Question

when the flexor muscles of one arm contract in a withdrawal reflex, the extensor muscles of the other arm contract. what is this response called? multiple choice crossed flexor reflex flexor extensor reflex ipsilateral reflex crossed extensor reflex

Explanation:

In a withdrawal reflex, when flexor muscles of one limb (e.g., arm) contract to withdraw from a stimulus, the extensor muscles of the opposite (contralateral) limb contract to maintain posture/balance. This is the Crossed Extensor Reflex (the reflex involves crossing to the opposite side, with extensors activating there). The "crossed" refers to the reflex affecting the opposite limb, and "extensor" because extensors of the other limb contract. Other options: "Crossed flexor reflex" would imply flexors on the opposite side (incorrect), "Flexor extensor reflex" is not a standard term, "Ipsilateral reflex" would be same - side (but this reflex is contralateral), so the correct is Crossed extensor reflex.

Answer:

A. Crossed flexor reflex (Wait, correction: The correct term for when flexors of one limb contract (withdrawal) and extensors of the opposite limb contract (to maintain balance) is the Crossed Extensor Reflex. But looking at the options, there's "Crossed flexor reflex" (maybe a typo in options, but more accurately, the correct reflex here is the Crossed Extensor Reflex, but if we go by the options given: Wait, the options are:

1. Crossed flexor reflex

1. Flexor extensor reflex

1. Ipsilateral reflex

1. Crossed extensor reflex

Ah, the fourth option is "Crossed extensor reflex". So the correct answer is:

D. Crossed extensor reflex (assuming the last option is D, as per the order: first option is Crossed flexor reflex, then Flexor extensor reflex, then Ipsilateral reflex, then Crossed extensor reflex)