N16 & N17 - Cranial nerves Flashcards
(95 cards)
1
Q
where are cranial nerves visible?
A
ventral aspect of brain
2
Q
Name all the cranial nerves.
A
I. Olfactory II. Optic III. Oculomotor IV. Trochlear V. Trigeminal VI. Abducent VII. Facial VIII. Vestibulocochlear IX. Glossopharyngeal X. Vagus XI. Accesssory XII. HYpoglossal
3
Q
What cranial nerves are only sensory?
A
I. Olfactory
II. Optic
VIII. Vestibulocochlear
4
Q
what cranial nerves are only motor?
A
IV. Trochlear
VI. Abducent
XI. Accessory
XII. Hypoglossal
5
Q
What cranial nerves are mixed?
A
V. Trigeminal
VII. Facial
IX. Glossopharyngeal
X. Vagus
6
Q
where does most of the cranial nerves exit the brain and what are the 2 exceptions?
A
Nerves exit anteriorly except IV which exits posteriorly (wrap arounds the brain stem) and VIII which exits laterally
7
Q
what do the cranial nerves do?
A
sensation and motor to the head except Vagus which is the wanderer
8
Q
Where do the cranial nerves exit the cranial cavity?
A
I. cribriform plate of ehtmoid II. Optic canal III, IV, VI. superior orbital fissure Va. Superior orbital fissure Vb. Foramen rotunda Vc. Foramen ovale VII, VIII. internal acoustic meatus IX, X, XI . Jugular foramen XII. Hypoglossal canal
9
Q
what nerve does not leave the cranial cavity?
A
VIII as it terminates in the bone
10
Q
what is each component of cranial nerve associated with?
A
a streak/blob of grey matter in the brain/brain stem which serves one function
11
Q
what are motor components associated with?
A
motor nuclei, groups of efferent nerve cells that send their axons into the cranial nerve
12
Q
what are sensory components associated with?
A
sensory nuclei, groups of nerve cells upon which the sensory neurons of the cranial nerves synapse
13
Q
where are the soma of the sensory nerve cells found?
A
In ganglia outside of the central nervous system (analogous to the Dorsal Root Ganglion for the spinal nerves)
14
Q
How many motor and sensory components are there?
A
- 3 motor components
- 3 sensory components
15
Q
What is different about the olfactory nerve?
A
Only sensory modality that does not synapse in the thalamus prior to reaching the cortex (only neurone directly exposed to outside world)
16
Q
How does the olfactory nerve reach the cortex?
A
Arrives in olfactory bulb and neurones form olfactory tract which is delivered to primary olfactory cortex
17
Q
What information arrives posterior in the spinal cord?
A
sensory
18
Q
what information exits anterior in the spinal cord?
A
motor
19
Q
In part of the brainstem near the 4th ventricle, where do sensory and motor end up?
A
Sensory ends up lateral and motor ends up medial
20
Q
where does spinal accessory originate?
A
in the spinal cord
21
Q
What are the 3 motor components?
A
- somatic motor
- Visceral motor (parasympathetic)
- Branchio motor
22
Q
what is the structure/fucntion of somatic motor?
A
Skeletal muscle somites
(eye-extracolular muscles, tongue)
23
Q
What cranial nerves are associated with somatic motor ?
A
CN III, IV, VI, XII
24
Q
Where are the nuclei of somatic motor cranial nerves found?
A
near the midline
25
What modalities is oculomotor (III)?
- Somatic motor
| - Parasympathetic
26
What does the oculomotor supply?
- Somatic motor - levator palpebral superioris, Superior/middle/inferior rectus and inferior oblique
- Parasympathetic- sphincter papillae cilliary muscle
27
What modalities is the trochlear(IV)?
somatic motor
28
What does the trochlear never supply?
-Somatic motor- superior oblique
29
Where do trochlear fibres go after leaving trochlear nucleus?
exit posteriorly all the way round the aquaduct
30
where is oculomotor found in brain?
Upper midbrain midline
31
where is trochlear found in the brain?
lower midbrain midline
32
what modalities is abducent (VI)?
somatic motor
33
where is abducent found in the brain?
caudal pons
34
What modalities is hypoglossal (XII)?
somatic motor
35
what does the hypoglossal nerve supply?
Somatic motor to genioglossal, hypoglossal , styloglossus and intrinsic muscles
36
where is the hypoglossal nerve found in the brain?
medulla
37
If there is a defect in the hypoglossal nerve , what side does the tongue point if you stick it out?
points to defect side
38
what is the structure/fucntion of visceral motor?
Glands/smooth muscle
| head + thorax, GI tract
39
What nerves are visceral motor (parasympathetic)?
- Oculomotor (III)
- Facial (VII)
- Glossopharyngeal (IX)
- Vagus (X)
40
what is the visceral motor oculomotor nucleus and what does it supply?
- Accessort oculumotor nucleus (Edinger-westphal nucleus)
| - Pupillary sphincter colliery muscle
41
what is the visceral motor facial nucleus and what does it supply?
- Superior salvitory nucleus
| - Submandibular and pterygopalatine ganglion
42
what is the visceral motor glossopharyngeal nucleus and what does it supply?
- inferior salivary nucleus
| - otic ganglion
43
what is the visceral motor vagus nucleus and what does it supply?
-Dorsal nucleus of vagus
- Glands + smooth muscle
of viscera - Heart, Airways, Lungs, GI Tract
44
what is the structure/ site of branch motor (pharyngeal arch musculature; Special Visceral Efferents)?
Jaw, Face, Pharynx, larynx, head/shoulders
45
what nerves carry the branchiomotor component?
- Trigeminal (V)
- Facial (VII)
- Glossopharyngeal (IX)
- Vagus (X)
- Cranial accessory(XI)
46
What is the branchiomotor trigeminal nucleus and what does it supply?
- Trigeminal nucleus
| - Jaw muscles, t.tymp, t. palatini, Mylohyoid, anterior belly digastric
47
what is the branchiomotor facial nucleus and what does it supply?
- Facial motor nucleus
| - muscles of facial expression, stapedius
48
what is the branchiomotor glossopharyngeal nucleus and what does it supply?
- ambiguus nucleus
| - swallowing (stylopharyngeus)
49
what is the branchiomotor vagus nucleus and what is its function?
- ambiguus nucleus
| - Swallowing, palate-up , talking
50
what is the branchiomotpr cranial accessory nucleus and what is its function?
- ambiguus nucleus
| - palate-up, talking
51
what provides motor to the cranial nerves?
The corticobulbar tract is the part of the pyramidal tract that is motor to the cranial nerves.
This includes fibres to the motor nuclei of CN’s V, VII, X, and XII
52
describe the input to the facial nucleus in the upper and lower part of the head.
the input to the facial nucleus is only bilateral to that part that controls the upper part of the face (forehead and around the eyes), but only a crossed input reaches the part of the facial nucleus that controls muscles in the lower half of the face
53
Are fibres for the lower portion of the face ipsilateral,contralateral or bilateral?
bilateral
54
Are fibres for the upper portion of the face ipsilateral,contralateral or bilateral?
contralateral aka if there is lesion on the upper face , there is only lower face weakness on the opposite side
55
what are the 3 sensory components?
1). General sensations of pain, touch, position (V nerve nuclei) – General Somatic Afferents
2) . General and Special visceral sensations: input from organs and taste (solitary nucleus)
- General and Special Visceral Afferents
3) . Special "head" sensations hearing, balance and vision
- Special Somatic Afferent (SSA)
56
In the opening out of the back of the Brain stem, where does visceral sensation, somatic sensation and hearing/balance sit in terms of one another?
- Visceral sensation( taste and information from viscera) is most medial
- Somatic sensation (Discriminative touch, pain and temp) is lateral to visceral sensation
- Hearing and balance is out lateral
57
Name the 3 trigeminal sensory nuclei.
- Mesencephalic nuclues
- Pontine trigeminal nucleus (principal nucleus)
- Spinal nucleus
58
what trigeminal sensory nucleus is involved with proprioceptive information?
Mesencephalic nucleus
59
what trigeminal sensory nucleus is involved in discriminative touch/vibration?
Pontine trigeminal nucleus
60
what trigeminal sensory nucleus is involved in pain/temp?
Spinal nucleus
61
what does the sensory nucleus of the trigeminal form?
long column of neurons that stretches from the midbrain down to the upper 2 segments of the cervical spinal cord.
62
what are the 3 parts of the sensory nucleus of the trigeminal separated by?
function
63
what information arrives at the mesencephalic nucleus?
Proprioceptive information from teeth and jaw
64
what is unusual about the mesencephalic nucleus?
the only site in the CNS where the cell bodies of the primary afferent neurons live inside the CNS
65
what is the advantages of the mesencephalic nucleus proximity to the motor nucleus?
advantages in terms of jaw reflexes
66
where does the trigeminothalamic tract begin and end?
Trigeminal to thalamus
67
What is caused by not all fibres crossing the midline in the trigeminothalamic tract?
bilateral representation of touch, vibration in cortex
68
Describe the fibres in the ventral trigeminothalamic tract.
all fibres are crossed
69
what does the trigeminal nucleus merge with?
dorsal horn
70
Describe the organisation of trigeminal pain fibres.
the lower regions of the trigeminal nucleus carry information for the peripheral of the face. The higher up the trigeminal nucleus you travel,you move inwards to the perioral region of the face
71
what additional cranial nerves have small sensory input into the spinal nucleus and for what function?
- CN VII, IX, X
| - For general sensation and pain and temperature around ear
72
what is the auricular branch of vagus also known as?
Alderman’s nerve
73
what does stimulation of alderman's nerve cause?
produce vomiting
74
what nuclei in the brainstem is shared between CN VII and IX and what does it carry?
Sup. and Inf. Salivatory nuclei (parasympathetic efferents to ganglia of salivary glands and pterygopalatine ganglion)
75
what nuclei in the brainstem is shared by CN IX and X and cranial part of XI and what does it carry?
Nucleus ambiguus (motor efferents to muscles of pharynx, larynx and upper oesophagus)
76
what nuclei in the brainstem is shared by CN VII,IX and X and what does it carry?
Solitary nucleus (taste and visceral sensory information)
77
Describe the shape of the solitary nucleus.
Extends in a ‘V’ shape from upper to mid medulla
78
what are the 2 parts of the solitary nucleus?
- Gustatory nucleus (taste afferents :special visceral afferents)
- Commissural nucleus (visceral afferents : general visceral afferents
79
what nerve supplies the anterior 2/3 of the tongue?
CN VII -facial
80
what nerve supplies the posterior 1/3 of the tongue?
CN IX
81
what nerve supplies the epiglottis?
CN X - vagus
82
what nerve supplies the carotid sinus/body?
CN IX
83
what nerve supplies the aortic arch + visceral (e.g. pulmonary stretch receptors)?
CN X
84
In what other way does visceral information, particularly pain sensation reach the CNS?
sympathetic pathways via spinal cord
85
Name 3 complex cranial nerves.
- Facial VII
- Glossopharyngeal IX
- Vagus X
86
What are the functions of the facial nerve?
1. Motor (muscles of facial expression, stapedius) (SVE).
2. Parasymp. innervation to pterygopalatine and submandibular ganglia (GVE) 3. Taste (anterior 2/3 of tongue via c. tympani) (SVA)
4. Somatosensation to small region around the ear (GSA)
87
what are the functions of the glossopharyngeal nerve CN IX?
1. Tactile sense, pain and temperature sense from posterior tongue, pharyngotymapnic tube and upper pharynx (GSA)
2. Taste (posterior 1/3 of the tongue) (SVA)
3. Visceral sensation from carotid sinus and carotid body (GVA)
4. Motor (one muscle: stylopharyngeus) (SVE)
5. Parasympathetic innervation to the otic ganglion (parotid gland) (GVE)
88
what are the functions of the vagus nerve?
1. Parasympathetic innervation to ganglia serving thoracic and abdominal viscera (GVE).
2. Motor (striated muscle of the pharynx and larynx) (cranial accessory contributes to this function) (SVE).
3. Tactile sense, pain and temperature sense from the lower pharynx, larynx, oesophagus, dura (pain), (and small area around the ear) (GSA)
4. Visceral afferents from aorta, lung, gut etc. (GVA)
5. Taste (epiglottis) (SVA)
89
what are the 5 components of the facial nerve?
1. Facial motor nucleus :muscles official expression (SVE)
2. Salivatory nucleus: parasympathetic innervation of submandibular and pterygopalatine gangllion (GVE)
3. Solitary nucleus: taste from the anteror 2/3 of tongue (SVA)
4. Spinal trigeminal nucleus: small region of somatosensation associated with the ear (small) (GSA).
5. ??
90
what does the fibres from the motor nucleus loop around?
abducens nucleus
91
What are the 5 components of the glossopharyngeal?
1. Spinal trigeminal n.: sensation from upper p hayrnx, post. tongue (and small region of somatosensation associated with the ear) (GSA).
Solitary nucleus:
2. Gustatory nucleus – taste (SVA), &
3. Commissural nucleus- visceral information (GVA). 4. Nucleus ambiguus:
stylopharyngeus muscle (SVE)
5. Inf. Salivatory nucleus parasympathetic to otic ganglion (GVE)
92
where is the facial nerve found in the brain?
caudal pons
93
where is the glossopharyngeal nerve found int the brain?
upper medulla
94
what are the 5 components of the vagus nerve?
1. Dorsal (motor) Nucleus: (parasympathetic innervation of most viscera) (GVE)
2.Nucleus Ambiguus
(motor: pharynx & larynx) (SVE)
3. Spinal trigeminal nucleus (pain from dura and small region of somato-sensation associated with the ear) (GSA)
Solitary nucleus:
4. Commissural nucleus- visceral information (GVA).
&
5. Gustatory nucleus – taste (SVA)
95
where is the vagus nerve found in the brain stem?
upper medulla
