Introduction to the Visceral Nervous System Flashcards
what is the ANS?
-motor portion of the visceral nervous system (=efferent)
-innervates smooth mm, cardiac mm and glands
2 major subdivisions: sympathetic and parasympathetic
describe the general organization of the ANS
-somatic nervous system: includes only 1 cell body (ventral horn)
-ANS includes two cell bodies:
-preganglionic –> CNS
-postganglionic –> PNS
what are the 3 distinct pathways of the SNS?
1) to the body wall (includes limbs and parts of head/neck)
2) to the body cavity cranial to the abdominal diaphragm
3) to the body cavity caudal to the abdominal diaphragm
what are the 3 visceral structures present in the body wall?
1) sweat and sebaceous glands
2) arrector pili muscles
3) vasculature
where can preganglionic cell bodes be found?
T1-L4 spinal cord levels only
describe the preganglionic sympathetic pathway
1) lateral horn through ventral horn
2) ventral root
3) mixed spinal nerve
4) ventral ramus
5) white ramus communicans
6) paravertebral ganglion –> contains postganglionic sympathetic cell bodies
where can postganglionic cell bodies be found?
in the paravertebral ganglia on every vertebral level
what is the sympathetic chain?
the line-up of all the paravertebral ganglia
what can be found attached to every level of every paravertebral column?
1) somatic motor cell bodies in the ventral horn
2) visceral and somatic sensory cell bodies in the DRG
3) postganglionic sympathetic cell bodies in the paravertebral ganglion
4) a gray ramus communicans
5) a connection to the paravertebral ganglion above and below
what can be found in the T1-L4 spinal cord levels?
same as attached to every level with the addition of:
preganglionic sympathetic cell bodies in the lateral horn
a white ramus communicans
what are attached to all paravertebral ganglia from the cranial cervical ganglion to ~T5?
cardiopulmonary spanchnic nerves (C1-T5)
what are attached to all paravertebral ganglia from ~T5-L6?
abdominopelvic spanchnic nerves
what structures are missing caudal to ~L4?
-no lateral horn – no preganglionic sympathetic cell bodies
-no white ramus communicantes
-everything else is there
what axons are found in each portion of the spinal nerve complex?
1) somatic motor
2) somatic sensory
3) post-ganglionic
how does the preganglionic parasympathetic axon travel to the body?
vagus nerve (CN X)
where do CN X and the sympathetic chain separate?
middle cervical ganglion (C5-C6 paravertebral ganglia)
what is visceral pain?
pain includes the damage of visceral structure, which follows the sympathetic pathway from the structure to the spinal nerve and then to the dorsal root ganglion
poorly localized
one cell body, found in the DRG
what is nonpain?
includes sensations such as fullness, bloating and cramping and this follows the parasympathetic pathway to the brain
what is visceral sensory/referred pain?
organs in the body cavity are associated with the same spinal cord levels that body wall structures are associated with –> pain signals get messed with/mixed up
