9. Muscle Tissue

What layer of connective tissue surrounds and separates muscle fibers?

A fascicle is a bundle of:

The plasma membrane of a muscle fiber is called the ____________ and it wraps bundles of ____________. 

True or False: if false, chose the answer that corrects the statement.

The smallest contractile unit of a muscle is the muscle cell.

The connective tissue covering that encloses the sarcolemma of an individual muscle fiber is called the:

a. Epimysium

b. Perimysium

c. Endomysium

d. Periosteum

A fascicle is a:

a. Muscle

b. Bundle of muscle fibers enclosed by a connective tissue sheath

c. Bundle of myofibrils

d. Group of myofilaments

Thick and thin myofilaments have different compositions. For each descriptive phrase, indicate whether the filament is, a. thick or b. thin. 

_____ (1) contains actin 

_____ (2) contains ATPases 

_____ (3) attaches to the Z disc 

_____ (4) contains myosin 

_____ (5) contains troponin 

_____ (6) does not lie in the I band

The function of the T tubules in muscle contraction is to:

a. Make and store glycogen

b. Release Ca²⁺ into the cell interior and then pick it up again

c. Transmit the action potential deep into the muscle cells

d. Form proteins

True or false: Most muscles contain a predominance of one skeletal muscle fiber type. Explain the reasoning behind your choice.

The primary action of the biceps brachii muscle of the anterior arm is to flex the forearm at the elbow. However, when this muscle is inflamed, pain is felt in the shoulder. Explain this finding.

Which of the following types of muscle fibers have low myosin ATPase activity and are classified as slow-twitch?

a. Type I fibers

b. Type IIa fibers

c. Type IIx fibers

d. Type III fibers