Neuro Class 2- Structure of SNS & PNS

taylormaloney's version from 2017-01-11 22:21

Section 1

Question Answer
The sympathetic motor function consists of what 3 portions?1- Path from SC to symp trunk ganglia 2- Organization of trunk ganglia 3- Pathways from symp trunk ganglia to visceral effectors
Breakdown of the motor path from SC to symp trunk gangliaPreganglionic neuron bodies in lateral horn of T1 to L2, travel with somatic motor axons, join ant root of ant ramus of spinal nerve, forms white rami communicantes which reach the nearest sympathetic ganglion of trunk.
Where are the sympathetic trunk ganglia located?On each side of vertebral column- 3 in cervical, 11-12 in thoracic, 4-5 in lumbar, 4-5 in sacral and 1 in coccygeal which is the R + L merged into one fused ganglion.
Where are the postganglionic neurons of the sympathetic division located?In the Sympathetic trunk ganglia.
What axons are received bby the postganglionic neurons?Preganglionic axons from thoracic and lumbar segments of SC.
What are the only named cervical ganglia of the sympathetic trunk?Superior, Middle, Inferior.
What is specific to the inferior cervical ganglion?Fused with the first thoracic ganglia in 80 % of cases, forming the Stellate Ganglion.
The postganglionic axons of the superior cervical ganglia innervate..Sweat glands, SMT of eyes, facial BVs, Lacrimal Gl's, Pineal Gl, Nasal Mucosa, Salivary Gl's and the Heart.
The postganglionic axons of the middle and inferior cervical ganglia innervate...Heart, BVs of neck, shoulder, and upper limb.
What is a stellate ganglion block?A blockage of the connection of the stellate ganglion to the rest of the NS.
What is the function of the Stellate Ganglion Block?Dx the cause of pain in face/head/arms, manage pain in these areass caused by nerve injuries or angina that doesn't go away, reduce sweating in face/hands/arms/head, and treat reflex sympathetic dystrophy/symp maintained pain/complex regional pain syndrome.

Section 2

Question Answer
Where are the thoracic ganglia located?Lie anterior to the neck of the corresponding ribs.
What do they receive? What do they innervate?Most preganglionic axons, heart, lungs, bronchi, and other thoracic viscera. As well as the sweat gl's, BVs and arrector pili within the skin.
Where are the lumbar portions of the trunk located? The sacral?L- lies lateral to the corresponding lumbar vertebrae. S- in the pelvic cavity, on the medial sides of the sacral foramina.

Section 3

Question Answer
Postganglionic axons leave the sympathetic ganglia via what four methods?1- Enter spinal nerve. 2- Form cephalic periarticular nerves. 3- Form sympathetic nerves. 4- Form the splanchnic nerves.
Some axons of postganglionic neurons may also leave the sympathetic trunk via what unmyelinated structure?Gray Rami Communicantes.
Which outnumber the other? Gray rami communicantes or white rami communicantes?Gray.
A gray ramus leads to each.... where they provide sympathetic innervation to...One gray ramus to each pair of spinal nerves, supplying symp innervation to visceral effectors in skin. Sweat gl's, SMT in BV's, and arrector pili muscles.

Section 4

Question Answer
What is the name of the preganglionic axons that have ascended to the superior cervical ganglion where they synapse w/ postganglionic neurons?Cephalic Periarticular N's
What pathway do these nerves parallel?The Carotid Artery Pathways.
What do these nerves innervate?In skin of face/head- sweat gl's, SMT of BVs, and arrector pili. In the Head- SMT of the eye, Lacrimal and Salivary Gl's, Pineal Gl, and Nasal Mucosa.

Section 5

Question Answer
What are the sympathetic nerves?Preganglionic neurons that synapse in one or more trunk ganglia that have then left the trunk.
What do the sympathetic nerves provide innervation for?Heart and Lungs.
The preganglionic axons that go on to supply the heart synapse in..Sup, Mid, Inf Cervical Ganglia and Ganglia of T1-T4
After they synapse they go on to form..The cardiac plexus which innervates the heart.
The preganglionic axons that go on to supply the lungs synapse in.. Synapse in the ganglia of T2-T4.
After they synapse they go on to form the..Post ganglionic fibres go on to form the pulmonary plexus.

Section 6

Question Answer
What are the Splanchnic Nerves?Preganglionic axons that do not go on to synapse in the trunk, and instead form nerves which extend to the prevertebral ganglia.
What are the two groups of splanchnic nerves?N's that go to abdominal organs and N's that go to the adrenal medulla.
Greater Splanchnic NFormed by preganglionic axons of T5-T9/T10. Pierces diaphragm and enters the celiac ganglion.
What does the G Splanchnic N supply?BVs of the stomach, spleen, liver, kidneys and small intestine.
Lesser Splanchnic NFormed by preganglionic axons of T10-T11. Pierces diaphragm and enters the aorticorenal and superior mesenteric ganglia.
What does the L Splanchnic N innervate?BVs of the small intestine and proximal colon.
Least (Lowest) Splanchnic NNot always present, formed by preganglionic axons of T12 ganglia or a branch of lesser splanchnic. Pierces diaphragm and enters renal plexus.
What does the Least Splanchnic N innervate?Innervates kidney arterioles and the ureters.
Lumbar Splanchnic NFormed by preganglionic axons of L1-L4, terminates in the inferior mesenteric ganglion.
What does the Lumbar Splanchnic N innervate?Distal colon and rectum, extends through hypogastric plexus to supply BVs pf Distal Colon, rectum, bladder, and genital organs.
Preganglionic axons that pass without synapsing through symp trunk, greater splanchnic n's or celiac ganglion extend to..The Chromaffin cells in the adrenal medulla.
What is the adrenal medulla?Modified sympathetic ganglia.
The chromaffin cells do not...Extend to another organ.
What do they do?Release epinephrine and norepinephrine. (80/20), into the blood stream.
What is the function of those secretions?Intensify sympathetic responses.