Autonomic Nervous System (ANS) Flashcards
What do the sensory neurons convey info from?
from the interoceptors such as chemoreceptors and mechanoreceptors to the integrating center in the CNS
Which type of muscle do the motor units not relay impulse to (ANS)?
Skeletal
What’s the difference between ANS and SNS regarding neuron pathways?
ANS has two motor neurons: preganglionic and postganglionic. Whereas SNS, the motor axon goes from the CNS directly to the skeletal muscle.
Explain a preganglionic neuron.
Cell bodies within the CNS (in lateral grey horns (sympathetic…) of spinal cord and in the nuclei of cranial nerves III, VII, IX, X (parasympathetic…)
Myelinated fibers
From CNS to autonomic ganglion
Explain postganglionic neuron.
Within the autonomic ganglion.
Unmyelinated
From ganglion directly to effector.
Does the ANS work with or without conscious control?
Usually without conscious control.
What is the enteric division?
A specialized network of nerves and ganglia in the GI tract (ANS)
Where are the visceral afferent neurons located?
in the dorsal root ganglia of the spinal nerves
Where are the visceral efferent neurons located?
Mainly in the lateral grey bodies with some in the anterior horn.
Where does the synapse between pre and post-ganglion happen?
autonomic ganglia
What are the 3 types of ganglia?
1 - Sympathetic trunk (sympathetic)
2 - Prevertebral ganglion (sympathetic)
3 - Terminal (intramural) ganglion (parasympathetic)
Where is the sympathetic trunk located?
Closely on each side of the vertebral column
Where are the prevertebral (collateral) ganglion found?
Found anterior to the large abdominal arteries.
Like the, 1)celiac ganglion
2) Superior mesenteric ganglia
3) Inferior mesenteric ganglia
Which 2 receive their preganglionic fibers from the thoracolumbar (sympathetic) division?
sympathetic trunk and prevertebral ganglia
T1-T12, L1, L2
Where are the terminal (intramusal) ganglion located?
Very close to or in the visceral effectors (smooth/cardiac muscle/glands/organs)
Where does the terminal (intramusal) ganglion receive their preganglionic fibers?
Directly from the craniosacral (parasympathetic) division of ANS FROM CIII, CVII, CIX, S2-S4
All ganglia receive preganglionic neurons except for…
the greater splanchnic nerve that stimulates the adrenal gland
Craniosacral is (parasympathetic/sympathetic).
Thoracolumbar is (parasympathetic/sympathetic).
Craniosacral - parasympathetic
Thoracolumbar - sympathetic
The spinal segments involved in the sympathetic divisions are?
T1-T12, L1, L2
The preganglionic fibers enter the sympathetic chain via the?
white rami
after synapsing, the postganglionic fibers enter the ventral rami, by way of the (grey/white) rami commissures.
grey
Do all presynaptic (sympathetic) fibers synapse in the sympathetic trunk?
No
What are presynaptic nerves called?
Splanchnic
Where are the splanchnic nerves found?
below diaphragm
