Cranial Nerves

Question 1

How many Cranial Nerves (CN) are there?

Answer 1

12

Question 2

Are most CN attached via two roots?

Answer 2

For the most part, no. In contrast the spinal nerves are typically attached by two roots.

Question 3

What is the origin of most CN?

Answer 3

Single attachment from Brainstem or Forebrain

Question 4

Which two CN are attached by two roots?

Answer 4

V and VII

Question 5

T or F: Cranial Nerves contain ganglia

Answer 5

True, they contain motor and sensory ganglia

Question 6

Do all CN contain the same types of fibers?

Answer 6

No, they each contain a different set (GSA, GSE, GVE,GVA, SA, etc.)

Question 7

Do all spinal nerves contain the same types of fibers?

Answer 7

Yes, they are mixed fiber nerves.

Question 8

How are cranial components of the parasympathetic system distributed?

Answer 8

Via CN III, VII, IX, X “The parasympathetic club of cranial nerves”

Question 9

Motor Ganglia are all _______________.

Answer 9

Chain, Collateral, or terminal parasympathetic autonomic ganglia, in cranial nerves they are all terminal ganglia since all motor autonomics are parasympathetic

Question 10

What are the four parasympathetic ganglia of the CN system?

Answer 10

Cilary, Submandibular, Pterygopalatine, Otic

Question 11

What CN is associated with the Ciliary ganglia?

Answer 11

3

Question 12

What CN is associated with the Submandibular Ganglion?

Answer 12

7

Question 13

What CN is associated with the Pterygopalatine ganglion?

Answer 13

7

Question 14

What CN is associated with the Otic ganglion?

Answer 14

9

Question 15

What type of fibers live in the previously described ganglia?

Answer 15

Postganglionic Parasympathetic fibers

Question 16

What cell types does a dorsal root ganglion house (recall from last block)?

Answer 16

Pseudounipolar neurons

Question 17

What CN have associated sensory ganglia?

Answer 17

V, VII, IX, X

Question 18

What sensory ganglia is associated with V? VII? IX? X?

Answer 18

V:Trigeminal ganglion, VII: Geniculate ganglion, IX: Superior and Inf. ganglia, X: Superior and inf. ganglia

Question 19

What four functions do CN and spinal nerves share?

Answer 19

GSE, GVE, GVA, GSA

Question 20

Are special sensory functions unique to cranial nerves?

Answer 20

Yes- Cranial Nerves only (four basic senses)

Question 21

What functions does GSA have?

Answer 21

General somatic afferent, sensory from skin, skeletal muscles, fascia, joint capsules, ligaments, tendons, aponeuroses, periosteum,

Question 22

What functions does GVA have?

Answer 22

Sensory from visceral structures: smooth muscle, cardiac muscle, glands

Question 23

What functions does GVE have?

Answer 23

Parasympathetic motor innervations to smooth muscle, and glands [III,VII,IX,X]

Question 24

What functions does GSE have?

Answer 24

Motor to skeletal muscle, in head derived from somite or mesoderm

Question 25

What functions does BE have?

Answer 25

Motor to skeletal muscles in head and neck derived from branchial (pharyngeal) arch mesoderm

Question 26

What fibers provide sensory information from ectodermally derived structures?

Answer 26

GSA

Question 27

What fibers provide sensory information from endodermally derived structures?

Answer 27

GVA

Question 28

What functions do Special sensory fibers have?

Answer 28

Sensory related to vision, vestibular, and auditory senses, sensory from specialized receptors located in the head which are associated with visceral activity, taste and smell

Question 29

What provides sensory information from the mucosal lining of oral and nasal cavities?

Answer 29

GSA

Question 30

What provides sensory information from the mucosal lining of pharynx, esophagus, larynx, trachea, middle ear?

Answer 30

GVA

Question 31

What nerve innervates structures derived from the 1st branchial arch? 2nd? 3rd? 4th/6th? 5th?

Answer 31

Mandibular (V3), Facial (VII), Glossopharyngeal (IX), Vagus (X), nothing (arch degenerates), respectively

Question 32

What nerve allegedly can be associated with the 6th arch and what does it innervate?

Answer 32

XI : SCM, Trapezius

Question 33

What does the first arch contain?

Answer 33

Muscles of Mastication, Ant. Belly of digastric, Mylohyoid m. , tensor veli palatini m., tensor tympani m.

Question 34

What does the second arch contain?

Answer 34

Muscles of facial expression, Post. belly of digasatric, Stylohyoid m., stapedius m.

Question 35

What does the third arch contain?

Answer 35

Stylopharngeus m.

Question 36

What does the fourth arch contain?

Answer 36

Larynx, Soft Palate, Pharynx

Question 37

What does the sixth arch contain?

Answer 37

SCM, Trapezius

Question 38

In a neurological exam if you were testing movements of the uvula what nerve would you be examining?

Answer 38

Vagus (Inn. of soft palate via muscles of 4th branchial arch)

Question 39

Do nerves develop from these arches?

Answer 39

No, they develop from neural crest cells and grow into the arches.

Question 40

Are tongue muscles and optic muscles developed from branchiomeric mesoderm? What provides sensory innervation to the tongue?

Answer 40

No, they develop from somite mesoderm Facial Nerve (CN7) provides SVA to the anterior two thirds of the tongue

Question 41

Where are the cell bodies of preganglionic parasympathetic fibers in the head?

Answer 41

Brainstem

Question 42

What are the targets parasympathetic fibers in the head?

Answer 42

Smooth Muscle and Glans

Question 43

What does the parasympathetic aspect of VII and IX innervate in the head?

Answer 43

Glands via Submandibular, pterygopalatine, otic ganglia

Question 44

What does the parasympathetic aspect of III innervate in the head?

Answer 44

Constrictor pupillae muscle via ciliary ganglion

Question 45

What two CN are responsible for spitting and crying (salivation/tearing)?

Answer 45

VII, IX

Question 46

What are the targets of sympathetic innervation to the head?

Answer 46

Sweat glands, Dilator pupillae m. , superior tarsal m. (elevates eyelid, nonvoluntarily)

Question 47

Describe Honer’s syndrome.

Answer 47

Sympathetic lesion to head which causes loss of sympathetic innervation to head, lose sweating, eye is drooping, pupil will not dilate

Question 48

How do pre-ganglionic sympathetic fibers reach the head?

Answer 48

Ascend from T1/T2 to superior cervical ganglion

Question 49

How do postganglionic sympathetic fibers reach the head?

Answer 49

Travel perivascularly on carotid arterial system (in contrast to parasympathetics which travel along cranial nerves)

Question 50

Anytime there is a vascular lesion in the head there is risk of \_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 50

Lesions to postganglionic sympathetic fibers

Question 51

Is your President Black? Is Your Lambo Blue?

Answer 51

That would be affirmative

Question 52

Who is the biggest badass ever?

Answer 52

Ya I said it

Question 53

Foramina of the Cribiform Plate

Answer 53

CN1 Olefactory

Question 54

Optic Canal

Answer 54

CN 2 Opthalamic Artery

Question 55

Superior Orbital Fissure

Answer 55

CN3 - Occulomotor CN4- Trochlear CN V1 - Opthalmic Nerve CN6- Abducens Opthalmic Vein