Reflexes and Cranial Nerves

Question 1

Biceps

Answer 1

C 5,6 “pick up sticks”, C5 nerve root

Question 2

Triceps

Answer 2

C 7,8 “lay them straight”. C7 nerve root

Question 3

Patella

Answer 3

L 3,4 “kick the door”. L4 nerve root

Question 4

Achilles

Answer 4

S 1,2 “lay them straight”. S1 nerve root

Question 5

Cremaster

Answer 5

L 1, 2 “testicles move”

Question 6

Anal wink reflex

Answer 6

S 3,4 “winks galore”

Question 7

What is the moro reflex?

Answer 7

“hang on for life” reflex-abduct or extend arms when startled, then draw together

Question 8

What is the rooting reflex?

Answer 8

movement of head toward one side of cheek or mouth when stroked (nipple seeking)

Question 9

sucking reflex?

Answer 9

sucking response when roof of mouth is touched

Question 10

Palmar reflex?

Answer 10

curling of fingers when palm is stroked

Question 11

Plantar reflex?

Answer 11

dorsiflexion of large toe and fanning of other toes with plantar stimulation. Babinski sign-presence of refelx in adult-may signify UMN lesion.

Question 12

Galant reflex?

Answer 12

stroking along one side of spine while newborn is in ventral suspension (face down) causes lateral flexion of lower body toward stimulated site

Question 13

CN I
Nerve?
Function?
Type?
Mnemonic?

Answer 13

Olfactory
Smell
Sensory

Question 14

CN II
Nerve?
Function?
Type?
Mnemonic?

Answer 14

Optic
Sight
Sensory

Question 15

CN III
Nerve?
Function?
Type?
Mnemonic?

Answer 15

Oculomotor
Eye movement (SR, IR, MR, IO), pupillary constriction, accomodation, eyelid opening
Motor

Question 16

CN IV
Nerve?
Function?
Type?
Mnemonic?

Answer 16

Trochlear
Eye movement
Motor

Question 17

CN V
Nerve?
Function?
Type?
Mnemonic?

Answer 17

Trigeminal
Mastication, facial sensation (ophthalmic, maxillary, mandibular divisions), somatosensation from anterior 2/3 tongue
Sensory and Motor

Question 18

CN VI
Nerve?
Function?
Type?
Mnemonic?

Answer 18

Abducens
Eye movement
Motor

Question 19

CN VII
Nerve?
Function?
Type?
Mnemonic?

Answer 19

Facial
Facial movement, taste from anterior 2/3 of tongue, lacrimation, salivation, eyelid closing, stapedius muscle in ear
Both

Question 20

CN VIII
Nerve?
Function?
Type?
Mnemonic?

Answer 20

Vestibulocochlear
Hearing, balance
Sensory

Question 21

CN IX
Nerve?
Function?
Type?
Mnemonic?

Answer 21

Taste and somatosensation from posterior 1/3 of tongue, swallowing, salivation, monitoring carotid body and sinus chemo- and baroreceptors, and stylopharyngeus

Question 22

CN X
Nerve?
Function?
Type?
Mnemonic?

Answer 22

Vagus
Taste from epiglottic region, swallowing, soft palate elevation, midline uvula, talking, coughing, thoracoabdominal viscera
Both

Question 23

CN XI
Nerve?
Function?
Type?
Mnemonic?

Answer 23

Accessory
Head turning, shoulder shrugging
Motor

Question 24

CN XII
Nerve?
Function?
Type?
Mnemonic?

Answer 24

Hypoglossal
Tongue movement
Motor

Question 25

CN V motor lesion

Answer 25

Jaw deviates toward side of lesion due to unopposed force from the opposite pterygoid muscle

Question 26

CN X lesion

Answer 26

Uvula deviates away from side of lesion. Weak side collapses and uvula points away

Question 27

CN XI lesion

Answer 27

Weakness turning head to contralateral side of lesion (SCM). Shoulder droop on side of lesion (trapezius). The left SCM contracts to help turn the head to the right

Question 28

CN XII lesion (LMN)

Answer 28

Tongue deviates toward side of lesion ("lick your wounds") due to weakened tongue muscles on the affected side.

Question 29

What passes through the cavernous sinus?

Answer 29

CN III, IV, V1 (ophthalmic), V2 (Maxillary), CN VI, and postganglionic sympathetic fibers en route to the orbit all pass through the cavernous sinus. Cavernous portion of internal carotid is also here

Question 30

What is cavernous sinus syndrome?

Answer 30

It is due to mass effect, fistula, thrombosis-ophthalmoplegia and decreased corneal and maxillary sensation with normal visual acuity. CN VI commonly affected.

Question 31

What is the canvernous sinus?

Answer 31

Collection of venous sinuses on either side of the pituitary