Lecture 7: Autonomic Nervous System Flashcards
Spinal Nerve
Mixed nerve carrying motor, sensory and autonomic signals between spinal cord and the body. Made of 4 types of nerve fibers
Dorsal Root Ganglion
Contains afferent cell bodies
Autonomic Nervous System
Innervates smooth muscle, Cardiac Muscle, Glands. Just GVE, not GVA under this def. 2 Motor neuron system
Sympathetic vs. parasympathetic
Sympathetic is thoracolumbar nerve roots (T1-L2) parasympathetic is craniosacral nerve roots
where are pre-ganglionic somas found
intermediolateral nucleus in column, can be seen as extral bump in gray matter in cord T1-L2
Where do the two neurons synapse
In either the sympathetic chain or pre-vertebral ganglion (celiac, superior mesenteric, inferior mesenteric)
Pathway of nerves passing through sympathetic chain
intermediolateral nucleus –> ventral root –> spinal nerve root –> white ramus communicans –> sympathetic chain ganglion (could synapse here or pass through to different ganglion through sympathetic trunk) –> synapse with post-ganglionic fiber –> axon passes through gray ramus communicans (could exit here or pass through to different ganglion through sympathetic trunk) –> down ramus –> effector
SPlanchnic nerve
Name for pre-ganglionic fiber when it is synapsing in pre-vertebral ganglion
Three pre-vertebral ganglion
celiac ganglion, superior mesenteric ganglion, inferior mesenteric ganglion
Four categories of splanchnic nerves with root values
Greater (T5-T9); Lesser (T10-T11), Least (T12); Lumbar (L1-L2)
Pre-sympathetic root values
Craniosacral Cranio (iii, iv, ix, x) sacral (S2-S4)
Pelvic Splanchnics
S2-S4, innervate large intestines, bladder genitals
Cranial Nerves
Somas in brain or brain-stem but innervate structures all over the body
parasympathetic vs sympathetic axon lengths
Parasympathetic long pre-ganglionic
(synpase near effector), sympathetic short pre-ganglionic
innervation of large intestine
Vagus innervates to left of left colic flexure, pelvic splanchnic nerve innervates to right
