Video Transcript
State the adrenal hormone being
described. Released from the adrenal medulla,
this hormone narrows blood vessels to nonessential organs to direct more blood to
the heart and muscles in the fight-or-flight response. (A) Aldosterone; (B) cortisol; (C)
noradrenaline, norepinephrine; or (D) progesterone.
This question asks us about a
hormone secreted from the adrenal medulla, which is the inner region of the adrenal
gland. Our adrenal glands are two
endocrine organs found just on top of the kidneys in the human body. Endocrine glands are responsible
for releasing hormones into the bloodstream.
Our question asks us specifically
about the adrenal medulla, which generally secretes hormones that are not imperative
for survival but are significant in our responses to stress. The fight-or-flight response refers
to the quick decision-making that occurs when an individual experiences a
high-stress environment. Changes that typically occur in the
body during this response include an increase in heart rate and increase in blood
flow to skeletal muscles, so the body is ready to run or fight, and an increase in
cellular respiration, so more energy is available for quick movement.
The adrenal medulla is responsible
for secreting two hormones that cause these changes. One of these hormones is
adrenaline, also referred to as epinephrine. A second hormone secreted is
noradrenaline, also referred to as norepinephrine. In the fight-or-flight response,
noradrenaline causes the dilation of pupils and the constriction of blood vessels to
nonessential organs. The redirection of blood from
nonessential organs to those that are essential, like the heart and skeletal muscle,
is significant for the stress response, as it allows the body to move quickly away
from danger. The widening of pupils is also
beneficial, as a person will be able to see a potential danger better.
Adrenaline works alongside
noradrenaline to prepare the body in stressful situations. But adrenaline is not an answer
choice for this question. So we can be sure that the correct
answer is noradrenaline. Therefore, the hormone secreted by
the adrenal medulla that is responsible for narrowing blood vessels to nonessential
organs is (C), noradrenaline, norepinephrine.
