Lecture 10: Lumbar Plexus and Pain Flashcards
What is the excitatory hormone of the somatic NS, are there ganglia, and what are the axons like?
- Ach
- No ganglia in this pathway
- Axons are thick and myelinated
What is the NT used by pre-ganglionic cell bodies in the sympathetics; how about post-ganglionic?
Pre-ganglionic = Ach
Post-ganglionic = NE
What are the 2 components of the sympathetic trunk?
Paravertebral ganglion + Interganglionic connections
What are the 3 cervical ganglion?
- Superior
- Middle
- inferior
What ganglion is formed by the fusion of the inferior cervical ganglion w/ the ganglion of T1?
- Stellate ganglion
What are the 4 options for pre-synaptic fibers entering the sympathetic trunk?
1) Ascend
2) Descend
3) Synapse at same level
4) Traverse the trunk w/o synapsing and become part of an abdominopelvic splanchnic nerve or for innervation of the suprarenals
What are gray rami communicans; how many spinal nerves?
- All 31 spinal nerves
- Arise as lateral branches
- Carry post-synaptic fibers to body wall and limbs for distribution via spinal nerves
What are the cephalic arterial rami?
- Go to periarterial plexuses of carotid arteries
- Arise from cervical ganglia
- Post-synaptic fibers to head for distribution via periarterial plexuses
What are the 3 primary effects of the parietal branches of sympathetic trunks?
1) Vasomotion
2) Sudomotion - sweating
3) Pilomotion - erector pilae m. = goosebumps
What is the primary contribution to the celiac ganglion?
Greater splanchnic n
What is the primary contribution to the aorticorenal ganglion?
Predominantly lesser splanchnic
What is the primary contribution to the SMG?
Contributions from all
What is the primary contribution to the IMG?
Primarily lumbar
How do abdominopelvic splanchnic nerves enter the diaphragm?
They pierce the muscle
Which fiber type do the cardiopulmonary splanchnic nerves convey and what kind of ganglia do they synapse in?
- Convey POST-synaptic fibers to thoracic viscera
- Synapse in PARA-vertebral ganglia
Which fiber type do the abdominopelvic splanchnic nerves convey and what kind of ganglia do they synapse in?
- Convey PRE-synaptic fibers
- Synapse in PRE-vertebral ganglia
Do the paravertebral ganglia of sympathetic trunks distribute fibers to the abdominopelvic viscera?
NO, everywhere else
*Pre-vertebral ganglia of para-aortic plexus distribute to abdominopelvic viscera
Why is innervation of the suprarenal glands an exception?
Pre-synaptic fibers to the suprarenals will pass through the pre-vertebral ganglia WITHOUT synapsing. The synapse occurs directly on the secretory cells of the medulla which act as postsynaptic neurons.
How are the pre-synaptic neurons of the sympathetics and parasympathetics different?
Sympathetics = short
Parasympathetics = long
What is the dominant outflow of the parasympathetic presynaptic neurons; where does it extend to?
Cranial outflow is dominant (extends to left colic flexure)
Where are the parasympathetic postsynaptic neurons located in the trunk?
- Widely spread and irregularly spaced
- Located in or on effector (intrinsic/enteric ganglia)
- Found in the Musculosa Externa
What are the parasympathetic postsynaptic neurons in the head?
1) Ciliary
2) Otic
3) Pterygopalantine
4) Submandibular
Do the parasympathetics go to body walls or limbs; are they components of spinal nerves?
- Do NOT go to body walls or limbs, except erectile tissue of external genitalia
- Never components of spinal nerves of their peripheral branches, except for initial parts of S2-S4
What is the left colic (splenic) flexure a landmark for?
Where cranial outflow (i.e., Vagus n.) stops and the Sacral outflow (S2-S4) starts
