Autonomic Nervous System Flashcards
T/F The cell bodies of most sympathetic fibers lie in the paravertebral ganglia, which flank either side of the vertebral column as part of the sympathetic trunks
True
T/F The splanchnic nerves contain mostly sympathetic neurons that emerge from the spine but do not synapse in the paravertebral ganglia near the spine
True; I’m not sure I mentioned it in class—and you certainly don’t need it to answer this question— but if you examine the figure on Slide 16 closely, you’ll note that the parasympathetic outflow from the sacral spine is via the parasympathetic pelvic splanchnic nerve. Thus splanchnic nerves serve both branches of the autonomic nervous system
T/F Sympathetic influence stimulates the digestive system, while parasympathetic influence inhibits it
False; this is reversed, in that sympathetic influence inhibits the GI tract
T/F Sympathetic influence stimulates the kidneys, while parasympathetic influence inhibits them
False; the kidneys (and adrenals) lack parasympathetic innervation whatsoever
Typically, the [parasympathetic / sympathetic ] preganglionic fibers are long while the postganglionic fibers are short.
parasympathetic; they run all the way from the spine to the organ, and then they synapse in their ganglia
In the sympathetic nervous system, the [paravertebral / prevertebral ] ganglia are located within the abdominal aortic plexus.
prevertebral; all the paravertebral ganglia are located in the sympathetic trunk
The _________________ division is another name for the sympathetic division, since sympathetic fibers emerge from the CNS at spinal cord segments T1 through L2.
thoracolumbar
The _________________ division is another name for the parasympathetic division, since parasympathetic fibers emerge from the CNS via some cranial nerves and at spinal cord segments S2 to S4.
craniosacral
The _______________________ nervous system is responsible for what is colloquially termed the “rest-and-digest” response
parasympathetic
Which ONE of the following is NOT TRUE regarding sympathetic fibers?
A. Sympathetic fibers enter the paravertebral ganglia immediately after emerging from the spinal column
B. Some fibers ascend or descend the sympathetic trunk before synapsing in a paravertebral ganglion, and then join the dorsal or ventral ramus at this new level.
C. Some sympathetic fibers synapse immediately in the paravertebral ganglion (i.e., at the same level they entered) and then rejoin the dorsal or ventral ramus at that same level.
D. Some sympathetic fibers enter the paravertebral ganglia but do not synapse there; instead these fibers enter splanchnic nerves and synapse in the prevertebral ganglia near the abdominal aorta.
E. (None, Mr. Silly! All of the above are true about sympathetic fibers.)
E
In Raynaud disease, inappropriate hyper-activation of the sympathetic nervous system has profound effects on the arteries and arterioles of the digits. Based upon your knowledge of sympathetic effects around the body, which ONE of the following would you NOT expect to see during a Raynaud attack?
A. Severe vasoconstriction of digital arterioles
B. Pallor in the digits
C. Inadequate perfusion of the digits
D. Anhidrosis along with relaxation of arrector pili muscles on the palmar fingertips
E. The patient’s fingertips feel very cold, both to observers and to the patient themself
F. (None. All of the above are expected symptoms during a Raynaud attack)
D. Since this is hyperactivation of the sympathetic nervous system, instead of anhidrosis you should see diaphoresis (hyperhidrosis)- sweaty palms, etc.
Horner Syndrome is a condition caused by loss of sympathetic influence to the head. Recall that sympathetic neurons servicing the head emerge as nerves from the thoracic spinal cord. Impingement, trauma, or severance of these nerves can all cause this condition. The result is an absence of sympathetic influence on the affected side of the head, leading to certain clinical signs on that side. Based upon your knowledge of sympathetic effects on body tissues (such as in the tables below), which ONE of the following would you NOT expect to be a symptom of Horner Syndrome? Hint: Remember that Horner Syndrome arises from a lack of sympathetic influence on that side of the head. The affected side of the head would NOT show…
A. Anhidrosis- a lack of sweating
B. Blepharoptosis- a drooping of the upper eyelid due to paralysis of the superior tarsal muscle
C. Miosis- constricted pupils due to contraction of the iridial concentric muscles
D. Goosebumps- goosebumps on face due to contraction of arrector pili muscles
E. Facial flushing- due to vasodilation of facial blood vessels, since there is no sympathetic vasoconstriction to oppose the vasodilation
F. (None. All of the above are expected symptoms of Horner Syndrome)
D. A “synthesis” type question which was not in the notes. I put it in so you could see that the signs
of such a lack of sympathetic activity are entirely logical if you understand the sympathetic nervous system. Similar symptoms might occur with adrenergic antagonist drugs.
Sympathetic & Parasympathetic Responses:
Organ: Eyes
Action: Effect on pupillary diameter
Inc-Dec
Sympathetic & Parasympathetic Responses:
Organ: Heart
Action: Heart rate
Inc-Dec
Sympathetic & Parasympathetic Responses:
Organ: Adrenal medulla
Action: Rate of E/NE release
Inc-No
