Muscular System

ability of muscle to shorten and produce tensions at its ends

• contractibility

• excitability

• elasticity

• extensibility

How many different types of muscle tissue are in the human body?

• 2

• 3

• 4

• 5

Look at the image of cardiac muscle. Which of the following best describes what you see?

• All the muscle fibers are shaped like eyes.

• The muscle fibers are branching and connected to each other.

• All the muscle fibers are oval and purple.

• All the muscle fibers are running parallel to each other.

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

• Actin myofilaments

• Myosin myofilaments

• Troponin molecules

• Tropomyosin filaments

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

• Actin myofilaments

• Z disks

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

• Depolarization

• Repolarization

• Resting membrane potential

• Action potential

Tags

NGSS.HS-PS3-5