Visceral ANS Flashcards
The nervous system that innervates smooth muscle, cardiac muscle, and glands
It consists of how many neurons
Visceral Autonomic Nervous System
Two neuron system
Where are the cell bodies of the preganglionic and postganglionic neurons of the ANS located? What types of neurons are they? Where do they terminate?
The preganglionic neuronal cell bodies (multicellular) are located in the CNS, grey matter of the spinal chord (Intermediolateral cell column) or Brain stem (Cranial nerve nuclei)
The post ganglionic neuronal cell bodies (multicellular) are located outside the CNS in the autonomic ganglia
The post ganglionic neurons terminate a the visceral target organ (smooth, cardiac, glands)
The Visceral ANS is divided into two divisions, what are they
Sympathetic and Parasympathetic
Where are the preganglionic cell bodies of the sympathetic division of the ANS located?
The grey matter of the lateral horn (thorocumular cell column) of vertebrae T1 through L2
Where are the preganglionic cell bodies of the parasympathetic division of the ANS located?
In craniocacral regions. Preganglionic neurons of the parasympathetic region have cell bodies located on cranial nerves CNIII, CNVII, CNIX, and CNX (3, 7, 9, 10) and regions S 2,3,4 of the sacrum
What is the path of all sympathetic pre ganglionic neurons from cell body to paravertibral ganglion (sympathetic chain ganglion)?
Cell body in grey matter of lateral horn (intermediolateral cell column) the nerve travels out of lateral horn in to ventral rami (root) into the mixed spinal nerve, into the ventral ramus and quickly out of the ventral ramus into the white ramus communicans and into the paravertibral ganglion (sympathetic chain ganglion
The four paths of sympathetic preganglionic neurons after they reach the paravertibral ganglion (sympathetic chain ganglion)
Ascend to a higher paravertibral level and synapse on postganglionic neuron
Descend to lower paravertibral level
Synapse on post ganglionic neuron at the same level
Or transverse through the paravertibral ganglion and into the splanchnic (visceral) nerves to the GI tract and synapse in the Prevertibral (aortic) ganglion
Why are white ramus communicants white? How many are there in the body?
They are myelinated nerves.
14 pairs, 28 total
What is the exception to the preganglionic nerves of the sympathetic division?
The adrenal gland. The preganglionic neurons for the adrenal gland pass through the paravertibral ganglion and go directly to the adrenal medially, releasing acetylcholin onto the adrenal gland cells. The cells then release epinephrine into the blood stream creating a systemic effect.
Where are the postganglionic cell bodies of the sympathetic NS located?
The postganglionic cell bodies are located in the paravertibral ganglia (sympathetic chain ganglia) or prevertibral (pre aortic) ganglia (for the GI tract)
Where are paravertibral ganglia (sympathetic chain ganglia) found along the spinal column? How many per section?
How do the paravertibral ganglia communicate with the spinal nerves?
They are usually segmented (one ganglia per vertebrae) except in the cervical region, there are usually 3 ganglia that supply the 8 cervical spinal nerves.
They communicate through the grey rami communicans (grey because unmeylinated)
31 pairs, 62 total
Myelinated nerves of the white rami communicants are?
Unmyelinated nerves of the grey rami communicants are?
Preganglionic sympathetic
Postganglionic sympathetic
The neurotransmitter released by pre ganglionic sympathetic neurons is? What type of receptors does it act on?
Acetylcholine - nicotinic receptors
The neurotransmitter released by postganglionic sympathetic neurons is? what type of receptors does it act on?
Norepinepherine
- Alpha1 (blood vessel) , alpha 2
- Beta1 (heart), 2 (lungs)
Alpha 1 and Beta 1 - Generally Excitatory
Alpha 2 and Beta 2 - Generally Inhibitory
