Neuro Lecture 9 (pt. 2): CN VIII, IX, X, XI, XII

0.0(0)
studied byStudied by 0 people
learnLearn
examPractice Test
spaced repetitionSpaced Repetition
heart puzzleMatch
flashcardsFlashcards
Card Sorting

1/84

encourage image

There's no tags or description

Looks like no tags are added yet.

Study Analytics
Name
Mastery
Learn
Test
Matching
Spaced

No study sessions yet.

85 Terms

1
New cards

What are the 2 divisions of the ear (CN VIII)?

- Bony labyrinth

- Membranous labyrinth

2
New cards

What does the bony labyrinth contain (CN VIII)?

Perilymph

3
New cards

What does the membranous labyrinth contain (CN VIII)?

Endolymph

4
New cards

What are the 3 components that the membranous labyrinth contains (CN VIII)?

- Cochlea

- Semicircular canals

- Otolith organs

<p>- Cochlea</p><p>- Semicircular canals</p><p>- Otolith organs</p>
5
New cards

What does the cochlea contain (CN VIII)?

Hair cells (receptors) for hearing

6
New cards

What do the semicircular canals contain (CN VIII)?

Hair cells that respond to angular accelerations

7
New cards

What do the otolith organs contain (CN VIII)?

Hair cells that respond to linear accelerations

8
New cards

What does higher frequency sound/pitch activate (CN VIII)?

- Hair cells near oval window

- Birds, children, alarms

9
New cards

What does lower frequency sound/pitch activate (CN VIII)?

Hair cells near apex of cochlea

10
New cards

Where does the cochlear nerve synapse (CN VIII)?

Dorsal/ventral cochlear nuclei

11
New cards

How does auditory pathway cross (CN VIII)?

- Bilaterally at multiple points

- No unilateral hearing loss with lesions above cochlear nuclei

12
New cards

What are the 2 auditory pathways of the cochlear nerve (CN VIII)?

- Primary lemniscal

- Non-lemniscal

13
New cards

What is the primary lemniscal pathway responsible for (CN VIII)?

- Carries information from both ears to primary auditory cortex

- Conscious hearing and recognition of sounds

14
New cards

What is the first step of the primary lemniscal pathway (CN VIII)?

Primary sensory neurons in spinal ganglion send axons in cochlear division

15
New cards

What is the second step of the primary lemniscal pathway (CN VIII)?

Dorsal/ventral cochlear nuclei

16
New cards

What is the third step of the primary lemniscal pathway (CN VIII)?

Superior olivary nucleus

17
New cards

What is the fourth step of the primary lemniscal pathway (CN VIII)?

Inferior colliculus

18
New cards

What is the fifth step of the primary lemniscal pathway (CN VIII)?

MGN of thalamus

19
New cards

What is the sixth step of the primary lemniscal pathway (CN VIII)?

Auditory cortex (Heschl's gyrus)

20
New cards

What is the non-lemniscal pathway responsible for (CN VIII)?

- Unconscious perception of attention, awareness, auditory reflexes, emotional responses

- Via reticular formation

- Orients head and eye to location of sound

- Alerts to impending danger

21
New cards

What causes unilateral hearing loss (CN VIII)?

- Abnormalities of external auditory canal, middle ear, cochlea

- Injury of CN VIII, dorsal/ventral cochlear nuclei

22
New cards

What are 2 types of unilateral hearing loss (CN VIII)?

- Conductive

- Sensorineural

23
New cards

What is conductive hearing loss (CN VIII)?

Abnormalities of external auditory canal or middle ear

24
New cards

What causes conductive hearing loss (CN VIII)?

- Otitis

- Tympanic membrane perforation

25
New cards

What is sensorineural hearing loss (CN VIII)?

Disorders of cochlea or CN VIII

26
New cards

What causes sensorineural hearing loss (CN VIII)?

- Exposure to loud sounds

- Meniere's disease

- Tumor

27
New cards

Where can you find the vestibular anatomy (CN VIII)?

- Posterior to the cochlea

- Filled with endolymph

28
New cards

What does the vestibular anatomy consist of (CN VIII)?

- 3 semicircular canals

- Otolith organ

- Utricle and saccule

29
New cards

What structures are a part of the semicircular canals (CN VIII)?

Anterior/posterior/lateral semicircular canals

<p>Anterior/posterior/lateral semicircular canals</p>
30
New cards

What sensory organ is a part of the semicircular canals (CN VIII)?

Ampulla

31
New cards

What is the function of the semicircular canals (CN VIII)?

- Sensing angular head motion in different directions

- Helps keep eyes steady when head is moving

- Vestibular ocular reflex (VOR)

<p>- Sensing angular head motion in different directions</p><p>- Helps keep eyes steady when head is moving</p><p>- Vestibular ocular reflex (VOR)</p>
32
New cards

What is the ampulla (CN VIII)?

The structure in which hair cells are located

33
New cards

What is seen with increased activity in semicircular canals (CN VIII)?

- Complimentary

- Increased activity in one ear inhibits activity in the other

- Allows for better balance and stable vision

<p>- Complimentary</p><p>- Increased activity in one ear inhibits activity in the other</p><p>- Allows for better balance and stable vision</p>
34
New cards

What structures are a part of the otolith organs (CN VIII)?

Utricle and saccule

<p>Utricle and saccule</p>
35
New cards

What sensory organ is a part of the otolith organs (CN VIII)?

- Macula

- Hair cells sensitive to movement in straight lines

<p>- Macula</p><p>- Hair cells sensitive to movement in straight lines</p>
36
New cards

What is the function of the otolith organs (CN VIII)?

Sense position of the head with respect to gravity (linear acceleration)

37
New cards

What is the utricle sensitive to (CN VIII)?

Vertical acceleration, orientation, balance

38
New cards

What is the saccule sensitive to (CN VIII)?

Horizontal acceleration, deceleration of head in horizontal plane

39
New cards

What is benign paroxysmal positional vertigo (CN VIII)?

- Inner ear disorder

- Feeling that everything is spinning in/around

40
New cards

What causes benign paroxysmal positional vertigo (CN VIII)?

Otolith move out of place and enter semicircular canals

41
New cards

How do you test for benign paroxysmal positional vertigo (CN VIII)?

- Dix-Hallpike (Nylén-Bárány) Test

- +ve with nausea and nystagmus

- -ve if dizzy but no nystagmus

42
New cards

What characteristics set apart peripheral vertigo (CN VIII)?

- Sudden and memorable onset

- Client will be able to give you a date/time

43
New cards

What characteristics set apart central vertigo (CN VIII)?

- Slow onset

- Client will not be able to tell you when symptoms started

44
New cards

What are the functions of the vestibular system (CN VIII)? (6)

- Proprioception

- Muscle tone and postural control

- Head positioning and movement in relation to gravity

- Balance

- Bilateral integration

- Alertness and arousal

45
New cards

What is proprioception responsible for (CN VIII)?

Awareness of body position and movement in space

46
New cards

What are muscle tone and postural control responsible for (CN VIII)?

- Influences proprioception

- Via medial/lateral vestibular spinal tract

47
New cards

What is head positioning and movement in relation to gravity responsible for (CN VIII)?

Head stability and midline orientation

48
New cards

What falls under the responsibilities of balance (CN VIII)?

- Gaze stability

- Gait stability

- Spatial awareness

49
New cards

What signs are associated with dysfunction of alertness and arousal in the vestibular system (CN VIII)?

- Nausea

- Vomiting

- Altered consciousness

50
New cards

What muscle does the branchial motor neuron associated with the glossopharyngeal nerve innervate (CN IX)?

Stylopharyngeus muscle

<p>Stylopharyngeus muscle</p>
51
New cards

What gland is associated with the parasympathetic aspect of the glossopharyngeal nerve (CN IX)?

Parotid gland (salivation)

<p>Parotid gland (salivation)</p>
52
New cards

What does the general sensory neuron associated with the glossopharyngeal nerve innervate (CN IX)?

- Posterior 1/3 of tongue

- Pharynx

- Auditory meatus

<p>- Posterior 1/3 of tongue</p><p>- Pharynx</p><p>- Auditory meatus</p>
53
New cards

What is the special sensory neuron associated with the glossopharyngeal nerve responsible for (CN IX)?

Taste from posterior 1/3 of tongue

<p>Taste from posterior 1/3 of tongue</p>
54
New cards

What receptors make up visceral sensory neurons associated with the glossopharyngeal nerve innervate (CN IX)?

Chemoreceptors and baroreceptors of carotid body

<p>Chemoreceptors and baroreceptors of carotid body</p>
55
New cards

What are the important functions of CN IX?

- Special sensory

- Visceral sensory

- Other: gag reflex

<p>- Special sensory</p><p>- Visceral sensory</p><p>- Other: gag reflex</p>
56
New cards

Which cranial nerve is also known as the "wandering nerve"?

CN X (vagus nerve)

57
New cards

What parts of the body are affected by CN X? (8)

- Larynx

- Trachea

- Bronchi

- Lungs

- Heart

- GI tract

- Liver

- Pancreas

58
New cards

Which organs receive parasympathetic innervation from the vagus nerve (CN X)?

- Heart

- Lungs

- Digestive tract

- Down to splenic flexure

59
New cards

Which muscles receive motor innervation from the vagus nerve (CN X)?

Pharyngeal and laryngeal muscles

<p>Pharyngeal and laryngeal muscles</p>
60
New cards

Which areas receive general sensory innervation from the vagus nerve (CN X)?

- Pharynx

- Meninges

- External auditory meatus

<p>- Pharynx</p><p>- Meninges</p><p>- External auditory meatus</p>
61
New cards

What is the special sensory innervation from the vagus nerve responsible for (CN X)?

Taste for the epiglottis and posterior pharynx

62
New cards

What makes up the visceral sensory innervation from the vagus nerve (CN X)?

Baroreceptor and chemoreceptor of aortic arch

<p>Baroreceptor and chemoreceptor of aortic arch</p>
63
New cards

What tests can an OT do for CN IX and CN X?

- Palate elevation

- Gag reflex

<p>- Palate elevation</p><p>- Gag reflex</p>
64
New cards

What is dyspnea?

- Difficulty breathing if visceral branch of vagus nerve is damaged

- CN X pathology

65
New cards

What is dysphonia?

Hoarse voice

66
New cards

What is dysphagia?

Difficulty swallowing

67
New cards

What is dysarthria?

Difficulty enunciating words

68
New cards

What is the first step of the pathway of the spinal accessory nerve (CN XI)?

Arises in medulla and upper 5-6 cervical segments

69
New cards

What is the second step of the pathway of the spinal accessory nerve (CN XI)?

Ascend through foramen magnum to reach intracranial cavity

70
New cards

What is the third step of the pathway of the spinal accessory nerve (CN XI)?

Exits cranium via jugular foramen

71
New cards

What is the function of the branchial motor neurons associated with the spinal accessory nerve (CN XI)?

- Elevation of larynx with swallowing

- SCM for turning head in opposite direction

- Upper trapezius elevates shoulder and maintain head extension

72
New cards

Is the lower portion of the trapezius supplied by CN XI?

No, mainly supplied by cervical nerve roots C3 and C4

73
New cards

What are signs and symptoms of CN XI pathology? (5)

- Dysphasia

- Laryngeal elevation

- Weakness rotating head contralaterally

- Weakness flexing/extending head

- Difficulty elevating shoulder or involved arm above 90º

74
New cards

What is the function of the hypoglossal nerve (CN XII)?

- Somatic motor

- Tongue movement

75
New cards

What is the first step of the pathway of the hypoglossal nerve (CN XII)?

Motor pathway decussates and then synapses on hypoglossal nucleus

76
New cards

What is the second step of the pathway of the hypoglossal nerve (CN XII)?

Exits between pyramid and inferior olivary nucleus

77
New cards

What does an UMN lesion of the hypoglossal nerve affect (CN XII)?

- Primary cortex

- Internal capsule (corticobulbar)

- Contralateral weakness of tongue

78
New cards

What does a LMN lesion of the hypoglossal nerve result in (CN XII)?

- Ipsilateral weakness of tongue

- Fasciculations

- Atrophy

79
New cards

What is an OT testing for with CN XII pathology?

- Tongue protrusion

- Unilateral weakness

- Tongue deviates toward weak side when protruded

80
New cards

What are signs and symptoms of CN XII pathology?

- Dysarthria

- Dysphagia

81
New cards

What are causes of dysarthria with CN XII pathology? (4)

- Infarct

- MS

- Brainstem lesions

- Lesions of cerebellar and basal ganglia pathways

82
New cards

What are causes of dysphagia with CN XII pathology? (5)

- Infarcts

- Neoplasms

- Esophageal strictures (narrowing)

- Neural components

- Aspiration pneumonia (serious!)

83
New cards

What is the cranial nerve combination involved in dysphagia?

- CN V

- CN VII

- CN XI (head control)

- CN X

- CN XII

84
New cards

What is the cranial nerve combination for innervation of the face?

- CN V (sensation)

- CN VII (movement of facial expression)

85
New cards

What is the cranial nerve combination for functions of the tongue and mouth?

- CN V mandibular division (general sensory)

- CN IX (general sensory)

- CN VII (special sensory)

- CN IX (special sensory)

- CN X (epiglottis and posterior pharynx)