Jenny is running for more than an hour on a pleasant sunny morning. her body is sweating to maintain homeostasis, which is caused by the action of a/an
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answer:

a possibility is  vasodilation.

"sweat  secretion stops when body temperature returns to normal. blood vessels supplying blood to the skin can swell or dilate - called  vasodilation."

"to maintain homeostasis, the blood vessels in your skin dilate to allow more blood flow to the surface of your body where it disperses the heat. you won’t feel the vasodilation, but you certainly will feel yourself sweating."

explanation: