Lecture 15 - Cranial Nerves

Question 1

collections of axons coming off the brainstem

Answer 1

cranial nerves

Question 2

how many pairs of cranial nerves are there?

Answer 2

12

Question 3

what type of neurons are the cranial nerves?

Answer 3

some pure motor, some pure sensory, others mixed

Question 4

which of the cranial nerves are involved in parasympathetic stimulation?

Answer 4

III, VII, IX, and X

Question 5

cell bodies of sensory neurons live in:

Answer 5

CN ganglia

Question 6

the only cranial nerves that don’t come off the brainstem

Answer 6

I and II

Question 7

cranial nerve I is called the:

Answer 7

olfactory nerve

Question 8

what type of nerve is the olfactory nerve and what is its function?

Answer 8

pure sensory, responsible for sense of smell

Question 9

sensory receptors in the roof of the nasal cavity

Answer 9

olfactory epithelium

Question 10

olfactory nerve filaments supplies the:

Answer 10

olfactory epithelium

Question 11

what is the path that sensory information follows through the olfactory nerve?

Answer 11

olfactory epithelium –> olfactory nerve –> olfactory bulb –> olfactory tract –> primary olfactory cortex

Question 12

where is the primary olfactory cortex located?

Answer 12

the temporal lobe

Question 13

the only sensory system to bypass the thalamus?

Answer 13

olfactory nerve system

Question 14

damage or disease of the olfactory leads to:

Answer 14

hyposmia/anosmia (decreased ability to smell)

Question 15

cranial nerve II is called the:

Answer 15

optic nerve

Question 16

what type of nerve is the optic nerve and what is its function?

Answer 16

pure sensory, vision

Question 17

what is the path that sensory information follows through the optic nerve?

Answer 17

retina –> axons of ganglion cells –> optic nerve –> optic chiasm –> optic tract –> lateral geniculate nucleus –> optic radiations –> primary visual cortex

Question 18

what happens in the optic chiasm?

Answer 18

some sensory information crosses over to the contralateral side of the brain, some sensory information stays on the ipsolateral side

Question 19

the lateral geniculate nucleus is part of the:

Answer 19

thalamus

Question 20

the medial aspect of the occipital lobe on either side of the calcarine sulcus

Answer 20

primary visual cortex

Question 21

how are visual fields projected onto the visual cortex?

Answer 21

in an inverted and reversed fashion

Question 22

damage or disease of the optic nerve leads to:

Answer 22

visual field defects (ex: blindness)

Question 23

cranial nerve III is called the:

Answer 23

oculomotor nerve

Question 24

the oculomotor nerve comes off of the:

Answer 24

Midbrain

Question 25

what type of nerve is the oculomotor nerve?

Answer 25

mixed nerve (somatic motor and parasympathetic)

Question 26

the motor components of the oculomotor nerve control:

Answer 26

the medial rectus, superior rectus, inferior rectus, inferior oblique, and levator palpebrae superioris (all extra-ocular muscles except the lateral rectus and superior oblique)

Question 27

the parasympathetic component of the oculomotor nerve controls:

Answer 27

pupillary constriction and accomodation of the lens

Question 28

damage or disease of the oculomotor nerve leads to:

Answer 28

pupillary dilation (unopposed sympathetics) and ophthalamoplegia (eye movements weakened or paralyzed)

Question 29

cranial nerve IV is called the:

Answer 29

trochlear nerve

Question 30

what type of nerve is the trochlear nerve, and what is its function?

Answer 30

motor nerve, innervates the superior oblique muscle (in the eye)

Question 31

comes off the back of the brainstem (midbrain) and wraps around to reach the superior oblique

Answer 31

trochlear nerve (CN IV)

Question 32

ture or false: isolated damage of the troclear nerve is common

Answer 32

false

Question 33

cranial nerve V is called the:

Answer 33

trigeminal nerve

Question 34

what type of nerve is the trigeminal nerve?

Answer 34

mixed nerve (sensory and motor)

Question 35

CN V has three branches arising from the trigeminal ganglion known as the:

Answer 35

- ophthalmic nerve (V1) - maxillary nerve (V2) - mandibular nerve (V3)

Question 36

what is the function of the ophthalmic nerve (V1)?

Answer 36

receives sensory information from the eye and upper parts of the face

Question 37

what is the function of the maxillary nerve (V2)?

Answer 37

receives sensory information from the cheek

Question 38

what is the function of the mandibular nerve (V3)?

Answer 38

has both sensory and motor (chewing) innervation in the mandible

Question 39

disease of the trigeminal nerve leads to:

Answer 39

trigeminal neuralgia (nerves fire for no reason and causes excruciating pain)

Question 40

supplies sensation to the frontal and ethmoidal paranasal air sinuses, nasal cavity, upper eyelid, side of the nose, forehead, and scalp

Answer 40

ophthalmic nerve (CN V1)

Question 41

enters the floor of the orbit through the inferior orbital fissure

Answer 41

maxillary nerve (CN V2)

Question 42

supplies sensation to the maxillary air sinus, nasal cavity, lower eyelid, skin of cheek, upper lip, and upper teeth/gums

Answer 42

maxillary nerve (CN V2)

Question 43

the largest branch of the trigeminal nerve

Answer 43

mandibular nerve (CN V3)

Question 44

supplies motor commands to the muscles of mastication

Answer 44

mandibular nerve (CN V3)

Question 45

the three main branches of the mandibular nerve (CN V3)

Answer 45

- inferior alveolar nerve - lingual nerve - mental nerve

Question 46

supplies sensation to the mandibular teeth and gums

Answer 46

inferior alveolar nerve

Question 47

supplies sensation to the anterior 2/3 of the tongue

Answer 47

lingual nerve

Question 48

supplies sensation to the chin

Answer 48

mental nerve

Question 49

the mandibular nerve (V3) carries proprioceptive information from muscles of mastication to brainstem in order to control

Answer 49

the force of the bite

Question 50

cranial nerve VII is called the:

Answer 50

facial nerve

Question 51

what type of nerve is the facial nerve (CN VII)?

Answer 51

mixed nerve (mostly somatic motor, some somatic sensory and parasympathetic)

Question 52

what part of the brainstem does the facial nerve come off of?

Answer 52

the pons

Question 53

sensory nerve cell bodies of the facial nerve are found in the:

Answer 53

geniculate ganglion

Question 54

what is the motor function of the facial nerve (CN VII)?

Answer 54

controls the muscles of facial expression (five sets of branches)

Question 55

what are the five main branches of the facial nerve?

Answer 55

1) temporal branch 2) zygomatic branch 3) buccal branch 4) manibular branch 5) cervical branch

Question 56

special branch of the facial nerve that supplies sensory (taste) information of the anterior 2/3 of the tongue

Answer 56

chorda tympani nerve (joins lingual nerve)

Question 57

provides parasymapathetic stimulation to the lacrimal gland for tearing

Answer 57

pterygopalatine ganglion

Question 58

provides parasympathetic stimulation to the submandibular and sublingual salivary glands

Answer 58

submandibular ganglion

Question 59

damage or disease of the facial nerve leads to:

Answer 59

partial loss of taste, salivation, or lacrimation, and Bell's palsy (hemi-facial paralysis)

Question 60

cranial nerve VIII is called the:

Answer 60

vestibulocochlear nerve

Question 61

what type of nerve is the vestibulocochlear nerve (CN VIII)?

Answer 61

pure sensory nerve

Question 62

what are the two components of the vestibulocochlear nerve?

Answer 62

vestibular and cochlear

Question 63

what type of sensory information comes from the vestibular apparatus?

Answer 63

balance and equilibrium

Question 64

disease of the vestibular branch of CN VIII leads to:

Answer 64

Meniere's syndrome (vertigo, nausea, and vomiting)

Question 65

what type of sensory information comes from the organ of corti in the cochlea?

Answer 65

hearing

Question 66

the bilateral central pathway in the brainstem carries auditory information to the:

Answer 66

primary auditory cortex (temporal lobe)

Question 67

damage or disease of the cochlear branch of CN VIII leads to:

Answer 67

difficulty in localizing sound

Question 68

cranial nerve IX is called the:

Answer 68

glossopharyngeal nerve

Question 69

what type of nerve is the glossopharyngeal nerve?

Answer 69

mixed nerve (somatic motor, somatic sensory, and parasympathetic)

Question 70

what part of the brainstem is CN IX attached to?

Answer 70

medulla

Question 71

what is the function of the glossopharyngeal nerve (CN IX)?

Answer 71

supplies the tongue (touch and taste) and pharynx, regulates the gag reflex

Question 72

damage or disease of the glossopharyngeal nerve leads to:

Answer 72

difficulty in swallowing and loss of gag reflex

Question 73

CN IX supplies motor information to one muscle. what is that muscle and its function?

Answer 73

stylopharyngeus (elevates pharynx)

Question 74

what are the sensory functions of the glossopharyngeal nerve?

Answer 74

posterior 1/3 of tongue (touch and taste), pharynx, and carotid sinus/body (dip stick for oxygen concentration)

Question 75

the glossopharyngeal nerve supplies parasympathetic infromation to the parotid gland via the:

Answer 75

otic ganglion

Question 76

cranial nerve X is called the:

Answer 76

vagus nerve

Question 77

what type of nerve is the vagus nerve (CN X)?

Answer 77

mixed nerve (motor, sensory, and parasympathetic)

Question 78

what part of the brainstem is CN X attached to?

Answer 78

the medulla

Question 79

damage or disease of the vagus nerve leads to:

Answer 79

difficulty in speech and swallowing

Question 80

what is the somatic motor function of the vagus nerve?

Answer 80

controls the muscles of the palate, pharynx and larynx

Question 81

what are the sensory functions of the vagues nerve?

Answer 81

- sensation to the palate, pharynx, and larynx (talking) - baroreceptors sense stretch in the stomach and bowel - carries visceral afferents from the organs to the CNS and tells the brain to increase digestion

Question 82

what are the parasympathetic functions of the vagus nerve?

Answer 82

- parasympathetic nerve for viscera - motor control to smooth muscle in thoracic and abdominal organs up to the distal part of the transverse colon - regulates heart rate (slows it down)

Question 83

cranial nerve XI is called the:

Answer 83

spinal accessory nerve

Question 84

what type of nerve is the spinal accessory nerve?

Answer 84

somatic motor only

Question 85

what is the function of the spinal accessory nerve?

Answer 85

supplies motor commands to the trapezius and sternocleidomastoid muscles in the neck

Question 86

what part of the CNS is the spinal accessory nerve attached to?

Answer 86

the medulla and upper spinal cord

Question 87

damage or disease of the spinal accessory nerve leads to:

Answer 87

weakness when elevating shoulders, and turning head to one side

Question 88

cranial nerve XII is called the:

Answer 88

hypoglossal nerve

Question 89

what type of nerve is the hypoglossal nerve (CN XII)?

Answer 89

motor

Question 90

what part of the brainstem is the hypoglossal nerve attached to?

Answer 90

the medulla

Question 91

supplies motor commands to the muscles of the tongue

Answer 91

hypoglossal nerve (CN XII)

Question 92

damage or disease of the hypoglossal nerve leads to:

Answer 92

inability to protrude tongue symmetrically

Question 93

cranial nerve VI is called the:

Answer 93

abducent nerve

Question 94

what type of nerve is the abducent nerve and what is its function?

Answer 94

pure motor, controls the lateral rectus muscle (abducts the eye)

Question 95

where is the abducent nerve located?

Answer 95

the pontomedullary junction (b/w the pons and medulla)

Question 96

which cranial nerve is the longest?

Answer 96

the abducent nerve (CN VI)

Question 97

damage of the abducent nerve leads to:

Answer 97

paralysis of the lateral rectus (eye deviates medially) and patient complains of double vision (diplopia)