The adrenal medulla is responsible for secreting adrenaline into the bloodstream, which is responsible for the hormonal response in the fight or flight response. In the fight or flight response, also known as the adrenaline response, the amygdala is activated from fear or anxiety, and it then activates the sympathetic nervous system. The sympathetic nervous system then activates the adrenal medulla to secrete adrenaline into the bloodstream. The circulating adrenaline in turn causes an increase in heart rate, increase in blood pressure, and dilates the bronchioles (air sacs) in the lungs, which are the physical symptoms of the adrenaline response.
