The Marvelous World of Muscles

Which type of muscle is involuntary and found only in the heart?

• Skeletal Muscle

• Cardiac Muscle

• Smooth Muscle

Skeletal muscles are under ______ control and have a striated appearance.

• involuntary

• voluntary

• automatic

Which of the following is a function of muscle tissue?

• Digestion

• Movement production

• Vision

• Respiration

The ______ is a bundle of muscle fibers.

• Myofibril

• Fascicle

• Sarcomere

• Z line

Which layer of connective tissue surrounds the entire muscle?

• Epimysium

• Perimysium

• Endomysium

• Myomysium

The _______ is the layer of connective tissue that surrounds bundles of muscle fibers (fascicles).

• Epimysium

• Perimysium

• Endomysium

The thick filaments in a sarcomere are primarily composed of ______.

• Actin

• Myosin

• Titin

• Z-line

What is the basic unit of muscle contraction?

• Myofibril

• Sarcomere

• Muscle fiber

• Actin

The thick filaments in a sarcomere are primarily composed of ______.

• Actin

• Myosin

• Titin

• Z-lines

Which of the following is the first step in the sliding filament model of muscle contraction?

• Myosin heads bind to actin, forming crossbridges

• Myosin heads split ATP and become reoriented and energized

• Myosin heads rotate toward the center of the sarcomere (power stroke)

• As myosin heads bind ATP, the crossbridges detach from actin