Muscle Structure and Function Quiz

What is the basic functional unit of a muscle called?

• Sarcomere

• Myofibril

• Muscle fiber

• Fascicle

Which type of muscle tissue is under voluntary control?

• Cardiac muscle

• Smooth muscle

• Skeletal muscle

• Epithelial muscle

Explain how the sliding filament theory describes muscle contraction.

• Actin and myosin filaments slide past each other, shortening the sarcomere.

• Myosin filaments dissolve, allowing actin to contract.

• Actin filaments break down, causing muscle contraction.

• Myosin filaments elongate, pushing actin filaments apart.

Identify the protein that binds calcium ions to initiate muscle contraction.

• Tropomyosin

• Troponin

• Myosin

• Actin

Describe the role of ATP in muscle contraction.

• ATP provides energy for the detachment of myosin heads from actin.

• ATP binds to actin, causing it to contract.

• ATP is stored in the sarcoplasmic reticulum for future use.

• ATP is converted into ADP, which powers the contraction.

Which type of muscle is voluntary?

• A. Skeletal

• B. Smooth

• C. Cardiac

• D. None of the above

What is the outermost layer that surrounds the entire muscle?

• A. Epimysium

• B. Perimysium

• C. Endomysium

• D. Myofibrils

What is the contractile unit of a muscle fiber?

• A. Sarcolemma

• B. Sarcoplasm

• C. Sarcomere

• D. T tubule

What is the neurotransmitter that crosses the gap between the neuron and motor end plate?

• A. Acetylcholine

• B. Cholinesterase

• C. Serotonin

• D. Dopamine

What is the theory of how muscle contracts called?

• A. Sliding Filament Theory

• B. Sarcomere Theory

• C. Myofibril Theory

• D. Actin-Myosin Theory