Muscular System Quiz

What is the function of the neuromuscular junction?

• To release acetylcholine into the synaptic cleft

• To open Ca2+ channels

• To bind to troponin

• To release stored calcium

What happens when Ca2+ binds to troponin?

• Acetylcholine is released

• Na+ channels open

• Tropomyosin moves

• Myosin heads bind to actin

What is the role of ATP in muscle contractions?

• To release acetylcholine

• To break down troponin

• To supply energy

• To open Ca2+ channels

What is a muscle twitch?

• A sustained contraction

• A single contraction of a muscle fiber

• The time during which the muscle relaxes

• The time between the application of a stimulus and the beginning of contraction

What is the process of individual muscles contracting more forcefully called?

• Summation

• Tetanus

• Recruitment

• Multiple-wave summation

Which type of muscle fiber contracts slowly and is used by long distance runners?

• Slow twitch fibers

• Fast twitch fibers

• A blend of both fibers

• None of the above

Where does the energy for muscle contractions come from?

• Aerobic production of ATP

• Anaerobic production of ATP

• Conversion of creatine phosphate to ATP

• All of the above

Tags

NGSS.HS-LS1-7

NGSS.HS-LS2-3

What causes muscle fatigue?

• Acidosis and ATP depletion

• Oxidative stress

• Local inflammatory reactions

• All of the above

Tags

NGSS.HS-LS1-7

What type of contraction occurs when muscle tension increases as the muscle shortens?

• Isometric contraction

• Concentric contraction

• Eccentric contraction

• None of the above

What is responsible for keeping the back and legs straight?

• Muscle tone

• Smooth muscle

• Cardiac muscle

• None of the above