A
Afferent nerves are...
Sensory
What is the function of the parasympathetic division?
Conserves energy:
Lowers blood pressure, decreases heart rate, constricts airways and pupils, promotes peristalsis and glandular secretion of digestive tract
Dorsal root ganglion contain...
sensory neuron cell bodies
Sympathetic trunk ganglion contain...
motor neuron cell bodies
How many cranial and spinal nerves are there?
12 cranial nerve pairs
31 spinal nerve pairs
Which neurotransmitter is released by the parasympathetic division?
Acetylcholine
What are the four nerve codes?
GVA (general visceral afferent)
GSA (general somatic afferent)
GVE (general visceral efferent)
GSE (general somatic efferent)
Which division of the PNS is comprised of a chain of two neurons?
Autonomic Nervous System (presynaptic and postsynaptic)
Somatic Nervous System has 1 motor neuron that extends from CNS to skeletal muscle
What are the nerve codes for the phrenic nerve?
Somatic motor (GSE) to diaphragm
Somatic sensory (GSA) from diaphragm, mediastinal pleura, and parietal pericardium
What are the nerve codes for the Vagus nerve?
Visceral motor (GVE), Visceral sensory (GVA) fibers to/from thoracic and abdominal viscera
Which division of the autonomic nervous system has long postsynaptic fibers?
Sympathetic
(Parasympathetic are short for localized effect)
What is a splanchnic nerve?
Branch of the sympathetic trunk involved with innervating thoracic and abdominopelvic viscera
Name the thoracic splanchnic nerves
Lesser splanchnic T10 & T11
Least splanchnic T12
What is a funcitonal difference of presynaptic and postynaptic fibers?
Presynaptic fibers are relatively short, postsynaptic fibers are relatively long
What is the nerve code for the right and left recurrent laryngeal nerve?
GSE to muscles of larynx
Compare craniosacral outflow to thoracolumbar outflow
Craniosacral- parasympathetic, brain stem cranial nerves, S2-S4
Thoracolumbar- sympathetic, T1-L2
White rami contains...
Presynaptic sympathetic fibers traveling to sympathetic trunk, only in thoracolumbar region
Which splanchnic nerves are sympathetic vs. parasympathetic?
Most splanchnic nerves are sympathetic (cardiopulmonary, abdominopelvic), but the pelvic splanchnic nerves are parasympathetic
Unmyelinated fibers are associated with
Unmyelinated fibers are gray rami and are postsynaptic sympathetic fibers traveling to peripheral structures. They occur on all trunk ganglia because blood vessels, arrector pili, and sweat glands must be innervated in all body segments.
What comes together to form the spinal nerve proper?
Dorsal root and ventral root
Where do you find presynaptic neurons?
Intermediolateral Cell Columns (IMLs) of spinal cord
Where do you find postsynaptic neurons?
Paravertebral and Prevertebral ganglia
Referred pain occurs because...
2 sensory inputs into spinal cord at the same level = convergence of somatic and visceral sensory neurons (GSA + GVA)
Name the four sympathetic pathways:
1. Ascend and then synapse (innervation of head and upper limb)
2. Synapse at level of entry (innervation of middle trunk, thoracic cavity viscera)
3. Descend then synapse (innervation of lower limb)
4. Pass through sympathetic trunk without synapsing (innervation of abdominopelvic visera)
What is the difference between multipolar and unipolar neurons and which one is more abundant?
Multipolar = MOTOR
Has many dendrites and a single axon, more abundant
Unipolar = SENSORY
No dendrites and one axon with peripheral and central processes