Final Exam: Unit VII-- Intro, Visceral Afferent, Parasympathetics, Autonomic Plexuses Flashcards
(115 cards)
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