Question

A hormone called ____________ overrides the normal sinus rhythm causing the heart to beat faster during the "fight or flight" response.

Answer 1

Epinephrine.

Step-by-step explanation:

Epinephrine is also known as adrenaline hormone. This hormone can also acts as a neurotransmitter. Epinephrine hormone is released from the adrenal glands.

Epinephrine mainly release at the time fear, stress and prepares the body for the fight or flight response. This hormone increases the heart beat of an individual by overriding the normal sinus rhythm of the heart.

Thus, the answer is epinephrine.

Answer 2

Adrenaline. Adrenaline, also known as epinephrine, is a hormone secreted in the medulla of the adrenal glands and in some neurons of the central nervous system after receiving a message from the brain that a stressful situation is currently occurring. This hormone is then release to the bloodstream which, in turn, targets muscles and glands, causing the body to speed up and become tense, as well as more alert.