FE: Lecture 1 ANS Flashcards
In the CNS what are LMN called?
somatic motor or branchial motor neurons because it projects to muscle
In the CNS what are preganglionic neurons?
autonomic visceral motor neurons or special visceral
What are the preganglionic fibers in the CNS?
they go to smooth, cardiac muscle and glands
- short- sympathetic thoracolumbar
- long- parasympathetic craniosacral
there are not LMN bc they do not project directly to muscle
In the PNS what are the type of motor ganglia neurons?
chain ganglia, collateral ganglia and enteric
What are the post ganglionic fibers in the PNS?
long - sympathetic
short- parasympathetic
What types of neurotransmitters are associated with the two different nervous systems?
acetycholine (nicotinic and muscarine receptors)- parasympathetic
acetylcholine (nicotinic) and norepinepherine (adrenergic)
Do CNS motor nerves project directly or indirectly to organs and glands?
indirectly
- sympathetic motor nerves are in thoracolumbar and project to chain and collateral ganglia (celiac, mesenteric etc.)
- parasympathetic- in craniosacral and go to enteric ganglia in organs
If you were to pull your heart out of your body would it stop beating?
No b/c it it driven by ganglia not CNS
What is the path of the sympathetic nervous system?
- interiomedial nucleus on the lateral horn to sympathetic ganglia
- sympathetic ganglia neurons then project to smooth muscle and glands
Besides cranial nerves where are the other parasympathetic nerves?
sacral cord- start at sacral “interomediolateral nucleus” or preganglionic ganglia to parasympathetic ganglia
usually enteric ganglia from sacral region are within pelvis, bladder, colon, rectum, reproductive system
What cranial nerves contain parasympathetic visceral motor fibers?
- Oculomotor nerve- EW nucleus (midbrain)
- Facial Nerve- Sup. Salivatory nucleus (pons, middle)
- Glossopharyngeal - inf. sal. nucleus (rostral open medulla)
- Vagus- dorsal motor of vagus (cadual open medulla)
If you were attacked late at night at Ruggles what parts of sympathetic nervous system would increase?
HR, cardiac artery diameter, bronchi diameter, pupil diameter, sweat gland activity, piloerector muscles
If you were attacked late at night at Ruggles what parts of parasympathetic nervous system would increase?
skin artery diameter, bladder tone, saliva and mucus secretion, muscle activity in gut
What nerve is Auerbach’s plexus associated with?
vagus nerve- parasympathetic to gut
motor ganglia are in thoracic and abdominal region
What ganglia does EW nucleus go to?
Ciliary on outside of eyeball
What are two functions of ciliary ganglia?
- ciliary muscles- lens accommodation
2. iris muscles- pupil constriction
What two motor ganglia does the superior salivatory nucleus project to (facial nerve)?
- pterygopalatine ganglia- lacrimal glad = tear production
2. submandibular ganglia- sublingual and submandibular glands- saliva production
What motor ganglia does the inferior salivatory nucleus project to?
otic ganglia (inside parotid gland)- salivation
damage leads to dry mouth
What is the main effect of sympathetic and parasympathetic systems?
para- rest and digest, store energy
sym- fight or flight, use energy
How does visceral sensory information enter the CNS?
- sensory receptors in organs send AP to spinal and cranial nerves via visceral sensory ganglia
- they then synapse in nucleus of solitary tract lead to visceral motor reflexes ( start of tract back down)
How does cardiac visceral control work?
- blood pressure increase is detected by receptors (carotid body and baroreceptors)
- this is sent to nucleus of solitary tract by CN 9 -10
- then sends to visceral motor to increase parasympathetic and decrease sympathetic to slow heart rate
What three nerves are responsible for special visceral of taste?
CN 7 anterior 2/3 of tongue
CN 9 posterior 1/3 tongue
CN 10- epiglottis and uvula
What is the tract of taste to frontal cortex?
- CN 7, 9 10 to Solitary nucleus
- solitary nucleus to VPM
- VPM to insula and frontal cortex
What type of afferent fibers go to the solitary nucleus?
mechanical, chemical, thermal, and pain receptors
from solitary nucleus to visceral motor nucleus and reticular nuclei which produces autonomic reflexes
What is main role of hypothalamus?
regulates the state of the ANS, controls reticular nuclei through the hypothalamospinal/ bulbar tract that controls pituitary gland
What parts of cortex control hypothalamus?
cingulate cortex, insula, amygdala
if you see a bear the heart rate increases because of this- Adds fear
What is a syndrome from damage to control centers of ANS?
Horner’s syndrome
main symptoms: 1. ptosis- eye drooping due to paralysis of sympathetic tarsal muscles
- miosis- pupil constriction
- anhydrosis- no water
- enopthalmosis- eyeball falls back into orbit
What causes Horner’s Syndrome?
damaged to sympathetic chain/ collateral ganglia
damage to interiomediolateral damage
damage to hypothalamus or tract
