Final Exam: Unit VII-- Intro, Visceral Afferent, Parasympathetics, Autonomic Plexuses Flashcards
T/F. It is more accurate to think of the sympathetic and parasympathetic systems working in concert with one another to maintain homeostasis and optimal functioning.
True
T/F. There are many more NT than just parasympathetics being cholinergic and sympathetics being adrenergic. And it is safe to assume there is more variability with postganglionic parasympathetics.
True
What is the visceral nervous system concerned with?
the internal env. of the body:
- secretory glands (endocrine and exocrine)
- organs of thoracic and abdominopelvic cavities
- vasculature
Where are cell bodies located for visceral afferents?
posterior root ganglia(aka DRG) or relevant cranial nerve ganglion (in PNS)
What type of neurons are visceral afferents?
unipolar/ pseudounipolar neurons (“appear to have one axon come off body”)
How do the central processes (axons) of visceral afferent enter the cord?
through posterior root or specific cranial nerve
What do the peripheral processes (dendrites) of visceral afferents carry impulses from? Where are they carrying this info to? Via what?
from–> viscera
to–> cell bodies
via–> autonomic ganglia, plexus, or somatic nerves w/o synapse
T/F. We will use the terms visceral and autonomic interchangeably
True
Where are cell bodies located for Sympathetic afferents? What may they travel through?
cell bodies in spinal ganglia (aka DRG, or post. root ganglion) of T1-L2/L3
may travel through sympathetic trunk and to spinal ganglia by passing through white ramus communicans
Where are the cell bodies located for Parasympathetic afferents? how do they travel?
cell bodies in DRG of S2,3,4 or cranial ganglion of CN III, VII, IX, X
travel in spinal nerves or cranial nerves
What are the three sensitivities of receptors that visceral afferents are associated with?
- pressure
- chemical concs. (CO2 and O2)
- muscle stretching (esp. smooth ms in GI)
What cranial nerves and spinal nerves parasympathetic pre-ganglionic fibers carried in?
CNs III, VII, IX, X
sacral spinal nerves S2,3,4
Where to preganglionic parasympathetic neurons typically synapse? What do they release?
synapse on post-ganglionic neurons in peripheral ganglia
are “Cholinergic”–> release ACh
Postganglionic Parasympathetic fibers extend to effector organs to do what four things?
1, decrease cardiac output
- constrict the bronchial tree
- constrict the pupils
- stimulate peristalsis
In general, what will CN III, VII, and IX supply?
parasympathetic structures in the head (smooth muscle and glands)
In general, what will CN X supply?
cardiac, respiratory, and digestive structures in the neck, thorax, and abdomen
(“thoracic and abd. cavities”)
In general, what will S2, S3, S4 parasympathetic fibers supply?
distal parts of digestive system and urogenital systems
“pelvic cavity”
Where are the pre-ganglionic parasympathetic cell bodies located that are carried in the Oculomotor nerve? Where is that located?
Accessory oculomotor nucleus (aka Edinger-Westphal Nucleus); located in the periaqueductal gray
Describe the path of the preganglionic parasympathetic fibers traveling with CN III. Where do they synapse?
follow oculomotor nerve into orbit and synapse in ciliary ganglion
How are the postganglionic parasympathetic axons carried in CN III? What do they supply?
carried in short ciliary nerves–> enter eyeball and supply two muscles:
- Ciliary muscle
- Sphincter pupillae
What are the two muscles supplied by the parasympathetic fibers carried in the Oculomotor nerve and what are their actions?
- Ciliary muscle–> it contracts and it makes lens more convex to focus on closer objects
- Sphincter pupillae–> it contracts and decreases the size of the pupil (constricts pupil)
Where are the cell bodies of preganglionic parasympathetic fibers carried with CN VII located?
superior salivary nucleus
How do the preganglionic parasympathetic fibers exit the CNS that are carried with CN VII? What branches of the Facial nerve are they carried in?
in the intermediate nerve –> carried in two branches of the facial nerve:
1. Greater Petrosal Nerve
2. Chorda Tympani
(both come off w/in facial canal)
Where does the Greater Petrosal Nerve leave the facial nerve? What direction are these preganglionic parasym. fibers carried and what are they carried through?
leave at geniculate ganglion–> carried anteriorward –> through hiatus for the greater petrosal nerve
After the pregang. parasym. fibers carried in the Greater Petrosal Nerve travel through the hiatus for the greater petrosal nerve, how does it re-enter the temporal bone and then where does it travel?
re-enters temporal bone through the petrous part through the foramen lacerum–> travels in pterygoid canal–> then synapses in pterygopalatine ganglion
Where do the pregang. parasym. fibers carried in the Greater Petrosal Nerve synapse?
(branch of CN VII)
synapse in pterygopalatine ganglion
Where are the postganglionic parasympathetic fibers carried in the Greater Petrosal Nerve distributed in and to?
distributed in the lacrimal and other nerves to reach the lacrimal, nasal, palatine, and pharyngeal glands
What are the pregang. parasym. fibers carried through in the Chorda Tympani (branch of CN VII) and how do they leave the temporal bone?
carried through the tympanic cavity–> leaves temporal bone through the pterygotympanic fissure
What will the Chorda Tympani branch of CN VII carrying pregang. parasym. fibers combine with after it leaves the pterygotympanic fissure? What do the pregang. fibers then do?
combines with lingual nerve (branch of V3) —> then leave lingual nerve to reach the submandibular ganglion
Where do the pregang. parasym. fibers carried in the Chorda Tympani synapse? Where are the postgang. parasym. fibers then travel to?
in the submandibular ganglion–> postgang. parasym. then travel to submandibular and sublingual glands
submandibular gland–> fibers to glands in mucous membranes of oral cavity and lingual glands on anterior part of tongue
Where are the cell bodies of pregang. parasym. fibers carried in CN IX located? What branch of CN IX are they carried in? What ganglion do they eventually synapse on?
inferior salivary nucleus; carried in Tympanic Nerve (eventually turns into/renamed to Lesser Petrosal Nerve)–> synapse on otic ganglion
Where does the Tympanic nerve carrying pregang. parasym. fibers come off of CN IX? Where are these fibers carried through and therefore into?
come off of CN IX at the inferior ganglion–> carried through tympanic canaliculus –> into tympanic cavity
Once the Tympanic Nerve carrying pregang. parasym. fibers are in the tympanic cavity, what do they receive? What does this form? How do the pregang. parasym. travel?
receives postgang. symp. fibers from superior cervical ganglion–> and forms tympanic plexus
but the pregang. parasym. pass THROUGH the tympanic plexus and reform as Lesser Petrosal Nerve
Once the pregang. parasym. fibers are in the tympanic cavity (and have pregang. symp. joining them), what do they travel through and reform as? What do these reformed fibers travel through and synapse on?
pass THROUGH the tympanic plexus–> and reform as Lesser Petrosal Nerve–> then travels through lesser petrosal canal to otic ganglion
What structures are the postgang. parasym. traveling from the otic ganglion carried to? How do they get to these two structures? (pregang. parasym. were carried with CN IX)
parotid gland –> via Auricolutemporal Nerve (branch of V3)
posterior lingual gland –> via lingual branches of CN IX
What branch are other visceral afferents parasympathetic fibers carried in of the Glossopharyngeal nerve? From where?
carried in carotid branch–> from:
- baroreceptors in carotid sinus
- chemoreceptors in carotid body
Where are the cell bodies of preganglionic parasym. fibers carried in the Vagus nerve located?
in the posterior (dorsal) nucleus of the vagus
How do the pregang. parasym. fibers carried in CN X travel? What do they ultimately supply?
fibers descend in Vagus nerve; ultimately supply smooth muscle of: - bronchial tree - digestive tract - gall bladder and bile ducts - myocardium and - pancreas - liver - spleen
Where are the postganglionic parasym. cells located that are ass. with CN X? List the three places.
located in organs supplied or blood vessels that supply the organs
- myocardium
- Submucosal plexus (Meissner’s Plexus)
- Myenteric plexus (Auerbach’s Plexus)
How are the pregang. parasym. fibers ass. with the Vagus nerve carried to the heart? Where do they synapse?
in Superior and Inferior Cardiac Nerves –> synapse in cardiac plexus at base of heart and wall of heart
Where are the postgang. parasympathetic fibers ass. with CN X that synapses in the cardiac plexus carried to?
- sinoatrial node (SA node/pacemaker)
- atrioventricular node (AV node)
- atrioventricular bundle–> to reach subendocardial branches (Purkinje Fibers)
What effect with the parasympathetic impulses have on the myocardium? What about the coronary arteries?
inhibit myocardium
CONSTRICT the coronary arteries
How are the pregang. parasym. fibers ass. with CN X carried to the lungs? Where do they synapse?
in anterior and posterior bronchial branches –> synapse in pulmonary plexuses around bronchial tree
After synapsing in the pulmonary plexus, what will the postgang. parasym. fibers ass. with Vagus nerve reach? What effect will this have on these two structures?
bronchial musculature –> constrict bronchial tree
bronchial glands –> increase secretion
When considering asthmatics, what is occurring and what does an inhaler do for an individual with asthma?
asthma–> bronchial tree constricts and glandular secretion is increased
inhaler has meds–> that mimic sympathetic innervation (dilate bronchial tree and decrease secretion)
How are the pregang. parasym. fibers ass. with the Vagus nerve carried to the esophagus? Where do they synapse? What will the postgang. fibers supply?
in Recurrent Laryngeal Nerves and the Anterior and Posterior esophageal branches
–> synapse in wall of esophagus
postgang.–> supply smooth ms fibers of esophagus