Video Transcript
The table provided shows the effect
of the parasympathetic and sympathetic nervous systems on some major organs and
glands. The adrenal medulla is part of the
adrenal gland that produces adrenaline and noradrenaline. What effect does the sympathetic
nervous system have on the adrenal medulla? (A) Activation of the adrenal
medulla. (B) Inhibition of the adrenal
medulla. (C) No effect on the adrenal
medulla.
This question is asking us to
recall the function of the sympathetic nervous system and how it affects the
functions of the major organs and glands. So to answer this question, let’s
review what we know about the sympathetic nervous system and its specific impact on
the organs like the adrenal gland.
You may recall that the autonomic
nervous system is the part of the peripheral nervous system that is responsible for
the involuntary motor functions of the body. There are two subdivisions of the
autonomic nervous system that work in opposition to one another: the sympathetic and
parasympathetic nervous systems.
The parasympathetic nervous system
is active during times of rest, relaxation, and feeding, so its responses are called
the rest-and-digest responses. In contrast, the sympathetic
nervous system takes over in times of stress when the body is preparing for action,
so its responses are termed the fight-or-flight responses.
So, if the goal of the nervous
response is to decrease activity, the responses are under the control of the
parasympathetic nervous system, while if the goal of the nervous system is to
increase activity, it is the sympathetic nervous system that is in control of
responses.
We can use the knowledge we just
recalled about the actions of the sympathetic and parasympathetic nervous systems to
complete the table for the adrenal medulla. As we just reviewed, the goal of
the parasympathetic nervous system is to decrease activity, so the effect of the
parasympathetic nervous system on the adrenal medulla would be to decrease
activity.
From the question, we know that the
adrenal medulla produces adrenaline and noradrenaline. So, a reduction in activity would
mean the adrenal medulla would reduce or inhibit production of adrenaline and
noradrenaline.
Also from what we reviewed, we know
that the goal of the sympathetic nervous system is to increase activity. So the effect of the sympathetic
nervous system on the adrenal medulla would be to increase activity. Therefore, when the sympathetic
nervous system takes over, the adrenal medulla is activated, triggering the
production of adrenaline and noradrenaline, resulting in the body’s fight-or-flight
responses.
With this information, we are now
ready to answer the question. The effect of the sympathetic
nervous system on the adrenal medulla is activation of the adrenal medulla.