PNS - CNS Review

made by MJ

What makes up the CNS?

Brain and spinal cord

What are the main components of the PNS?

Cranial and spinal nerves

How many pairs of cranial nerves?

12 pairs

What kind of information is carried in a nucleus of origin for a CN?

Motor function - cell bodies of LMNs

What kind of information is conveyed in a nucleus of termination?

Sensory - cell bodies of 2nd order sensory neurons

Where do cranial nerves exit the skull?

Patent openings - do not change shape

T/F: Cranial nerves are NOT likely to be impinged/encroached upon at the skull exits.

True - openings do not change shape

How many pairs of spinal nerves are there?

31 pairs - 62 total

How are spinal nerves attached to the CNS?

rootlets

What rootlets are associated with motor and efferent functions?

Anterior/ventral

What rootlets are associated with sensory and afferent functions?

Posterior/dorsal

What does a spinal nerve split into?

Anterior/posterior primary rami

What is the difference between rootlets and rami?

Rootlets - not mixed

Rami - mixed

(note M in rami and mixed)

What kind of information does the anterior primary rami carry?

Mixed information (motor AND sensory)

What information is carried through the somatic pathway?

Sensory and motor

What information is carried in visceral pathways?

Sympathetic and parasympathetic

What spinal levels make up the sympathetic NS?

T1-L2

T/F: Both neurons in the sympathetic NS release acetylcholine and are cholinergic.

False - only first neuron releases Ach. Second releases NE, making the pathway adrenergic.

Which neuron of the sympathetic nervous system is short? Long?

Short - pre-ganglionic (Ach)

Long - post-ganglionic (NE)

What nerves carry preganglionic sympathetic fibers?

Sacral splanchnic nerves

What nerves make up the parasympathetic NS?

CN 3/7/9/10

S2-S4

T/F: Both neurons of the parasympathetic pathway release acetylcholine.

True

Which neuron of the parasympathetic pathway is short? Long?

Short - post-ganglionic

Long - pre-ganglionic

Which splanchnic nerves are associated with the parasympathetic nervous system?

Pelvic splanchnic nerves

What special sense is carried in CN 1?

Olfaction/smell

What do the fibers of CN 1 traverse and where do they synapse?

Cribiform plate

Olfactory bulb

T/F: Sacral splanchnic nerves do NOT synapse in the sympathetic trunk.

True

T/F: Information from CN I travels through the thalamus and uses olfactory bulbs and tracts.

False - does NOT travel thru thalamus

Which is the only cranial nerve to deal with vision information?

CN 2

Where is CN 2 integrated?

Occipital lobe (BA 17)

T/F: All fibers in optic tract cross at optic chiasm.

False - not all fibers

What kind of innervation does CN 3 have?

Somatic and parasympathetic

Where do fibers in CN 2 go?

Lateral geniculate body

What muscle is innervated by the trochlear nerve?

Superior oblique

Which nerve is the great sensory nerve of the face?

Trigeminal nerve (CN 5)

What is the function of the superior oblique?

Turn eye down and out

What muscle is innervated by the abducens nerve?

Lateral rectus

Which nerve is the nerve of facial expression and the great motor nerve of the face?

Facial nerve - CN 7

What special sense does the facial nerve carry?

Taste - anterior 2/3 of tongue

What glands are innervated by the facial nerve?

Lacrimal gland

Which is the only CN to carry two special senses?

CN 8 - vestibulocochlear

Where is hearing integrated in CN 8?

Transverse temporal gyrus

Where is equilibrium integrated in CN 8?

Vestibulocerebellum / flocculonodular lobe

What special sense is carried in the glossopharyngeal nerve? (CN 9)

Taste from posterior 1/3 of tongue

What muscle does the glossopharyngeal nerve supply?

Stylopharyngeus

What gland does the glossopharyngeal nerve provide parasympathetic innervation to?

Parotid gland

What is the longest CN?

Vagus nerve

What muscles are supplied by CN 11?

Trapezius and SCM

Which CN is the most important parasympathetic nerve?

Vagus nerve - CN X

T/F: Hypoglossal nerve carries no taste.

True

What muscles are supplied by the hypoglossal nerve (CN 12)?

Tongue muscles

REVIEW CN AND SKULL OPENINGS

!!!!

Where are the cell bodies of upper motor neurons?

in the CNS

What are the two types of UMN?

Pyramidal - vountary

Extrapyramidal - reflex and coordination

Where do UMNs synapse?

anterior horn (RL 7/9)

Where are the CB of LMN?

inside CNS, leave to PNS

Which motor neurons are entirely within the CNS?

Upper motor neurons

How many neurons are in the somatic motor pathway?

2 neurons from cortex to target

How many neurons are in the somatic sensory pathway?

3

What is the result of a UMN lesion?

Systemic issues

What is the result of a LMN lesion?

Local effects, both excitatory and inhibitory

What motor neuron does a subluxation involve?

LMN

What sensory nerves are involved in subluxations?

1st order sensory neurons at IVF

Which somatic sensory neuron passes through the IVF?

1st order