After 10 inches of rain in less than 12 hours, floodwaters are about to inundate kara's house. she has only a few minutes to grab her dog and whatever belongings she can carry before she must evacuate. kara's is/are releasing epinephrine and norepinephrine to prepare her for fight or flight.

Both epinephrine and norepinephrine are released by the adrenal medulla and they circulate a neurotransmitters and hormones throughout the nervous system and circulatory system. Kara's  adrenal medulla is releasing ephinephrine and norepinephrine to prepare her for fight or flight.

Explanation:

Epinephrine and norepinephrine are neurotransmitters and they belong to a class of compounds called catecholamines.  While chemically both these neurotransmitters are very similar, they have different functions. Norepinephrine has an effect only on alpha receptors in your arteries, while epinephrine works of both alpha and beta receptors. Beta receptors are in the heart, lungs, and the arteries of the muscles in our skeletal system as well.  Both compounds also serve as hormones in the body and having either an overabundance or a deficiency of these compounds can affect your health.  Epinephrine can increase your heart rate and smooth out or relax the muscles of your breathing passages so you breathe better when experiencing a fight or flight response. Norepinephrine can constrict your blood vessels and increase blood pressure getting your body ready for action. It is also used to treat very low blood pressure.  

explanation:

may i ask what challenges?

answer; negative punishment;