Muscular System Test

Which type of muscle tissue is involuntary and found in the walls of hollow internal organs?

• Cardiac muscle

• Skeletal muscle

• Smooth muscle

• Striated muscle

Which of the following is the basic contractile unit of a muscle fiber?

• Myofibril

• Sarcomere

• Actin

• Myosin

Which ion is essential for muscle contraction?

• Sodium

• Potassium

• Calcium

• Chloride

What type of muscle is under voluntary control and has striations?

• Skeletal muscle

• Smooth muscle

• Cardiac muscle

• Striated muscle

Explain the role of ATP in muscle contraction and relaxation.

• ATP provides energy for the power stroke and detachment of myosin from actin.

• ATP stores calcium ions in the sarcoplasmic reticulum.

• ATP inhibits acetylcholine release.

• ATP forms the structure of the sarcomere.

Which protein blocks the myosin binding sites on actin in a relaxed muscle?

• Troponin

• Tropomyosin

• Myosin

• Actin

Which of the following is NOT a function of the muscular system?

• Movement

• Circulation of substances

• Hormone production

• Heat generation

Compare the structure of skeletal muscle tissue to cardiac muscle tissue.

• Both are striated, but only cardiac muscle has intercalated discs.

• Both are non-striated and voluntary.

• Skeletal muscle is involuntary, cardiac muscle is voluntary.

• Cardiac muscle has multinucleated cells, skeletal muscle does not.

Which step initiates the sliding filament process in muscle contraction?

• Release of calcium ions

• ATP binding to myosin

• Formation of cross-bridges

• Detachment of myosin from actin

Which protein forms the thick filaments in muscle tissue?

• Actin

• Myosin

• Troponin

• Tropomyosin