Lecture 12: Autonomic Nervous System Flashcards
What actions are controlled by the autonomic nervous system?
Involuntary actions
Where is the autonomic nervous system located in the body
CNS (brain and spinal cord) and PNS
Is the autonomic nervous system afferent or efferent?
Efferent
2 subdivisions of the autonomic nervous system
Sympathetic and parasympathetic
What does the parasympathetic system regulate?
Body homeostasis (rest and digest)
What does the sympathetic system regulate?
Fight, Fright, or flight
What are the parasympathetic and the sympathetic systems anatogonistic of one another?
The sympathetic requires energy while the parasympathetic conserves energy.
Similarity between the parasympathetic and sympathetic systems: Embryonic origin of ganglia
Neural crest
What is another similarity between the sympathetic and parasympathetic systems
They both use a 2 neuron pathway with a preganglionic nerve fiber in the CNS and a postganglionic fiber in the PNS
What does the sympathetic system innervate
Sweat glands, arrector pili muscles, abd blood vessels
What does the parasympathetic system innervate
Visceral organs
The are the two afferent components of a spinal nerve
Somatic and Visceral afferent components
Role of Somatic afferent fibers?
Sense pain, temperature, propriocception, and touch (In other words senses stimuli outside the body)
Role of Visceral afferent fibers?
Senses pain and pressure from visceral organs (sense stimuli within the body)
Which localizes pain better, visceral or somatic afferent fibers?
somatic
What are the two efferent components of a spinal nerve?
Somatic and Visceral efferent components
Role of Somatic efferent fibers?
Innervate skeletal muscle
Role of Visceral efferent fibers
These are all autonomic fibers- target visceral organs, blood vessels, sweat glands, smooth muscle, and cardiac muscle
Describe the 2 neuron system in the autonomic nervous system
The preganglionic nerve fiber originates in the CNS and extends out to the PNS to synapse with the Postganglionic nerve fiber, which is always located in the PNS Which then propagates the synapse to the target organ
Where are the cell bodies of the preganglionic fibers ALWAYS located in the sympathetic nervous system
Lateral horn of the spinal cord
What spinal cord levels contain the lateral horn?
T1-L2(3)
What are the spinal cord levels for the preganglionic sympathetic nerve fibers
T1-L2(3)
Is the sympathetic trunk (or paravertebral ganglia) considered post or preganglionic fibers?
Postganglionic because it is not in the brain/spinal cord it is located in the periphery
Where does the sympathetic trunk extend
From the skull to coccyx
Location of the sympathetic trunk
Paravertebral in location (next to the vertebral column)
How many cervical, thoracic, lumbar, and sacral ganglia in the sympathetic chain?
3 cervical
11 thoracic
4 lumbar
4 sacral
Ganglion impar
When 2 sides of the trunks on the sympathetic chain unite as one final ganglia in the coccygeal region
Where are prevertebral ganglia located
Im front of the vertebral column and cemented on aorta
What do prevertebral fibers innervate?
Unpaired visceral arteries
What are the different ganglia associated with the prevertebral ganglia
Celical ganglia (pair), aorticorenal ganglia, superior mesenteric ganglia, and inferior mesenteric ganglia
Role of white rami communicantes
Brings fibers into the symapthetic trunk from spinal nerve
How many pairs of white rams communicantes are there?
14 (From T1-L2)