Question

Normal activities of the heart are regulated by _________.

• A. Brian
• B. Spinal cord
• C. Modified cardiac muscles
• D. Hormones

Answer 1

Answer: (C)

Modified cardiac muscles

• The muscle cells which are present in the heart are called cardiac muscles. These are the modified involuntary muscles.
• Cardiac muscles have the property of both the striated muscles and smooth muscles.
• They are striated muscles with single nuclei. The muscle fibres are fused and intercalated discs are present.
• Cardiac muscle is highly resistant to fatigue due to the rich supply of special blood vessels.
• Thus, cardiac muscles continuously contract and relax and regulate the functions of the heart.
• So, the correct answer is option C.