If a person touches a hot surface and quickly pulls their hand away, which type of nerves are primarily responsible for sending the signal to move the hand?

Appeared in: RRB Nsg. Superintendent-2026 (Shift -3rd)

Explanation

The question asks which nerves send the signal to move the hand away from a painful stimulus.
This action is part of a withdrawal reflex, a protective response mediated by the nervous system.
Motor nerves, also known as efferent nerves, are responsible for carrying signals from the central nervous system (in this case, the spinal cord) to the effector muscles.
The arrival of this signal at the muscle causes it to contract, resulting in the movement of the hand away from the hot surface.

Option B: Interneurons are located entirely within the central nervous system (brain and spinal cord). They act as connectors, relaying signals between sensory neurons and motor neurons, but they do not directly transmit signals to the muscles.
Option C: Autonomic nerves regulate involuntary bodily functions such as heart rate, digestion, and glandular secretions. They do not control the voluntary skeletal muscles involved in moving the hand.
Option D: Sensory nerves, or afferent nerves, transmit signals from the sensory receptors (e.g., in the skin) to the central nervous system. They carry the initial pain signal but do not carry the command to move the muscle.

Visual 1: Diagram: A flowchart illustrating the pathway of a simple withdrawal reflex arc, showing the sensory receptor, sensory neuron, interneuron in the spinal cord, motor neuron, and effector muscle.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Withdrawal Reflex and Neural Pathways as background academic context rather than a clinical decision trigger.
Assessing reflex responses is a fundamental part of a neurological examination. An absent, diminished, or exaggerated reflex can indicate damage or disease affecting the central or peripheral nervous system.
Patient safety is a key concern for individuals with impaired sensory or motor function (e.g., diabetic neuropathy, spinal cord injury). They may not be able to sense a harmful stimulus or react appropriately, increasing their risk for burns, pressure injuries, and other trauma.
What if? If a patient has a spinal cord injury that severs the connection between the brain and the motor neurons below the injury level, the withdrawal reflex might still be present (as it's mediated at the spinal cord level), but the person would not feel the stimulus and would have no voluntary control over the movement.

How to Approach the Question

First, identify the core process described in the question: a stimulus (touching a hot surface) leads to a response (pulling the hand away). This is a classic reflex action.
Break down the reflex pathway into its components: stimulus detection, signal to the CNS, processing in the CNS, and signal to the muscle for action.
Analyze the function of each nerve type provided in the options.
Match the specific part of the pathway asked in the question ('sending the signal to move the hand') with the correct nerve type.
Sensory nerves send signals to the CNS. Motor nerves send signals from the CNS to cause movement. Interneurons connect them within the CNS. Autonomic nerves control internal organs.
Therefore, the nerves that send the signal to move are the motor nerves.

Concept Tested & Keywords

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Practise the full RRB Nsg. Superintendent-2026 (Shift -3rd)

Attempt every question from this paper in a timed mock, then review the full solution for each one.