Cardiac muscles are innervated by_______.

Answer

**Step-by-Step Solution:**

1. **Understanding Cardiac Muscles**: Cardiac muscles are specialized muscle tissues found only in the heart. They are responsible for pumping blood throughout the body.

2. **Innervation of Muscles**: Innervation refers to the supply of nerves to a specific body part. It determines how muscles receive signals to contract or relax.

3. **Types of Nervous System**: The nervous system is divided into two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The PNS is further divided into the somatic nervous system (which controls voluntary movements) and the autonomic nervous system (which controls involuntary functions).

4. **Role of the Autonomic Nervous System**: The autonomic nervous system (ANS) regulates involuntary bodily functions, including heart rate, digestion, and respiratory rate. It operates without conscious control.

5. **Cardiac Muscle Control**: Since cardiac muscles function involuntarily (we do not consciously control our heartbeat), they are innervated by the autonomic nervous system.

6. **Conclusion**: Therefore, the correct answer to the question "Cardiac muscles are innervated by _______" is the autonomic nervous system.

**Final Answer**: Cardiac muscles are innervated by the autonomic nervous system.

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