Lecture 26 - Cranial nerve nuclei

Question 1

What are the four major components of the brainstem?

Answer 1

Midbrain, pons, cerebellum, and medulla

Question 2

What CN nuclei are in the midbrain?

Answer 2

CN III and IV

Question 3

What CN nuclei are in the pons?

Answer 3

CN V and VI

Question 4

What CN nuclei are in the medulla?

Answer 4

CN VII, VIII, IX, X, XI, and XII

Question 5

What is the basic function of the brainstem?

Answer 5

Conduit between brain and spinal cord, motor and sensory tracts carried here

Question 6

What dysfunction is caused by CN I lesion?

Answer 6

Dysosmia

Question 7

What dysfunction is caused by CN III lesion?

Answer 7

Anisocoria, miosis, or mydriasis (also SNS lesion)

Question 8

What dysfunction is caused by CN III, VI, and (IV)

Answer 8

Strabismus

Question 9

What dysfunction is caused by CN IX or X?

Answer 9

Dysphagia

Question 10

What nerves are involved in the corneal blink reflex?

Answer 10

CN V1 and VII

Question 11

What is dysosmia?

Answer 11

Any qualitative or distortion of the perception of smell

Question 12

What can cause dysosmia?

Answer 12

Mechanical damage to area, encephalitis in canines, disease of the cribiriform plate

Question 13

What would you do to test for dysosmia?

Answer 13

Ability to find food

Question 14

What is anisocoria?

Answer 14

Unequal sized pupils

Question 15

What is miosis?

Answer 15

Pathological constriction of the pupil

Question 16

What would miosis mean?

Answer 16

Possible disruption of SNS to eye

Question 17

What is mydriasis?

Answer 17

Pathological dilated pupils

Question 18

What could caused mydriasis?

Answer 18

Possible disruption of PNS to eye

Question 19

Where do the optic nerve fibers synapes?

Answer 19

Pretectal area

Question 20

Where do pretectal nerve fibers synapse?

Answer 20

E-W nuclei

Question 21

Where do the E-W nuclei synapse?

Answer 21

Ciliary ganglia

Question 22

Where do ciliary ganglia nerves synapse?

Answer 22

Pupillary sphincter muscle

Question 23

What is the direct light reflex?

Answer 23

Pupils constrict in eye, stimulated by light

Question 24

What is the consensual light reflex?

Answer 24

Pupil contricts in contralateral eye

Question 25

Where do the nerve fibers involved in the pupillary dilation reflex come from?

Answer 25

Posterior hypothalamus synapse at C8 to T1 lateral horn

Question 26

Where do the preganglionic SNS fiber synapse in the PD reflex?

Answer 26

IN superior portion of sympathetic trunk

Question 27

Where do the postganglionic SNS fiber synapse in PD reflex?

Answer 27

Pupillary dilator muscle

Question 28

What is a strabismus?

Answer 28

Two eyes do not line up in the same direction, and do not look at the same object at the same time

Question 29

What strabismus is caused by a lesion of CN III or midbrain?

Answer 29

Ventrolateral strabismus

Question 30

What is the cause of a ventrolateral strabismus?

Answer 30

Dorsal oblique and lateral rectus are unopposed

Question 31

What strabismus is caused by a lesion of IV or midbrain?

Answer 31

Dorsomedial strabismus

Question 32

What is the cause of a dorsomedial strabismus?

Answer 32

Ventral oblique unopposed

Question 33

What strabismus is caused by a lesion of CN IV or rostral midbrain?

Answer 33

Medial strabismus

Question 34

What is the cause of a medial strabismus?

Answer 34

Medial rectus is unopposed

Question 35

What is dysphagia?

Answer 35

Trouble swallowing

Question 36

What can cause dysphagia?

Answer 36

Lesion of the glossopharyngeal and vagus nerve or caudal medulla oblongata

Question 37

How do you test for dysphagia?

Answer 37

Hyoid pinch or cotton swab to back of throat

Question 38

What is the sensory component of the blink reflex?

Answer 38

CN V1

Question 39

What is the motor component of the blink reflex?

Answer 39

CN VII

Question 40

How do you test for a deficit in the blink reflex?

Answer 40

Touching the medial and lateral canthi or eyelid