A student runs a 400-metre race and notices their heart rate increases rapidly. Which hormone is primarily responsible for this response?

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Question

A student runs a 400-metre race and notices their heart rate increases rapidly. Which hormone is primarily responsible for this response?

Accepted Answer

C. Adrenaline — Adrenaline is secreted by the adrenal medulla (inner part of the adrenal glands) in response to stress or exercise. It increases heart rate, dilates airways, and redirects blood to muscles as part of the 'fight or flight' response.

Answer

B. Oestrogen

Answer

C. Adrenaline

Answer

D. Thyroxine

Answer

A. Insulin

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