GA: Autonomics Flashcards
What is the neurotransmitter for all preganglionic neurons?
Ach
What is the neurotransmitter for all post-ganglionic neurons?
NE
(except, the sympathetic ganglion neurons that innervate sweat glands –> Ach via mAChR)
Where are sympathetic fibers for the head + neck found?
Intermediolateral cell column
The baroreceptor reflex is found where?
Rostral ventrolateral medulla
Where do the sympatheitcs for the head synapse in?
Superior Cervical Ganglion
What are the parasympathetic GVEfferent CN’s?
3,7,9,10
Endinger Westphal nucleus = in between 2 + 3
Superior salvatory nucleus =
Inferior salivatory nucleus =
Dorsal nucleus of vagus =
3 –> ciliary ganglion
7 –> sphenopalatine + mandibular glands
9 –> otic ganglion –> parotid glands
10 –> synapse at various viscera
Which CN (2/3) is afferent/efferent.
2 = afferent
3 = efferent (has to be active for light to pass and pupil to constrict)
What happens if you have a lesion in CN 2 Left eye?
If you shine light in the opposite eye (R), both pupils will constrict.
(if you shine light in L eye they wont constrict)
What happens if you have a lesion in CN 3 left eye?
Since 3 allows for the constriction, the opposite eye will work, but the ips. eye will not constrict
A central lesion in Horner’s Syndrome (of sympathetics) means that it happened @ the:
LATERAL brainstem/upper cervical spinal cord
Horner syndrome
preganglionic lesions damage:
postganglionic lesions damage:
pre = sympathetic chain
post = superior cervical ganglion/cavernous sinus –>internal carotid artery dissection
central = blue
green = pre
post = red
What does the baroreceptor reflex prevent?
Orthostatic hypertension –> prevents fluctuations of arterial pressure, for example: where you feel faint if you try to stand up too fast
Where are baroreceptors located + what CN’s are associated w/ them?
Mechanoreceptors in:
Carotid sinus = CN 9 (Inc. + dec. of BP)
Aortic arch = CN 10 (only looks at increases in BP)
When we have an increase in BP, where do the baroreceptors send excitatory signals to?
The nucleus soliatrius of the medulla
What is the pathway for the increase in BP baroreceptor reflex?
Baroreceptors notice increase in BP –> Nucleus solitarius of medulla –> Nucleus ambiguous
What are the 2 roles of the nucleus ambiguous?
- Bradycardia (slows down heart)
- Inhibits the rostal ventrolateral medulla (sym.) to lower BP
What happens when we have a decrease in BP (like in standing up/hemmorrhage)?
More blood gets shunted to the brain to prevent syncope (passing out)
How do we evaluate supraventricular tachycardia?
With a carotid massage (which stretches the baroreceptors) to see if the BP goes down
What happens in baroreflex afferent failure?
Flucuating hypertension
What happens in baroreflex efferent failure?
Orthostatic hypotension (drop of BP, like you’re gonna pass out)
Multiple sclerosis is associated with which mictruition reflex?
Spastic
Which micturition defect has lost the control of the anal reflex?
Flaccid
How do you describe spastic micturition disorder?
Bladder Volume = decreased
Intravesicular pressure = Increased
Retention = none early and then problems later on
How would you describe flacid bladder?
Overflow Incontinence + Urinary Retention
No anal reflex
Spastic + uninhibited bladder both have?
Urinary frequency + urinary incontinence,
but spastic has the decreased bladder volume to separate it
An uninhibited bladder has no retention
What is the cause of uninhibited bladder?
A lesion that affects the inhibitory connections of the medial frontal cortex unable to inhibit the pontine mictruition center
What are the 3 types of neurogenic bladder (disturbances in micturition reflex)?
- Uninhibited
- Spastic
- Flaccid
What 2 things must occur in the medial region of the pontine micturition center in order for peeing to occur?
- Excitatory signals are sent to activate the sacral parasympathetic nucleus
- Inhibitory signals are sent to inhibit the Onuf nucleus (sym.)
Bladder lesion locations
What is the primary center for voluntary control of micturition?
Medial frontal cortex –> it inhibits the pontine micturition center
