Which of the following correctly identifies the sequence of components in a typical spinal reflex arc?

• A. Receptor → Sensory neuron → Integration center → Motor neuron → Effector
• B. Effector → Motor neuron → Integration center → Sensory neuron → Receptor
• C. Integration center → Sensory neuron → Receptor → Motor neuron → Effector
• D. Sensory neuron → Receptor → Integration center → Effector → Motor neuron

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the concept of a spinal reflex arc. A spinal reflex arc is a neural pathway that controls reflex actions. It involves a sequence of components that work together to produce a rapid, involuntary response to a stimulus.
2. Step 2: Identify the components of the spinal reflex arc. These include: (1) Receptor, which detects the stimulus; (2) Sensory neuron, which transmits the signal to the central nervous system; (3) Integration center, typically located in the spinal cord, where the signal is processed; (4) Motor neuron, which carries the response signal to the effector; and (5) Effector, which performs the response action.
3. Step 3: Analyze the sequence provided in the problem. Compare each option to the correct order of components in a spinal reflex arc: Receptor → Sensory neuron → Integration center → Motor neuron → Effector.
4. Step 4: Eliminate incorrect options by checking the logical flow of the reflex arc. For example, the effector cannot precede the motor neuron, as the motor neuron is responsible for transmitting the signal to the effector.
5. Step 5: Select the option that matches the correct sequence of components in the spinal reflex arc: Receptor → Sensory neuron → Integration center → Motor neuron → Effector.