Which stage of a reflex arc would be significantly different in a reflex that is initiated by the brain compared to a reflex that is initiated by the spinal cord?

• A. Stage 1- Receptor.
• B. Stage 2- Sensory neuron.
• C. Stage 3- Integration center.
• D. Stage 4- Motor Neuron.
• E. Stage 5- Effector.

Answer: (C)

Verified step by step guidance

1. Understand the concept of a reflex arc: A reflex arc is a neural pathway that controls a reflex action. It typically involves five stages: receptor, sensory neuron, integration center, motor neuron, and effector.
2. Identify the role of the integration center: The integration center is where the sensory information is processed and a response is generated. In a spinal reflex, this occurs in the spinal cord, while in a brain-initiated reflex, it occurs in the brain.
3. Compare the integration centers: In a spinal reflex, the integration center is located in the spinal cord, allowing for a quick response without involving the brain. In contrast, a brain-initiated reflex involves the brain as the integration center, which may result in a more complex response.
4. Analyze the impact of the integration center's location: The location of the integration center affects the speed and complexity of the reflex. Spinal reflexes are typically faster and simpler, while brain-initiated reflexes can be slower but more complex due to higher-level processing.
5. Conclude that the integration center is the stage that differs significantly: Since the integration center's location (spinal cord vs. brain) is the key difference between spinal and brain-initiated reflexes, Stage 3 - Integration center is the correct answer.