How many cervical spinal nerves are there?
8
Where do the cervical nerves arise from?
First pair comes from the lateral vertebral foramen of atlas
Remaining emerge cranial to corresponding cervical vertebrae
What are the two branches of CSN 2?
Greater auricular nerve
Transverse cervical nerve
What muscle does the accessory cranial nerve innervate?
Trapezius
What is the function of the CNS?
Relays and integrates info received from the periphery of the body
What is the function of the PNS?
Transmit sensory input and motor output to/from CNS from/to periphery of body
What are the organs of the CNS?
Brain and spinal cord
What is the structure of the CNS?
Gray matter (nuclei) White matter (tracts)
What is the structure of the PNS?
Nerves (white matter)
Ganglia (gray matter)
What is a neuron?
Electrical conducting cells
What are the parts of a neuron?
Receiving end: dendrites, relays information towards the cell body
Conducting end: axon, relays information away from the body
What are afferent and efferent neurons?
Afferent: sensory neurons that relay information to the CNS
Efferent: motor neurons from the CNS
What is the difference of a somatic and visceral neuron?
Somatic deals with transfer of information to/from skeletal muscle
Visceral deals with transfer of information to/from involuntary tissue
Interneurons
Provide integration of information between various regions of the CNS
In what location are all nerves mixed?
Spinal nerves
Dorsal root: afferent neurons
Ventral root: efferent neurons
What are the major divisions of the ANS?
Anatomic
Physiological
Pharmacological
What are the physiological components of the ANS?
Sympathetic division
Fight or flight
Increases energy consumption
Parasympathetic division
Rest and digest
Gains and conserves energy
What are the anatomical divisions of the ANS?
Thoracolumbar
Sympathetic division
Pre synaptic fibers exit from T1-L5
Short fibers
Generally synapse with sympathetic gangliaCraniosacral
Parasympathetic division
Pre synaptic fibers are long
Synapse with ganglia in organs that they innervate
What are the pharmacological regions of the ANS?
Adrenergic receptors which release adrenaline
Cholinergic receptors which release acetylcholine
Where are presynaptic cell bodies located in the SNS?
Thoracic and lumbar portion of the spinal cord
What ganglia form the sympathetic trunk?
Presynaptic sympathetic nervous system ganglia
What makes up paravertebral ganglia?
Post-synaptic sympathetic cell bodies located on either side of vertebral bodies
Axons of pre-SNS neurons may synapse with post-SNS cell bodies in:
Ganglia of paravertebral chain
Ganglia located in cervical chain
Pre-vertebral ganglia
What are the three ganglia within the cervical region?
Cervicothoracic ganglia
Middle cervical ganglia
Cranial cervical ganglia
Where are the pre-vertebral ganglia and which ganglia make up this region?
Caudal to the diaphragm
Celiac ganglion
Cranial mesenteric ganglion
Caudal mesenteric ganglion
What axons are the splanchnic nerves made from and where do they not synapse with?
Pre-SNS axons
Paravertebral chain
What are hypogastric nerves made of and where do they innervate?
Post-SNS axons
Innervate viscera from the pelvic cavity
Where are pre-synaptic cell bodies of PSNS located?
Brain nuclei and sacral regions of spinal cord
Where are post synaptic PSNS ganglia found?
Within the viscera of the organ they serve
Ansa subclavia
This is a loop formed by the division of the sympathetic trunk around the subclavian artery
Where do SNS and PSNS fibers share the same sheath?
Vagosympathetic trunk
These fibers don’t synapse
The nerves travel in opposite directions
SNS fibers travel cranially and PSNS fibers travel caudally
Where are the right and left recurrent laryngeal nerves found?
Left recurrent laryngeal nerve is found curving around the ligamentum arteriosum and the aortic arch
Right recurrent laryngeal nerve is foundcurving around the right subclavian artery
Phrenic nerves
Supply somatic motor innervation to the diaphragm
Mixed nerves
