Unit Two: Autonomic Nervous System Flashcards
Compare the autonomic nervous system with the somatic nervous system.
The ANS innervates visceral effectors. The SNS’s lower motor neurons innervate skeletal muscles.
What two subdivisions is the ANS composed of?
- Parasympathetic. 2. Sympathetic.
What are the two subdivisions of the PNS?
- Autonomic Nervous System. 2. Somatic Nervous System.
What is the somatic nervous system associated with?
Voluntary movements of skeletal muscles. It involves afferent sensory and efferent motor neurons.
What is the autonomic nervous system associated with?
Involuntary actions of smooth muscles, glands, and visceral structures. It involves afferent sensory and efferent motor neurons.
Where are preganglionic sympathetic neuron cell bodies located?
In the lateral horn of the gray matter form T1 to L2.
Where are the cell bodies of preganglionic parasympathetic neurons located?
In the gray matter of the brain stem and the sacral region of the spinal cord (S2-S4).
Which autonomic division has longer preganglionic neurons?
Parasympathetic.
What is an autonomic plexus?
Collections of sympathetic postganglionic axons, parasympathetic preganglionic axons, and visceral sensory axons.
Where does the cardiac plexus innervate?
Heart.
Where does the esophageal plexus innervate?
Lower esophagus.
What are the two major nerves in the parasympathetic division?
- Vagus nerve. 2. Pelvic Splanchnic nerve.
Where does the celiac plexus innervate?
Foregut.
Where does the superior mesenteric plexus innervate?
Midgut.
Where does the inferior mesenteric plexus innervate?
Hindgut.
What plexuses does the vagus nerve innervate? (5)
- Cardiac. 2. Pulmonary. 3. Esophageal. 4. Celiac. 5. Superior mesenteric.
What plexuses do the pelvic splanchnic nerves innervate?
- Inferior mesenteric. 2. Hypogastric.
Where does the Hypogastric plexus innervate?
Pelvic organs.
Where are the pelvic splanchnic nerves located?
S1-S4.
Where is the vagus nerve located?
X.
Where are synapses located in the sympathetic division?
Sympathetic chain ganglia.
What are white rami communicantes made up of? Is it mylenated?
Preganglionic sympathetic axons of T1-L2 spinal nerves. It is mylenated.
What are gray rami communicantes made up of? Is it mylenated?
Postganglionic sympathetic axons from the sympathetic trunk to the spinal cord. They are not mylenated.
Where do the postganglionic neurons exit?
Through the gray ramus communicantes.
Where does the spinal nerve pathway originate?
T1-L2.
Where does the postganglionic sympathetic pathway originate?
T1-T5.
Where does the splanchnic nerve pathway originate?
T5-L2.
Where does the adrenal medulla pathway originate?
T8-T12.
Where does the spinal nerve pathway innervate?
The integument, including arrector pili muscles, sweat glands, and blood vessels.
Where is the greater splanchnic nerve located? What does it innervate?
T5-T9. The celiac ganglion, plexus, and the foregut.
Where is the lumbar splanchnic nerve located? What does it innervate?
L1-L2. Inferior mesenteric ganglion, plexus, hindgut.
Where are the lesser and least splanchnic nerves located? What does they innervate?
T10-11; T12. Superior mesenteric ganglion, plexus, midgut.
Where are the sacral splanchnic nerves located? What does it innervate?
L3-S2. Hypogastric plexus, pelvic organs.
Which division has greater divergence? Why?
Sympathetic. Has longer postganglionic axons.
Does the parasympathetic division have a local response or a vast response?
A local response.
What is referred pain?
Occurs when impulses from certain viscera are perceived as originating not from the organ but in a dermatome of the skin.
What do sympathetic preganglionic neurons release?
Acetylcholine.
What do sympathetic postganglionic neurons release?
Norepinephrine.
What do all pre- and postganglionic neurons in the parasympathetic division release?
Acetylcholine.
What do all pre and postganlionic neurons in the parasympathetic division release?
Acetylcholine.
Which system includes the pelvic splanchnic nerves?
The parasympathetic.
What artery supplies the foregut?
Celiac trunk.
What artery supplies the midgut?
Superior mesenteric artery.
What artery supplies the hindgut?
Inferior mesenteric artery.
What is the name of the gonadal arteries by sex?
Male: Testicular. Female: Ovarian.
