Free Muscles MCQs with Answers

1. Which type of muscle is striated but under involuntary control?

• A. Cardiac muscle
• B. Skeletal muscle
• C. Smooth muscle
• D. None of the three

Explanation: Cardiac muscle has the cross striations of skeletal muscle because it uses the same actin and myosin arrangement, but it contracts rhythmically on its own without conscious control and its fibres are branched and joined by intercalated discs. Skeletal muscle is striated and voluntary, and smooth muscle is involuntary but has no striations, so cardiac muscle is the only combination of both features.

2. Which is the common feature between cardiac and smooth muscles?

• A. Voluntary
• B. Involuntary
• C. Branched
• D. Unbranched

Explanation: Both contract without conscious control, cardiac muscle beating rhythmically on its own and smooth muscle working the gut, blood vessels and other hollow organs. They differ in almost everything else: cardiac fibres are branched and striated while smooth fibres are unbranched and non striated, which is why the third and fourth options each apply to one but not both. Only skeletal muscle is voluntary.

3. Which of the following characters is shared by both skeletal and cardiac muscles?

• A. Presence of striation
• B. Involuntary control
• C. Multinucleated fibers
• D. Intercalated discs

Explanation: Both use the same regular arrangement of actin and myosin filaments, so both show cross striations under the microscope. They differ in control, skeletal being voluntary and cardiac involuntary, and intercalated discs and branching belong to cardiac muscle alone. Multinucleated fibres are a skeletal muscle feature.

4. Which of the following muscle types are involuntary in action?

• A. Skeletal and smooth
• B. Skeletal and cardiac
• C. Cardiac and smooth
• D. Smooth muscle only

Explanation: Cardiac muscle beats rhythmically without conscious control and smooth muscle works the gut, blood vessels and other hollow organs automatically, so both are involuntary. Skeletal muscle is the only voluntary type, which eliminates the first two options at once. Smooth muscle alone is too narrow, since it leaves cardiac muscle out.

5. In which of the following combinations, both components have non-striated muscle fibers?

• A. Intestine & biceps
• B. Intestine & blood vessels
• C. Heart & lungs
• D. Stomach & heart

Explanation: The walls of the intestine and of blood vessels both contain smooth muscle, which has no striations and works involuntarily. The biceps is skeletal muscle and the heart is cardiac, and both of those are striated, so any pairing including them fails. Recognising which organ contains which muscle type is the whole of this question.