Question

Which muscles act involuntarily?
(i) Striated muscles
(ii) Smooth muscles
(iii) Cardiac muscles
(iv) Skeletal muscles

• A. (i) and (ii)
• B. (ii) and (iii)
• C. (iii) and (iv)
• D. (i) and (iv)

Answer 1

The correct option is B

(ii) and (iii)

The correct option is B

Explanation of the correct option:

1. Smooth muscles are generally located in the wall of visceral organs. They do not work according to our will that is why they don't act like voluntary muscles.
2. They are basically involved in the peristaltic movement of the gastrointestinal tract.
3. Cardiac muscles are located in the heart they contract and relax rapidly and they help to transfer the blood to different parts of the body.

Explanation of the incorrect options:

Option A

Striated muscle is a muscle that features repeating functional units called sarcomeres. Smooth muscles act involuntarily so this option is an incorrect option.

Option C

Cardiac muscles act as involuntarily, thus, this option is incorrect.

Option D

Striated and skeletal muscles act as voluntary muscles and muscles move according to our will.

Final Answer: Therefore the correct answer is options (b) ii and iii i.e smooth and cardiac muscles are the muscles that act involuntarily.