Nervous System II: The Autonomic Nervous System Flashcards
Define the ANS.
a system located both in the CNS and PNS that coordinates visceral activities and maintains homeostasis.
Define GVA and GVE
GVA: sensory nerves monitoring change in organs and transmitting that information to the CNS.
GVE: motor nerves providing innervation to S mm, cardiac mm and glands.
NOTE: SK mm is innervated by GSA and GSE since falls under the control of somatic nervous system.
What is an important difference b/n GVE and GSE?
GVE is organized into a two neuron chain.
-Preganglionic fiber start from CNS and synapse on Postganlionic fiber that start in the ganglion and innervate the target.
List and describe the ganglia associated with the GVE fibers.
Lateral (Paravertebral ganglia): paired structures along the vertebral column (the sympathetic trunk)
Collateral (Prevertebral ganglia): structures located anterior to the vertebral column
Terminal Ganglia: located in or near the walls of organs.
NOTE: These are NOT the Dorsal root ganglia, which is afferent (GVA and GSA)-we are focusing on the efferent side.
What are the ganglia associated with the GVE fibers of the sympathetic and parasympathetic division of the ANS?
- Lateral and Collateral-Sympathetic
- Terminal-exclusively parasympathetic
Describe the organization of the sympathetic nervous system.
Origin Site of Synapse Innervation
-Spinal Cord Sympathetic chain Cardiac mm
levels (T1-L2) (paravertebral ganglia) S mm
-Thoracic Prevertebral ganglia Smm &
Splanchnic glands
nerves (T5-T12
-Lumbar splanchnic Prevertebral ganglia Smm & glands
nerves L1, L2
Where are the cell bodies of the preganglionic neurons in the sympathetic nervous system?
T1-L2 levels of the spinal cord (Sympathetic nervous system described as Thoraco-Lumbar in origin).
Describe the organization of the parasympathetic nervous system.
Origin Site of synapse Innervation
-CN III, VII 4 cranial ganglia glands and Smm of head
and IX
-CN X Terminal ganglia pharynx, larynx, thoracic
& abdominal viscera
-Pelvic Terminal ganglia abdominal and pelvic
Splanchnic viscera
nerves S2, 3, 4
What contributes to the cardiac, pulmonary and esophageal plexus?
The sympathetic and parasympathetic fibers to the heart, lungs and esophagus are mixed together to form these plexus.
What type of plexus is the brachial plexus?
It is a somatic plexus but the cardiac, pulmonary and esophageal plexus are visceral plexus.
Where are the cell bodies of the preganglionic neurons in the parasympathetic nervous system?
Cranial and Sacral levels of the spinal cord
Describe the 3 courses of preganglionic fibers entering the sympathetic chain to synapse on postganglionic fibers.
1) The preganglionic fiber (GVE) can exit the spinal cord and synapse on a postganglionic fiber (GVE) at the corresponding spinal cord level within the sympathetic chain.
2) Can exit the spinal cord and synapse @ a higher or lower level within the sympathetic chain
3) Splanchnic nerves: PANAPTO
Differentiate b/n white and grey rami communicans.
White rami communicans carry preganglionic sympathetic fibers (myelinated) from the spinal nerves to the sympathetic ganglia.
Gray rami communicans carry postganglionic sympathetic fibers (non-myelinated) from the sympathetic ganglia to the spinal nerves.
Identify the location of postganglionic neurons in the sympathetic and parasympathetic nervous system?
Check?
Describe the pattern of innervation of the heart.
Parasympathetic nerves MERGE WITH Sympathetic
(Vagus nerve) Nerves(T1-T4)
CARDIAC PLEXUS
Sinoatrial (SA) node
Atriocventricular (AV) node
Bundle of HIS
Right and Left Bundle Branches
(contain Purkinje fibers)
