Atherosclerosis Quiz

What happens first when a sarcomere contracts?

• Nerve impulse reaches muscle

• ATP is released

• Myosin heads attach to actin

• Sarcomere shortens

What causes myosin protein heads to attach to actin filament?

• ATP

• Calcium ions

• Nerve impulse

• Sarcoplasmic reticulum

What is the effect of the sarcomere shortening?

• Decreases the size of the overall muscle

• Increases the size of the overall muscle

• Has no effect on muscle size

• Causes muscle relaxation

Which of the following is true about the M line?

• It is where actin molecules are bound.

• It is involved in muscle contraction regulation.

• It is the attachment site for myosin filaments.

• It stores energy in the form of ATP.

Which of the following is a component of actin filaments?

• M line

• Z line

• Tropomyosin

• Cross-bridge

What happens when a myosin head binds to an actin filament?

• A cross-bridge is formed.

• The M line is created.

• The Z line is extended.

• ADP is converted to ATP.

What is the primary function of the Z line in the sarcomere?

• To bind actin molecules.

• To attach thick filaments.

• To regulate muscle contraction.

• To store energy in the form of ADP.

Which component of the skeletal muscle contains actin and myosin?

• Sarcolemma

• Myofibril

• Blood vessels

• Fascia

Which part of the muscle fiber is responsible for its striated appearance?

• Sarcoplasm

• Sarcomere

• Myofibril

• Sarcolemma

What is the function of the fascia in muscle structure?

• It stores calcium ions.

• It provides structural support and protection.

• It generates energy.

• It transports oxygen.