ANS

Question 1

Which cranial nerves carry autonomic afferent information?

Answer 1

CN VII, IX, and X.

Question 2

Information entering the brainstem via cranial nerves converges where?

Answer 2

On the solitary nucleus.

Question 3

In terms of autonomic functions, what role does the medulla play?

Answer 3

Regulation of heart rate, respiration, vasoconstriction and vasodilation.

Question 4

Where are the cell bodies for sympathetic preganglionic neurons?

Answer 4

In the lateral horn of the spinal cord, from T1 to L2.

Question 5

How does sympathetic innervation reach the head?

Answer 5

Preganglionic sympathetic fibers exiting from T1 (the first level for sympathetic innervation) also travel to the superior, middle, and stellate ganglia, whose post ganglionic fibers then go on to the head.

Question 6

True or false: All of the preganglionic sympathetic fibers synapse on a ganglion in the paravertebral region.

Answer 6

False. Fibers destined for the stomach, liver, pancreas, and intestine do not synapse on ganglia until closer to the organ. Fibers destined for the adrenal medulla do not synapse on a ganglion at all.

Question 7

What does NE binding to alpha receptors in skeletal muscle accomplish?

Answer 7

Vasoconstriction, to prevent blood pooling when a person stands up. Blood pooling can cause a person to faint.

Question 8

What is the effect of an alpha-adrenergic receptor blocker in blood vessels?

Answer 8

It blocks the action of NE (NE causes vasoconstriction) to help decrease blood pressure.

Question 9

What is the effect of an beta1-adrenergic receptor blocker?

Answer 9

They decrease heart rate and contractiity.

Question 10

What is the effect of an beta2-adrenergic receptor agonist?

Answer 10

They prevent bronchoconstriction.

Question 11

Which cranial nerves carry parasympathetic efferent information?

Answer 11

CN III, VII, IX, and X.

Question 12

What do parasympathetic fibers carried by CN III do?

Answer 12

Constrict pupil and increase convexity of the lens.

Question 13

What do parasympathetic fibers carried by CN VII do?

Answer 13

They innervate the salivary glands, and the lacrimal gland.

Question 14

What do parasympathetic fibers carried by CN IX do?

Answer 14

They innervate the salivary glands.

Question 15

True or false: 75% of the parasympathetic fibers in the cranial nerves is in CN X.

Answer 15

True.

Question 16

Where are the cell bodies for non-cranial parasympathetic preganglionic neurons?

Answer 16

In the lateral horn of S2-S4.

Question 17

What are the symptoms of Horner’s syndrome?

Answer 17

Drooping of the upper eyelid, constriction of the pupil, absence of sweating on the face and neck.
(Ptosis, miosis, anhidrosis.)

Question 18

What causes Horner’s syndrome?

Answer 18

Preganglionic causes: Cerebral vascular accident, MS, pituitary tumor, Pancoast tumor (tumor on apex of lung), mediastinal mass, neck trauma, coronary bypass surgery, thyroidectomy.
Post ganglionic: head or neck trauma, migraine, cluster headache, herpes zoster, ICA dissection.

Question 19

What type of receptors react to NE and epinephrine?

Answer 19

Alpha and beta adrenergic.

Question 20

True or false: both NE and epinephrine have equal affinity for both alpha and beta adrenergic receptors.

Answer 20

False. NE has greater affinity for alpha receptors. Epinephrine does indeed have equal affinity for both.

Question 21

How would you determine if miosis is due to Horner’s syndrome or not?

Answer 21

Classic model: Using cocaine drops would cause a non-Horner’s pupil to dilate as cocaine blocks NE reuptake. A Horner’s pupil would not dilate in response to these drops as there is a lesion preventing NE from being released at all.
Current model: Using apraclonidine (an adrenergic agonist) will cause hyper-sensitive Horner’s case receptors to dilate, but not non-Horner’s cases.

Question 22

How would you determine if a lesion causing Horner’s syndrome is preganglionic vs postganglionic?

Answer 22

Using hydroxamphetamine stimulates the release of NE. In the case of a preganglionic lesion, the postganglionic cell can still release NE (it just doesn’t get that signal from the sympathetic pathway anymore). In the case of a post ganglionic lesion, the postganglionic cell cannot release NE.
Hence, dilation indicates a preganglionic lesion, no dilation indicates a postganglionic lesion.

Question 23

In the arteries, what is the sympathetic effect?

Answer 23

Alpha constricts

Beta dilates.

Question 24

In the arteries, what is the parasympathetic effect?

Answer 24

None.

Question 25

In the ciliary muscle, what is the sympathetic effect?

Answer 25

Beta2, possible slight relaxation.

Question 26

In the ciliary muscle, what is the parasympathetic effect?

Answer 26

Muscarinic, contraction.

Question 27

In the pupil, what is the sympathetic effect?

Answer 27

Alpha1, dilation.

Question 28

In the pupil, what is the parasympathetic effect?

Answer 28

Muscarinic, constriction.

Question 29

In the lacrimal gland, what is the sympathetic effect?

Answer 29

Alpha, slight decreased tear production due to blood vessel constriction.

Question 30

In the lacrimal gland, what is the parasympathetic effect?

Answer 30

Muscarinic, increased tear production.

Question 31

In the salivary gland, what is the sympathetic effect?

Answer 31

Alpha1, blood vessel constriction, slight viscous saliva production.

Question 32

In the salivary gland, what is the parasympathetic effect?

Answer 32

Muscarinic, blood vessel dilation, thin saliva production.

Question 33

In the heart, what is the sympathetic effect?

Answer 33

Beta1 and Beta2, increased contraction force.

Beta1: increased heart rate

Question 34

In the heart, what is the parasympathetic effect?

Answer 34

Muscarinic, decreased rate of contraction.

Question 35

In the lungs, what is the sympathetic effect?

Answer 35

Beta2: dilates air passageways.

Question 36

In the lungs, what is the parasympathetic effect?

Answer 36

Muscarinic, constricts air passageways.