Lecture 15: ANS Pain Flashcards
How many neurons are in the pain system?
Two neurons
Where is the preganglionic and post-ganglionic neuron in the pain system found?
The preganglionic neuron is in the CNS and the axon is in the PNS
The postganglionic neuron is in the peripheral nervous system
What is the autonomic NS responsible for innervating?
Visceral tissues:
Internal organs
Smooth muscles
Glands of skin
What are the two divisions of the autonomic nervous system?
Sympathetic and Parasympathetic
What can the sympathetic and Parasympathetic system be likened to?
The on and off
How does the sympathetic system affect the lungs, heart and gut?
It increases lung capacity and HR and turns of the gut
How does the parasympathetic nervous system affect the lungs, heart and gut?
It decreases HR and lung capacity and turns on gut
What is the sensory portion of the autonomic nervous system?
Visceral afferent fibres that sense pain only
How many neurons are in the visceral afferent pathway?
One neuron
What pathway is used in the somatic motor system?
Corticospinal tract and corticobulbar tract
Where in the spinal cord is the motor neuron in the somatic motor system?
In the ventral horn, travels to the ventral root and to each spinal nerve
How many neurons are in the autonomic motor pathway?
Two neurons
How many neurons are in the autonomic motor pathway?
Two neurons
What are the two neurons in the autonomic motor pathway?
Preganglionic and post ganglionic neurons
Where is the postganglionic neuron of the autonomic motor system located?
In the PNS in an autonomic ganglion
Where does the postganglionic neuron of the autonomic motor system go to?
Visceral targets:
- Cardiac muscle
- Glands
- Smooth muscle
What is the general pathway of preganglionic neuron in the motor autonomic pathway?
Preganglionic neurons go through the ventral root and extend axons out to join with the spinal nerve to find the autonomic ganglion
What has visceral afferents?
All organs
What sensations do somatic afferents sense?
Many sensations - Hot, cold, pressure, itch, light touch, dull pain, sharp pain
What sensations do visceral afferents sense?
Visceral afferents only sense pain
How can the pain by visceral afferents be described?
Vague, dull, ill localized and poorly focused
What is another name for Sympathetic motor outflow?
Thoracolumbar outflow
What is another name for Parasympathetic outflow?
Craniosacral outflow
What is another name for Thoracolumbar outflow?
Sympathetic