Question

if a bee sting on the right thigh causes a quick involuntary reaction of the right arm, this would be an example of a(n) ______ reflex.

multiple choice

bilateral

intersegmental

withdrawal

crossed extensor

contralateral

Explanation:

• Bilateral: Involves both sides of the body symmetrically. Not the case here as it's the same - side (right thigh and right arm).
• Intersegmental: Refers to involving different spinal segments. This is not the key characteristic here.
• Withdrawal: Usually a local response to remove a body part from a stimulus. But here, it's a more complex response across different body parts on the same side.
• Crossed - extensor: Typically involves one side flexing and the other extending in a contralateral (opposite - side) manner. Not relevant here.
• Contralateral: Means opposite - side. But in this case, the stimulus (right thigh) and response (right arm) are on the same side. However, the key is that it's an intersegmental reflex. An intersegmental reflex is one that involves multiple spinal segments. The bee sting on the thigh (innervated by lower spinal segments) causing a reaction in the arm (innervated by higher spinal segments) shows that signals are traveling across different spinal segments.

Answer:

intersegmental