ANS and Neurogenic Bladder Flashcards
Length of intermediolateral cell column
Which fibers go the head and neck?
T1-L2
T1-T3
Rostral ventrolateral medulla is involved in:
Baroreceptor reflex and BP maintenance
Medullary raphe is involved in:
Skin vasoconstriction and responses to cold.
Paraventricular nucleus (PVN) and lateral hypothalamus is involved in:
Responses to stress
What is the major distribution center for SNS in head/neck? What level is it?
Superior cervical ganglion C4.
Fibers enter via ____ rami communicant and leave via ____ rami comunicant.
White, gray
Pupillary constriction pathway
CN II –> EWN –> CN III –> ciliary ganglion –> ciliary m. –> miosis
Lesion of CN II afferent defects:
IL direct reflex and CL consensual reflex
Lesion of CN III and/or ciliary ganglion efferent defects
Large dilated pupil in affected eye. Does not respond to light when shined.
Superior salivatory nucleus is the origin of which CN?
Where does this nerve synapse? To do what?
CN VII.
Synapse in sphenopalatine ganglion –> lacrimal gland.
Synapse in submandibular ganglion –> submandibular/sublingual glands.
Inferior salivatory nucleus is the origin of which CN?
Where does this nerve synapse? To do what?
CN IX.
Synapse in otic ganglion –> parotid gland.
3 causes of Horner syndrome
- Central lesion: lateral brainstem and upper cervical SC.
- Preganglionic lesion (2nd neuron): lesion in sympathetic chain or tumor in apex of lung.
- Postganglionic lesion/superior cervical ganglion (3rd neuron): compressed in internal carotid a. Or mass in cavernous sinus.
Central/pre-ganglionic lesion symptoms Facial sweating: Response to drugs that cause release of NE: Response to direct alpha-agonists (epi): Location of lesion:
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
Post-ganglionic lesion symptoms Facial sweating: Response to drugs that cause release of NE: Response to direct alpha-agonists (epi): Location of lesion:
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
Orthostatic hypotension
Decreases in arterial pressure when standing from sitting/laying position.
Innervations of carotid sinus and aortic arch:
What do they respond to?
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.
Baroreceptor reflex w/ high BP
- Stretch of baroreceptors.
- Nucleus solitarius of medulla.
- Excitatory signals to nucleus ambiguus.
- NA can either inhibit the SA node –> bradycardia OR inhibit rostral ventrolateral medulla which inhibits SNS activity.
Baroreceptor afferent lesion causes:
Fluctuating hypertension
Baroreceptor efferent lesion causes:
Fluctuating hypotension
What prevents the voiding?
SNS from lumbar SC T12-L2 and travel in Sacral Splanchnic n./Hypogastric n.
What allows voiding?
PSNS from sacral micturition center (S2-S4) that travel in pelvic splanchnic n.
Once bladder is filled to threshold, where are the afferents sent?
PAG in midbrain.
PAG projects to pontine micturition center (PMC) in pons.
Once afferents reach the PMC, what 2 things must occur?
- Excitatory signals sent to sacral PSNS nucleus.
2. Inhibition of Onuf nucleus.
Voluntary control of voiding pathway
Medial frontal cortex sends inhibition to PMC.
Motor axons from onuf nucleus project through pudendal n. to innervate EUS and pelvic floor.
Neurogenic bladders and their symptoms:
Uninhibited
Spastic
Flaccid
Uninhibited - incontinence and urgency
Spastic - urgengy and incontinence
Flaccid - retention and overflow incontinence
What causes uninhibited bladder?
Medial frontal cortex cannot inhibit the PMC
What causes spastic bladder?
What are the consequnces?
Lesions in lower brainstem or SC above conus medularis.
No pons control.
Increase intravesical pressure that leads to hypertrophy and reduction of bladder volume.
Where is the lesion in flaccid paralysis?
Conus medullaris or cauda equina.
Which neurogenic bladder is associated with a loss in anal reflex?
Flaccid bladder
