Cranial Nerves

Question 1

How many pairs of cranial nerves are there?

Answer 1

12

Question 2

What is the name of the first cranial nerve?

Answer 2

Olfactory

Question 3

What is the pathway of the olfactory nerve?

Answer 3

Passes through the cribriform plate and enters the olfactory bulb in the anterior cranial fossa

Question 4

What is the role of the olfactory nerve?

Answer 4

Special sensory (smell)

Question 5

What is the consequence of a fractured cribriform plate?

Answer 5

Olfactory nerve tear causing anosmia

Question 6

What is the name of the second cranial nerve?

Answer 6

Optic

Question 7

What is the pathway of the optic nerve?

Answer 7

Enters via optic canal to join optic chiasma

Question 8

What is the role of the optic nerve?

Answer 8

Special sensory (vision)

Question 9

What are the clinical application of the optic nerve?

Answer 9

Increase CSF pressure causes papilloedema
Right optic nerve section causes right eye blindness
Optic chiasma section causes peripheral vision loss
Right optic tract section causes left temporal and right nasal field blindness

Question 10

What is the name of the third cranial nerve?

Answer 10

Oculomotor

Question 11

What is the pathway of the oculomotor nerve?

Answer 11

Emerges from midbrain

Exits via superior orbital fissure

Question 12

What is the role of the oculomotor nerve?

Answer 12

Somatic motor control of extra ocular muscles and eyelid

Parasympathetic control of pupil constriction and ciliary muscle causing lens accommodation

Question 13

What are the clinical signs of an oculomotor nerve problem?

Answer 13

Ptosis
No pupillary reflex
No lens accommodation
Eyeball abducted and pointing down

Question 14

What is the name of the fourth cranial nerve?

Answer 14

Trochlear

Question 15

What is the pathway of the trochlear nerve?

Answer 15

Emerges from dorsal surface of midbrain

Exits via superior orbital fissure

Question 16

What is the role of the trochlear nerve?

Answer 16

Somatic motor control of superior oblique

Question 17

What are the clinical signs of trochlear nerve problems?

Answer 17

Diplopia

Question 18

What is the name of the fifth cranial nerve?

Answer 18

Trigeminal

Question 19

What are the 3 branches of the trigeminal nerve?

Answer 19

Ophthalmic (V1)
Maxillary (V2)
Mandible (V3)

Question 20

What is the pathway of the ophthalmic nerve?

Answer 20

Emerges from pons, travels through trigeminal ganglion

Exits via superior orbital fissure

Question 21

What is the role of the ophthalmic nerve?

Answer 21

Sensory into from cornea, forehead, scalp, eyelids, nose, mucosa from nasal cavity and sinuses

Question 22

What is the pathway of the maxillary nerve?

Answer 22

Emerges from the pons, travels through the trigeminal ganglion
Exits via the foramen rotundum

Question 23

What is the role of the maxillary nerve?

Answer 23

Sensory info from the maxilla, teeth, TMJ, nose mucosa, maxillary sinuses and palate

Question 24

What is the pathway of the mandibular nerve?

Answer 24

Emerges from the pons, travels through the trigeminal ganglion
Exits via the foramen ovale

Question 25

What is the role of the mandibular nerve?

Answer 25

Sensory info from mandible, teeth, TMJ, mouth mucosa, anterior 2/3rds tongue Somatic motor control of mastication muscles, part of digastric, tensor veli, palatine and tensor tympani

Question 26

What are the clinical signs of a trigeminal nerve problem?

Answer 26

Paralysis of mastication muscles Loss of control of sneezing reflex Loss of sensation in the face Trigeminal neuralgia

Question 27

What is the name of the sixth cranial nerve?

Answer 27

Abducent

Question 28

What is the pathway of the abducent nerve?

Answer 28

Emerges between pons and medulla | Exits via superior orbital fissure

Question 29

What is the role of the abducent nerve?

Answer 29

Somatic motor control of the lateral rectus

Question 30

What is the clinical sign of a abducent nerve problem?

Answer 30

Medial deviation of the affected eye causing diplopia

Question 31

What is the name of the seventh cranial nerve?

Answer 31

Facial

Question 32

What is the pathway of the facial nerve?

Answer 32

Emerges between the pons and medulla | Exits via the internal acoustic meatus, facial canal and stylomastoid process

Question 33

What is the role of the facial nerve?

Answer 33

Somatic motor control of facial expression muscles Parasympathetic innervation od submandibular and sublingual salivary glands Taste from anterior 2/3 of tongue and soft palate Sensory info from external acoustic meatus

Question 34

What is the clinical sign of a facial nerve problem?

Answer 34

Bell's palsy (facial palsy)

Question 35

What is the name of the eight cranial nerve?

Answer 35

Vestibulocochlear

Question 36

What is the pathway of the vestibulocochlear nerve?

Answer 36

Emerges between pons and medulla | Exits via internal acoustic meatus, divides in vestibular and cochlear nerves

Question 37

What is the role of the vestibulocochlear nerve?

Answer 37

Vestibular sensation from semicircular ducts, utricle and saccule Gives sense of position and movement Hearing from spiral organ

Question 38

What are the clinical signs of a vestibulocochlear nerve problem?

Answer 38

Tinnitus Deafness Vertigo Nystagmus

Question 39

What is the name of the ninth cranial nerve?

Answer 39

Glossopharyngeal

Question 40

What is the pathway of the glossopharyngeal nerve?

Answer 40

Emerges from medulla | Exits via jugular foramen

Question 41

What is the role of the glossopharyngeal nerve?

Answer 41

Taste from posterior 1/3 tongue Sensation from carrots body and sinus Cutaneous sensations from middle ear and posterior oral cavity Somatic motor control to stylopharyngeus Parasympathetic innervation of parotid gland

Question 42

What are the clinical signs of a glossopharyngeal nerve problem?

Answer 42

Loss of gag reflex and taste from back of tongue | Jugular foramen syndrome

Question 43

What is the name of the tenth cranial nerve?

Answer 43

Vagus

Question 44

What is the pathway of the vagus nerve?

Answer 44

Emerges from medulla | Exits via jugular foramen then everywhere

Question 45

What is the role of the vagus nerve?

Answer 45

Taste from epiglottis and palate Sensation from auricle, external acoustic meatus Sensory info from pharynx, larynx, trachea, bronchi, heart, oesophagus, stomach, intestine Parasympathetic innervation of bronchi, gut and heart muscles Somatic motor control of pharynx, larynx, palate and oesophagus

Question 46

What are the cancel signs of a vagus nerve problem?

Answer 46

Pharyngeal branch damage causes swallowing difficulty | Laryngeal branch damage causes speech difficulty

Question 47

What is the name of the eleventh cranial nerve?

Answer 47

Accessory

Question 48

What is the pathway of the accessory nerve?

Answer 48

Small cranial and large spinal roots exit via jugular foramen

Question 49

What is the role of the accessory nerve?

Answer 49

Somatic motor control of soft palate, pharynx, larynx, sternocleidomastoid, trapezius

Question 50

What is the clinical sign of an accessory nerve problem?

Answer 50

Weakness in turning head and shrugging shoulder

Question 51

What is the name of the twelfth cranial nerve?

Answer 51

Hypoglossal

Question 52

What is the pathway of the hypoglossal nerve?

Answer 52

Emerges from medulla | Exits through the hypoglossal canal

Question 53

What is the role of the hypoglossal nerve?

Answer 53

Somatic motor control of the tongue muscles

Question 54

What is the clinical signs of a hypoglossal nerve problem?

Answer 54

Vunerable to damage during a tonsillectomy | Paralysis and atrophy of ipsilateral half of tongue, tip deviates towards affected side