Which category of neurons convert the external stimuli to internal impulses?

Options

A. Afferent neurons
B. Efferent neurons
C. Connector neurons
D. Both (b) and (c)

Explanation

**Step-by-Step Solution:**

1. **Understanding Neurons**: Neurons are specialized cells that transmit nerve impulses. They play a crucial role in the nervous system by facilitating communication within the body.

2. **Categories of Neurons**: There are three main categories of neurons:
- **Sensory Neurons**: These neurons carry signals from sensory organs to the central nervous system (CNS).
- **Efferent Neurons (Motor Neurons)**: These neurons transmit signals from the CNS to muscles or glands.
- **Interneurons (Connecting Neurons)**: These neurons connect sensory and motor neurons within the CNS.

3. **Identifying the Function**: The question asks which category of neurons converts external stimuli to internal impulses. This means we are looking for neurons that take information from the environment and send it to the CNS.

4. **Analyzing the Options**:
- **Option 1: Efferent Neurons** - These transmit impulses from the CNS to muscles or glands, not from external stimuli to the CNS. Therefore, this option is incorrect.
- **Option 2: Afferent Neurons** - These are the correct type of neurons that carry signals from sensory organs to the CNS, converting external stimuli into internal impulses.
- **Option 3: Connecting Neurons** - These connect different neurons within the CNS but do not convert external stimuli to internal impulses. Thus, this option is incorrect.
- **Option 4: B and C** - This option is also incorrect as it combines the wrong categories.

5. **Conclusion**: The correct answer is **Afferent Neurons**, as they are responsible for converting external stimuli into internal impulses.

**Final Answer**: Afferent Neurons

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