ANS and Neurogenic Bladder

Question 1

Length of intermediolateral cell column

Which fibers go the head and neck?

Answer 1

T1-L2

T1-T3

Question 2

Rostral ventrolateral medulla is involved in:

Answer 2

Baroreceptor reflex and BP maintenance

Question 3

Medullary raphe is involved in:

Answer 3

Skin vasoconstriction and responses to cold.

Question 4

Paraventricular nucleus (PVN) and lateral hypothalamus is involved in:

Answer 4

Responses to stress

Question 5

What is the major distribution center for SNS in head/neck? What level is it?

Answer 5

Superior cervical ganglion C4.

Question 6

Fibers enter via ____ rami communicant and leave via ____ rami comunicant.

Answer 6

White, gray

Question 7

Pupillary constriction pathway

Answer 7

CN II –> EWN –> CN III –> ciliary ganglion –> ciliary m. –> miosis

Question 8

Lesion of CN II afferent defects:

Answer 8

IL direct reflex and CL consensual reflex

Question 9

Lesion of CN III and/or ciliary ganglion efferent defects

Answer 9

Large dilated pupil in affected eye. Does not respond to light when shined.

Question 10

Superior salivatory nucleus is the origin of which CN?

Where does this nerve synapse? To do what?

Answer 10

CN VII.
Synapse in sphenopalatine ganglion –> lacrimal gland.
Synapse in submandibular ganglion –> submandibular/sublingual glands.

Question 11

Inferior salivatory nucleus is the origin of which CN?

Where does this nerve synapse? To do what?

Answer 11

CN IX.

Synapse in otic ganglion –> parotid gland.

Question 12

3 causes of Horner syndrome

Answer 12

1. Central lesion: lateral brainstem and upper cervical SC.
2. Preganglionic lesion (2nd neuron): lesion in sympathetic chain or tumor in apex of lung.
3. Postganglionic lesion/superior cervical ganglion (3rd neuron): compressed in internal carotid a. Or mass in cavernous sinus.

Question 13

Central/pre-ganglionic lesion symptoms 
Facial sweating:
Response to drugs that cause release of NE:
Response to direct alpha-agonists (epi):
Location of lesion:

Answer 13

Facial sweating: anhidrosis
Response to drugs that cause release of NE: pupil dilation
Response to direct alpha-agonists (epi): no pupil dilation
Location of lesion: hypothalamus, dorsolateral medulla, SC

Question 14

Post-ganglionic lesion symptoms
Facial sweating:
Response to drugs that cause release of NE:
Response to direct alpha-agonists (epi):
Location of lesion:

Answer 14

Facial sweating: normal
Response to drugs that cause release of NE: no pupil dilation
Response to direct alpha-agonists (epi): exagerrated pupil dilation
Location of lesion: superior cervical ganglion or cavernous sinus

Question 15

Orthostatic hypotension

Answer 15

Decreases in arterial pressure when standing from sitting/laying position.

Question 16

Innervations of carotid sinus and aortic arch:

What do they respond to?

Answer 16

Carotid sinus: CN IX
Aortic arch: CN X

Carotid sinus can do both increase and decrease in BP, but aortic arch can only respond to increase in BP.

Question 17

Baroreceptor reflex w/ high BP

Answer 17

1. Stretch of baroreceptors.
2. Nucleus solitarius of medulla.
3. Excitatory signals to nucleus ambiguus.
4. NA can either inhibit the SA node –> bradycardia OR inhibit rostral ventrolateral medulla which inhibits SNS activity.

Question 18

Baroreceptor afferent lesion causes:

Answer 18

Fluctuating hypertension

Question 19

Baroreceptor efferent lesion causes:

Answer 19

Fluctuating hypotension

Question 20

What prevents the voiding?

Answer 20

SNS from lumbar SC T12-L2 and travel in Sacral Splanchnic n./Hypogastric n.

Question 21

What allows voiding?

Answer 21

PSNS from sacral micturition center (S2-S4) that travel in pelvic splanchnic n.

Question 22

Once bladder is filled to threshold, where are the afferents sent?

Answer 22

PAG in midbrain.

PAG projects to pontine micturition center (PMC) in pons.

Question 23

Once afferents reach the PMC, what 2 things must occur?

Answer 23

1. Excitatory signals sent to sacral PSNS nucleus.

2. Inhibition of Onuf nucleus.

Question 24

Voluntary control of voiding pathway

Answer 24

Medial frontal cortex sends inhibition to PMC.

Motor axons from onuf nucleus project through pudendal n. to innervate EUS and pelvic floor.

Question 25

Neurogenic bladders and their symptoms:
Uninhibited
Spastic
Flaccid

Answer 25

Uninhibited - incontinence and urgency
Spastic - urgengy and incontinence
Flaccid - retention and overflow incontinence

Question 26

What causes uninhibited bladder?

Answer 26

Medial frontal cortex cannot inhibit the PMC

Question 27

What causes spastic bladder?

What are the consequnces?

Answer 27

Lesions in lower brainstem or SC above conus medularis.
No pons control.
Increase intravesical pressure that leads to hypertrophy and reduction of bladder volume.

Question 28

Where is the lesion in flaccid paralysis?

Answer 28

Conus medullaris or cauda equina.

Question 29

Which neurogenic bladder is associated with a loss in anal reflex?

Answer 29

Flaccid bladder