neurology review

Question 1

name three differences between UMN and LMN

Answer 1

1. UMN are in the head and spinal cord, LMN are in the rest of the body
2. UMN= contralateral symptoms, LMN= ipsilateral symptoms
3. UMN are myelinated by oligodendrocytes and can myelinated multiple nerve axons; LMN are myelinated by Schwann cells and can only myeline one single nerve axon

Question 2

name three difference between the corticobulbar tracts and the corticospinal tracts

Answer 2

1. CB contains the CN’s, CS contains spinal nerves
2. CB is shorter, CS is longer
3. CS cross in the medulla to the contralateral side, CB have bilateral projections for all CN’s except 7 and 12.

Question 3

what is the difference between motor and sensory

Answer 3

motor is efferent (brain to body)
sensory is afferent (body to brain)

Question 4

why is CN 5 important?

Answer 4

provides sensory and motor to the velum

sensory to the face and lips

motor and sensory to the jaw

sensory to the tongue

Question 5

why is CN 7 important?

Answer 5

provides motor to the face and taste to anterior 2/3 of the tongue

Question 6

why is CN 9 important?

Answer 6

provides sensory and motor to the pharynx

sensory to the velum

and taste to posterior 1/3 of the tongue

Question 7

why is CN 10 important?

Answer 7

provides motor to the pharynx

motor and sensory to the larynx

and motor to the velum

Question 8

what is CN 12 important?

Answer 8

motor to the tongue

Question 9

what are the exceptions to bilateral innervation?

Answer 9

all CN are bilaterally innervated except for 7 and 12

Question 10

what is the purpose of the superior laryngeal nerve

Answer 10

external branch: provides motor to cricothyroid

internal: sensory to area above vocal folds

Question 11

what is the purpose of the recurrent laryngeal nerve?

Answer 11

motor to vocal folds and sensory to below the vocal folds