Lecture 45 Cranial Nerves 1 Flashcards
1
Q
Which region of the skull is most intimately tied to the cranial nerves?
A
the foramina of the chondrocranial base
2
Q
What are our “two skulls” in humans?
A
chondrocranial base and the desmocranium
3
Q
Which of our two skulls is under tighter evolutionary control?
A
chondrocranial base
4
Q
Name the twelve cranial nerves.
A
Olfactory, Optic, Oculomotor, Trochlear, Trigeminal, Abducens, Facial, Vestibulo-Cochlear, Glossopharyngeal, Vagus, Spinal Accessory, Hypoglossal
5
Q
Cranial Nerve I
A
Olfactory
6
Q
Cranial Nerve II
A
Optic
7
Q
Cranial Nerve III
A
Oculomotor
8
Q
Cranial Nerve IV
A
Trochlear
9
Q
Cranial Nerve V
A
Trigeminal
10
Q
Cranial Nerve VI
A
Abducens
11
Q
Cranial Nerve VII
A
Facial
12
Q
Cranial Nerve VIII
A
Vestibulo-Cochlear
13
Q
Cranial Nerve IX
A
Glossopharyngeal
14
Q
Cranial Nerve X
A
Vagus
15
Q
Cranial Nerve XI
A
Spinal Accessory
16
Q
Cranial Nerve XII
A
Hypoglossal
17
Q
The _____ is defined as the brain and the spinal cord. The _____ includes all nerves and neural structures which lie outside that.
A
Central Nervous System (CNS)
Peripheral Nervous System (PNS)
18
Q
The PNS consists of _____ pairs of spinal nerves which exit the cord segmentally, the ____ pairs of cranial nerves originating from the brain and the ______.
A
31
12
Autonomic Nervous System (ANS)
19
Q
What system is used to classify the 12 cranial nerves along functional and evolutionary lines into a more understandable grouping?
A
3-4-5 System of Subdividing Cranial Nerves; Special Sensory, Myotomal, Branchiomeric
20
Q
Cranial nerves may have as many as _____ types of fibers, but the max number found is _____.
A
7; 5
21
Q
What is the general function of special visceral afferent (SVA) fibers?
A
convey taste and smell from the nasal, buccal, and pharyngeal areas to the appropriate areas of the cortex
22
Q
What type of fibers found in the head and neck carry sensory information from ectodermal placodal (cranial placodes that have neurogenic potential ie. those that give rise to neurons associated with the special senses and cranial ganglia) structures such as the eye and ear?
A
special somatic afferent (SSA) fibers
23
Q
Why is smell classified as visceral when discussing fibers?
A
It is considered visceral on the basis of gustatory function (relating to the gut)
24
Q
What type of special fiber is NOT found in the head and neck?
A
Special Somatic Efferents (SSE)
25
What three nerves are part of the special sensory nerves grouping?
Olfactory (CN I), Optic (CN II), and Vestibulo-Cochlear (CN VIII)
26
Why are cranial nerves I, III, and VIII called the special sensory nerves?
They are classified as only containing afferent fibers, CN I contains SVA and CN II and VIII contain SSA
27
The nasal palcode and its derivative the olfactory epithelium are classified as what?
special visceral afferent (SVA)
28
Groups of SVA filaments originate high on the nasal septum, in the supreme or superior conchae, pass in ____ to ___ small nerve bundles, or the olfactory "nerves", through the _____ of the _____ bone to enter and synapse with cells in the olfactory bulb.
12 to 20
Cribriform plate
Ethmoid
29
The bulb and tract of CN I are conventionally referred to as what?
Olfactory nerve
30
Vision is carried by what type of fibers?
Special somatic afferent (SSA)
31
Fibers from both nasal retinal areas cross at the ______ so that information from the R visual field ends up at the L occipital (visual) cortex, and from the L visual field in the R occipital pole.
optic chaisma
32
Since vision brings information from afar, what is this sense sometimes classified as?
Telereceptive
33
What foramen does the Olfactory nerve (CN I) pass through?
Cribriform plate of ethmoid bone
34
What foramen does the Occipital Nerve (CN II) pass through?
Optic canal (lesser wing of sphenoid bone)
35
What foramen does the Oculomotor nerve (CN III) pass through?
Superior Orbital Fissure (bound by both wings of sphenoid)
36
What foramen does the Trochlear nerve (CN IV) pass through?
Superior Orbital Fissure (bound by both wings of sphenoid)
37
What foramen does the Opthalmic division of the Trigeminal Nerve (CN V1) pass through?
Superior Orbital fissure (bound by both wings of sphenoid)
38
What foramen does the Maxillary division of Trigeminal Nerve (CN V2) pass through?
Foramen Rotundum (base of greater wing of sphenoid)
39
What foramen does the Mandibular division of Trigeminal Nerve (CN V3) pass through?
Foramen Ovale (positioned posterolaterally to foramen rotundum)
40
What foramen does the Abducens Nerve (CN VI) pass through?
Superior Orbital Fissure (bound by both wings of sphenoid)
41
What foramen does the Facial Nerve (VII) pass through?
Internal Acoustic Meatus (temporal bone)
42
What foramen does the Vestibulo-Cochlear Nerve (CN VIII) pass through?
Internal Acoustic Meatus (temporal bone)
43
What foramen does the Glossopharyngeal Nerve (CN IX) pass through?
Jugular Foramen (anteriorly by temporal bone and posteriorly by occipital bone)
44
What foramen does the Vagus Nerve (CN V) pass through?
Jugular Foramen (anteriorly by temporal bone and posteriorly by occipital bone
45
What foramen does the Spinal Accessory Nerve (CN XI) pass through?
Jugular foramen (anteriorly by temporal bone adn posteriorly by occipital bone)
46
What foramen does the Hypofglossal Nerve (CN XII) pass through?
Hypoglossal Canal (occipital bone)
47
Describe the two classes of the special somatic afferents (SSA) of the Vestibulo-Cochlear nerve (CN VIII).
Telereceptive fibers that convey information regarding the amplitude, frequency, and length of sound which is transduced within the cochlear portion of the ear
Other SSAs are concerned with the proprioceptive information considering the position or acceleration of the body in space; transduced along the vestibular components of this nerve
48
Describe the scheme of distribution of the Vestibulo-Cochlear Nerve (CN VIII).
This nerve has two parts: (1) the cochlear nerve or nerve of hearing whose fibers transmit impulses from the spinal organ of Corti in the cochlear duct (2) the vestibular nerve or the nerve of balance whose fibers transmit impulses from the maculae of the saccule and utricle and ampulae of the three semicircular ducts
49
Name the four myotomal nerves.
Oculomotor (CN III), Trochlear (CN IV), Abducens Nerve (CN VI), and Hypoglossal (CN XII)
50
Which three myotomal nerves move the muscles of the eyeball?
Oculomotor (CN III), Trochlear (CN IV), and Abducens (CN VI)
51
Name the muscles supplied by the Oculomotor Nerve (CN III).
inferior oblique, medial rectus, inferior rectus, superior rectus, and levator palpebrae superioris (all of the muscles of the orbit except two)
52
What types of fibers are contained within the Oculomotor Nerve (CN III)?
GSE and GVE (from parasympathetics)
53
What one type of fibers is contained within CN IV, CN VI, and CN XII?
GSE
54
What single muscle is supplied by the Trochlear Nerve (CN IV)?
superior oblique (abducts, depresses, and internally rotates the eye)
55
The lateral rectus, or the abductor of the eye, is supplied by what cranial nerve?
Abducens Nerve (CN VI)
56
The tongue muscles, except for the palatoglossus are derived from segmented occipital myotomes and supplied by which nerve? What type of fiber does this nerve carry?
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Hypoglossal Nerve (CN XII)
General Somatic Efferent (GSE)
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57
The external ectodermal layer of each branchial arch is supplied by a ______ nerve, the mesodermally derived cartilage and branchial muscle by ______ fibers, and the endodermal mucosa by either ______ or ____ components.
General Somatic Afferent (GSA)
Special Visceral Efferent (SVE)
General or Special Visceral Afferent (GVA or SVA)
58
What five nerves comprise the branchiomeric nerves?
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Trigeminal Nerve (CN V)
Facial Nerve (CN VII)
Glossopharyngeal Nerve (CN IX)
Vagus Nerve (CN X)
Spinal Accessory Nerve (CN XI)
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59
The _____ division of the Trigeminal Nerve is the (sensory) pre-trematic and the _____ division of this nerve is the (mixed) post-trematic division of the branchiomeric nerve to the first gill arch.
Maxillary (V2)
| Mandibular (V3)
60
The opthalmic division of the Trigeminal Nerve (CN V) is also known as the ______. The maxillary division is also known as the ______ and the mandibular division is also known as the _______.
Profundus sensory nerve
Pre-trematic sensory
Post-trematic mixed
61
What nerve innervates all muscles involved in chewing or mastication and muscles that form the floor of the mouth?
Mandibular Division of Trigeminal Nerve (CN V3)
62
What disease is associated with an artery compressing the Trigeminal Nerve and its branches?
Trigeminal neuralgia
63
What two fibers are contained within the Trigeminal Nerve (CN V) and its branches?
SVE- Branchial MM. - 1st Arch
| GSA- General Somatic Sensation
64
What four fibers are contained within the Facial Nerves (CN VII)?
SVE- Branchial MM- 2nd Arch
GSA- General Somatic Sensation
GVE- Parasympathetic Fibers
SVA- Taste, Anterior 2/3 of tongue
65
What type of fiber is contained within all of the branchiomeric nerves?
Special Visceral Efferent Fibers (SVE), which are associated with each respective branchial arch
66
What nerve carries Special Visceral Afferent information for the anterior 2/3 of the tongue?
Chorda tympani (of CN VII)
67
What nerve is a branch of the mandibular division of the Trigeminal Nerve (CN V3), which supplies general sensory information to the anterior 2/3 of the tongue?
Lingual nerve
68
What nerve is the largest branch of the Opthalmic division of the fifth cranial nerve (CN V1) and conveys sensory information for the skin of the upper eyelids, forehead, and sides of the nose?
Frontal Nerve
69
The Opthalmic division of the Trigeminal Nerve (V1) is formed by the union of which three nerves?
Lacrimal, Nasociliary, and Frontal Nerves
70
What nerve branches from the Facial Nerve (CN VII) and forms part of a chain of nerves that innervates the lacrimal gland?
Greater Petrosal Nerve
71
What branch of the Facial Nerve (CN VII) originates from the taste buds in front of the tongue, runs through the middle ear, and carries taste messages to the brain?
Chorda tympani
72
Describes the extracranial distribution of CN VII.
Temporal, Zygomatic, Buccal, Mandibular, and Cervical (from superior to inferior)
73
What disease results in weakness of the orbicularis oculi and of the retractors of the angle of the mouth?
Bell's Palsy
74
Describe the five fibers contained in the Glossopharyngeal Nerve (CN IX).
```
SVE- Branchial MM- 3rd arch
GVE- General Visceral Sensation (Pharynx)
GVE- Parasympathetic Fibers
GSA- General Somatic Sensation (Oracle)
SVA- Taste (Epiglottis)
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75
What term describes the nucleus of the Spinal Accessory Nerve (containing Special Visceral Efferents to the derivatives of the 5th and 6th arches)?
Nucleus ambiguus in the medula
76
The fibers of the cranial root of the Spinal Accessory Nerve are distributed by the _____ nerve.
Vagus
77
The "spinal root" fibers of the Spinal Accessory Nerve ascend through the _____ to lie next to the "cranial root" in the ______ before exiting to descend external to the _____ and innervate portions of the trapezius and sternocleidomastoid muscles as the body of the Spinal Accessory Nerve (CN IX)- GSE fibers.
Foramen Magnum
Jugular fossa
Jugular foramen
78
What two fibers are contained within the Spinal Accessory Nerve (CN IX)?
SVE- Cranial Portion- Branchial MM- 5th-6th Arch
| GSE- Spinal Portion
79
What six nerves provide auricular sensation?
CN V- Auriculotemporal Branch
CN VII- Small area, posterior cranial wall
CN IX- Medial, inner part of the tympanic membrane
CN X- Most of the ear canal and part of the outer surface of the tympanic membrane
Greater Auricular Nerve- C2, C3
Lesser Occipital Nerve- C2
80
What are the three types of ganglia found in the head and neck?
Autonomic (Sympathetic)
Autonomic (Parasympathetic)
Sensory
81
What is the ganglion of the Trigeminal Nerve (CN V)?
Trigeminal (semilunar) ganglion
82
What is the ganglion of the Facial Nerve (CN VII)?
Geniculate ganglion
83
What are the two ganglia of the Vestibulo-Cochlear Nerve (CN VIII)?
Vestibular ganglion
| Cochlear (spiral) ganglion
84
Superior and inferior glossopharyngeal ganglion is to ______ and superior (jugular) and inferior (nodose) ganglia are to _____.
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Glossopharyngeal Nerve (CN IX)
Vagus Nerve (CN X)
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