Reflex Actions: Quick Neural Responses

Steps:

• Recall that a reflex action is an automatic, involuntary response to a stimulus for protection.
• Identify key features: it's fast, bypasses the brain, and uses the spinal cord for coordination.
• Evaluate options by matching against the definition of speed and pathway.
• Select the option that accurately describes both rapidity and spinal cord involvement.

Why A is correct:

• Reflex actions are defined as rapid, involuntary responses to stimuli processed via the spinal cord, enabling quick protection without brain delay.

Why the others are wrong:

• B: Motor neurons transmit signals but do not detect stimuli; detection occurs via sensory neurons.
• C: Reflexes are rapid, not slow, to ensure immediate response.
• D: Reflexes are rapid and involve the spinal cord, not slow detection by motor neurons.

Final answer: A