C14 4-8 Flashcards
Sympathetic vs. Parasympathetic: CNS origin
Sym: Thoracolumbar, Lateral horns of T1-L2
Para: Craniosacral (brain stem nuclei of cranial nerves III, VII, IX, X and sacral region of spinal cord, segments S2-S4.)
Sympathetic: Location of Ganglia
Within a few cm of CNS:
- alongside vertebral column
(sym trunk/vertebral chain/paravertebral ganglia) - anterior to vertebral column
(collateral/prevertebral ganglia). - Also, adrenal medullae
Parasympathetic: Location of Ganglia
Within the visceral organ or close to the organ served Terminal/intramural ganglia.
Sympathetic: General fiber pathways
Sym: Thoracocolumbar/lateral horn –> Ventral root –> Nerve –> Ventral ramus –> White ramus –> sympathetic trunk ganglion –>
4 options:
1. synapse in the same trunk ganglion, exit thru gray ramus, travel on branches of rami to effector
2. Ascend or descend to synapse with another trunk ganglion,
3. Bypass trunk ganglia, enter/form splanchnic nerve, and synapse in a distant collateral ganglion (abdomen/pelvis)
4. Bypass both trunk and collateral ganglia and synapse in the adrenal medullae.
Parasympathetic: General fiber pathways
Para: Craniosacral –> Terminal ganglia –> Effector cell
Sympathetic vs. Parasympathetic: Length of fibers
Sym: Short preganglionic –> long postganglionic Para: long –> short
Sympathetic vs. Parasympathetic: preganglionic axons branches
Sym: more than 20 Para: less than four (i.e. talks to how may postganglionic?)
Sympathetic vs. Parasympathetic: Degree of response
Sym: short preganglionic fibers with extensive branching facilitate the activation of many structures simultaneously (mass activation).
Para: long preganglionic fibers with limited branches result in a local response.
Sympathetic vs. Parasympathetic: Rami communicantes?
Sym: yes, grey and white Para: no
White rami
Short pathway containing preganglionic sympathetic axons.
axons: pass thru anterior root –> nerve –> white Ramus –> nearest sympathetic trunk ganglion
Entry to the sympathetic trunk! Found only in T1-L2 cord segments.
Grey rami
Short pathway containing postganglionic axons that connect ganglia of the sympathetic trunk to spinal nerves.
Departure point from the sympathetic trunk - allow sympathetic output to all parts of body.
Found by every trunk ganglion from cervical to sacral.
- Explain why parasympathetic activation is local and discrete, and sympathetic activation can result in mass activation.
Parasympathetic : long preganglionic fibers with limited branches result in a local response. Sympathetic: short preganglionic fibers with more extensive branching facilitates the activation of many structures simultaneously (mass activation). Also - thru medulla, release NE into blood, everywhere affected.
- Name the four cranial nerves associated with the parasympathetic division.
Oculomotor, facial, glossopharyngeal, vagus
What is the action of the Oculomotor nerve in the parasympathetic division?
Control ciliary and iris/sphincter pupillae muscle.
Pupil constriction, lens shape for focusing.
Pre-gan CB -Accessory occulomotor nuclei/midbrain –> Pre-gan Axon - oculomotor nerve –>
Post-gan CB -Ciliary Ganglia, –>
What is the action of the Facial nerve in the parasympathetic division?
Activate lacrimal and nasal glands, palate, (pharynx).
Pre-gan CB - Lacrimal nuclei/pons –>
Pre-gan Axon - facial nerve –>
Post-gan CB - pterygopalatine ganglia (hay fever).
Activate submandibular and sublingual glands.
Pre-gan CB - Superior salivary nuclei/pons –>
Pre-gan Axon - facial nerve –>
Post-gan CB - Submandibular ganglia.
What is the action of the Glossopharangeal nerve in the parasympathetic division?
Activate the parotid salivary glands.
Pre-gan CB - Inferior salivatory nuclei/pons –>
Pre-gan Axon - glossopharangeal –>
Post-gan CB - otic ganglia
What is the action of the Vagus nerve in the parasympathetic division?
90% of para, Serves heart, lungs, and abdominal viscera.
Dorsal motor nuclei/medulla –>
send branches to cardiac/pulmonary/esophageal plexuses –>
at the esophagus ant/post vagus trunks join together —>
send fibers thru abdominal aortic plexus —>
terminal/intramural ganglia
Where are the cell bodies of parasympathetic postganglionic neurons found?
Terminal/intramural ganglia. Near or in the organ served.
Sacral outflow of parasympathetic?
S2-S4. Preganglionic axons in sacral spinal branch off to form pelvic splanchnic nerves –> synapse with terminal ganglia.
large intestine,
urinary bladder,
ureters,
repro organs.
What does the sympathetic division innverate?
Visceral organs and all visceral structures in the somatic part of the body (i.e. glands/smooth muscle in the soma - sweat, arrector pili)
Where are the lateral horns found?
Gray matter of spinal cord in T-L segments. No lateral horns found in the sacral region!
Sympathetic trunk?
Flank each side of the vertebral column and extend from neck to pelvis.
Consist of sympathetic ganglia and fibers running from one ganglion to another.
Symp fibers only arise from T-L!!!
Sympathetic trunk/paravertebral/chain ganglia vs. collateral/prevertebral ganglia?
Trunk ganglia:
- found in sympathetic trunk,
- 22-23 pairs
- connections for head, neck, thoracic cavity.
- extend from neck to pelvis
Collateral ganglia:
- Found anterior to the vertebral column, close to ab arteries.
- Not paired or segmentally arranged.
- Occur only in abdomen and pelvis - innervate organs below diaphragm.
- Five major: celiac, superior and inferior mesenteric, aorticorenal, renal.
Where do I find the postganglionic axons of cranial nerves III, VII, IX?
Most hitch a ride on the trigeminal nerve.
What ganglia are connected to cranial outflow?
Ciliary, pterygopalantine, submandibular, Otic (and intramural for vagus)
