Muscular System Quiz

What is the basic structural and functional unit of a skeletal muscle?

• Myosin filament

• Sarcomere

• Actin filament

• Z disk

What forms a network of protein fibers and separates one sarcomere from the next?

• Actin myofilaments

• Z disks

• Troponin molecules

• Tropomyosin filaments

What gives skeletal muscle its striated appearance and ability to contract?

• Actin myofilaments

• Myosin myofilaments

• Troponin molecules

• Tropomyosin filaments

What are the light-staining bands in a sarcomere called?

• I bands

• A bands

• Z disks

• Myosin myofilaments

What are the dark-staining bands in a sarcomere called?

• I bands

• A bands

• Z disks

• Actin myofilaments

What component of actin myofilaments blocks the myosin myofilament binding sites?

• Actin

• Troponin

• Tropomyosin

• Myosin heads

What are myosin myofilaments also known as?

• Actin myofilaments

• Z disks

• Troponin molecules

• Thick myofilaments

What is the electrical charge difference across the cell membrane of an unstimulated cell called?

• Resting membrane potential

• Action potential

• Depolarization

• Repolarization

What triggers the opening of gated Na+ channels in a skeletal muscle fiber?

• Depolarization

• Repolarization

• Resting membrane potential

• Action potential

What is the neurotransmitter that stimulates skeletal muscles?

• Acetylcholine

• Adrenaline

• Dopamine

• Serotonin