The Muscular System

1.) Which of the following is NOT a function of muscle tissue?

• Produce movement
• Maintain body temperature
• Guard entrances and exits
• Support soft tissues
• All of these are functions of muscle tissue

2.) Connective tissue that surrounds each muscle fiber or cell is called:

• Perimysium
• Endomysium
• Fascia
• Fasciculi
• Microfibrils

3.) Muscle myofibrils:

• Contain actin and myosin myofilaments
• Extend from one end of the muscle fiber to the other
• Contain sarcomeres joined end to end
• All of the above
• None of the above

4.) The basic structural and contractile unit of a muscle cell/fiber is:

• The fasciculus
• The muscle fiber
• The myofibril
• The sarcomere
• The actin myofilament

5.) Actin myofilaments

• Resemble bundles of tiny golf clubs
• Are attached to Z lines
• Form from the myosin filaments
• Form the epimysium
• All of the above

6.) Each sarcomere

• Extends from one Z line to the next
• Has light colored H zone in the center
• Contains I bands and an A band
• Contains overlapping actin and myosin myofilaments
• All of the above

7.) Tendons are bundles of collagen fibers at the end of a skeletal muscle that:

• Attach bone to bone
• Allow blood vessels and nerves to innervate muscle tissue
• Attach muscle to bone
• None of the above statements are correct

8.) Acetylcholine

• Is a neurotransmitter at the neuromuscular junction
• Is broken down by acetylcholinesterase
• Binds to receptors on the muscle cell membrane
• Causes as influx of sodium ions into the muscle cell
• All of the above

9.) A single motor neuron and all the skeletal muscle fibers it attaches to is called a:

• Neuromuscular junction
• Synaptic cleft
• Motor unit
• Synapse
• Presynaptic cleft

10.) In a neuromuscular junction

• Th presynaptic terminal contains vesicles filled with sodium ions.
• The presynaptic terminal contains receptor molecules for the neurotransmitter.
• The presynaptic terminal is separated from the postsynaptic terminal by the synaptic cleft.
• The neurotransmitter causes an action potential in the presynaptic terminal.
• All of the above