units.

• the motor end plate.

• motor neuron endings.

ADP molecules on the surface of actin serve as active sites for the formation of cross-bridges with molecules of

• ATP.

• myosin.

• troponin.

• tropomyosin.

The enzyme cholinesterase causes acetylcholine to

• bond to actin.

• be secreted from the motor end plate.

• decompose.

• form cross-bridges.

Creatine phosphate serves to

• cause the decomposition of ATP.

• cause the decomposition of ADP.

• supply energy for the synthesis of ATP.

• supply energy for the change of ATP to ADP.

The amount of oxygen needed to support the conversion of lactic acid to glycogen is called the

• refractory quantity

• oxygen debt

• anaerobic concentration

• aerobic conversion

A muscle cramp is most likely due to a lack of

• actin

• myosin

• ATP

• ADP

The all-or-none response means that

• all of the muscles in a region contract together.

• all of the muscle fibers within a muscle contract together.

• when a muscle fiber contracts, it contracts completely.

• when a muscle fiber contracts, all of its ATP is changed to ADP.

An example of a partial but sustained contraction would be

• muscle tone.

• tetany.

• twitch.

• all of the above