Startled Suzie
 Suzie was walking down the street. Suzie was nearly hit by a car. Suzie
narrowly avoided the car, but as she moved out of the way, she stepped
on a tack. How did Suzie’s Nervous System handle these events?
The Limbic
System's response
activates the
sympathetic
nervous system's
flight response.
This causes
Suzie to move
quickly away
from the danger
of car.
The immediate response is
a spinal withdraw reflex.
Suzie steps on
a nail activating
nociceptors
by sending a
response up the
spinothalamic
pathway of the
spinal cord.
This is an involuntary reflex
produced by the spinal
cord.
The hamstring muscle
group of the leg that Suzie
has injured will
automatically flex,
meanwhile the quadricep
muscle group of that same
leg will stop performing its
antagonist function
allowing the leg to quickly
recoil away from the painful
stimulus.
Initial Response/Reflexes to
Immediately Protect Suzie
Meanwhile, the
contralateral leg is
receiving a crossextension reflex
from the spinal
cord indicating
that the
quadricep muscle
group of this leg
should extend to
allow Suzie to
keep her balance
and not fall.
Suzie’s Limbic System has
activated the
Sympathetic Nervous
System. She has a vast
amount of
norepinephrine coursing
through her blood
stream causing things
like dilated pupils,
increased heart rate,
increased blood
pressure, and increased
respiratory rate.
Nociceptors are
still sending pain
signals up the
spinothalamic
and fasciculus
gracilis pathways
to the thalamus.
Once they arrive
at the thalamus,
they will be
rerouted to the
post-central gyrus
of the parietal
lobe for analysis.
After analysis
of this pain
sensation,
the parietal
lobe will
relay what it
has learned
to the frontal
lobe for
higher level
processing
and to
develop a
finer motor
response.
In the pre-central
gyrus, a voluntary
motor response
will be developed
and relayed to the
thalamus. The
thalamus will relay
this impulse down
the spinal cord via
the corticospinal
pathway to allow
Suzie voluntary
muscle control
over the situation.
Meanwhile, Suzie’s
vestibulocochlear
nerve has been
analyzing her
semicircular canals
in order to help her
with her balance.
Also her cerebellum
has been analyzing
this event to allow
for smooth
coordination of her
muscular
movements
Meanwhile a more fine-tuned response is being
produced by Suzie’s Brain for the aftermath of this
scenario.
.
Finally, once Suzie
is out of danger
and has
completed her full
fine-tuned
response to this
event, her
hypothalamus will
begin activating
the necessary
response from her
endocrine system
to return her to
normal
homeostasis.