**Question:** Dorsal root ganglia have

A. sensory neurons
B. autonomic neurons
C. motor neurons
D. mixed neurons

**Core Concept:**

Dorsal root ganglia are a group of neurons that form part of the peripheral nervous system. They are located between the spinal cord and the skin, receiving sensory information and conducting it to the spinal cord for further processing. The correct answer to this question is "A. sensory neurons" because they are responsible for transmitting sensory information from the body to the central nervous system (CNS).

**Why the Correct Answer is Right:**

Dorsal root ganglia are specialized in the processing of sensory information, particularly pain, temperature, pressure, and proprioception. Sensory neurons, also known as afferent neurons, carry this information to the spinal cord, where it is integrated with other sensory inputs and processed by the central nervous system. This allows the body to respond appropriately to stimuli and maintain homeostasis.

**Why Each Wrong Option is Incorrect:**

1. **B. autonomic neurons**: Autonomic neurons, also known as efferent neurons, are involved in the control of involuntary functions, such as the sympathetic and parasympathetic systems. They are not part of the dorsal root ganglia.
2. **C. motor neurons**: Motor neurons, also known as efferent neurons, are associated with the transmission of motor signals from the spinal cord to the muscles, enabling voluntary movements. They are not part of the dorsal root ganglia.
3. **D. mixed neurons**: While dorsal root ganglia contain both sensory and motor neurons, the term "mixed neurons" is not accurate as it does not specifically differentiate between sensory and motor neurons. The correct answer is A, sensory neurons, which accurately describes the primary function of dorsal root ganglia.

**Clinical Pearl:**

Understanding the role of dorsal root ganglia and sensory neurons is crucial for interpreting neurological examinations and diagnosing various neurological conditions. For example, a patient with a lesion affecting the sensory neurons could present with pain, temperature, and proprioception deficits, while a lesion affecting motor neurons would result in motor deficits. This knowledge is essential for making an accurate diagnosis and formulating an appropriate treatment plan.