Cranial Nerves Flashcards
(45 cards)
1
Q
describe directional terminology for the forebrain
A
- rostral - anterior
- dorsal - superior
- caudal - posterior
- ventral - inferior
2
Q
describe directional terminology for the brainstem and spinal cord
A
- rostral - superior
- caudal - inferior
- ventral - anterior
- dorsal - posterior
3
Q
names of cranial nerves I-XII
A
- CN I - olfactory n.
- CN II - optic n.
- CN III - oculomotor n.
- CN IV - trochlear n.
- CN V - trigeminal n.
- CN VI - abducens n.
- CN VII - facial n.
- CN VIII - vestibulocochlear n.
- CN IX - glossopharyngeal n.
- CN X - vagus n.
- CN XI - accessory n.
- CN XII - hypoglossal n.
4
Q
describe general somatic afferents of cranial nerves
A
- somatic sensation
- fibers convey impulses from the skin and striated muscle spindles
5
Q
describe general visceral afferents of cranial nerves
A
- visceral sensation
- fibers convey impulses from the viscera and blood vessels
6
Q
describe general visceral efferents of cranial nerves
A
- visceromotor function
- fibers innervate the smooth muscle of the viscera, intraocular muscles, heart, salivary glands, etc.
7
Q
describe general somatic efferents of cranial nerves
A
- somatomotor function
- fibers innervate striated muscles
8
Q
describe special somatic afferents of cranial nerves
A
- fibers conduct impulses from the retina and from the auditory and vestibular apparatus
9
Q
describe special visceral afferents of cranial nerves
A
- fibers conduct impulses from the taste buds of the tongue and from the olfactory mucosa
10
Q
describe special visceral efferents of cranial nerves
A
- fibers innervate striated muscles derived from the branchial arches (branchiogenic efferents and branchiogenic muscles)
11
Q
describe CN I
A
- olfactory n.
- special sensory
- only sensory
- part of the telencephalon, NOT a true cranial nerve
- true olfactory fibers run from olfactory epithelium in the nasal cavity through cribriform plate and innervate the olfactory bulb
12
Q
describe CN II
A
- optic nerve
- special sensory
- only sensory
- part of the diencephalon, NOT a true cranial n.
- some fibers cross, others do not, at the optic chiasm
- fibers then run in the optic tract
- leaves the orbit via the optic canal
13
Q
describe CN III
A
- oculomotor nerve
- somatic motor control - superior rectus m., inferior rectus m., medial rectus m., and inferior oblique m.
- upper eyelid - levator palpebrae superioris
- visceral motor control - pupillary constrictors, pupillary sphincter, ciliary muscle
- enters orbit via superior orbital fissure
14
Q
describe CN IV
A
- trochlear n.
- somatic motor control - superior oblique
- enters orbit via superior orbital fissure
- only CN with contralateral symptoms in nuclear lesion (still ipsilateral in nerve lesion)
- only CN to emerge from dorsal surface
15
Q
describe CN VI
A
- abducens n.
- somatic motor control - lateral rectus m.
- pulls the eye away from the midline (abduction of the eye)
16
Q
which 3 cranial nerves control ocular muscles?
A
- CN III, IV, and VI
17
Q
describe CN V
A
- trigeminal n.
- emerges in the middle of the pons
- trigemical ganglion
- 3 branches: V1 - ophthalmic, V2 - maxillary, V3 - mandibular
- innervates: muscles of mastication, oral floor muscles, tensor tympani (middle ear), tensor veli palatini (pharyngeal)
- sensation of the face, forehead, and tongue
- branches of other cranial nerves join up with CN V
18
Q
describe the general sensory innervation of CN V
A
- ophthalmic division (V1)
- trigeminal ganglion
- maxillary division (V2)
- mandibular division (V3)
- skin of the face, nasal mucosa, and anterior 2/3 of the tongue
19
Q
describe the general motor innervation of CN V
A
muscles of mastication:
- temporalis
- maseter
- medial pterygoid
- lateral pterygoid
20
Q
describe the visceral hitchhikers of CN V
A
- branches of CN VII hitchhike on V2 and V3 nerves to get to glands in the face
- branch of CN IX hitchhikes on V3 / posterior auricular to get to parotid gland
21
Q
describe ophthalmic division of CN V
A
- V1
- exits through the superior orbital fissure
- frontal n.
- nasociliary n.
- lacrimal n. (sensory only)
22
Q
describe the maxillary division of CN V
A
- V2
- exits via the foramen rotundum
- posterior, middle, anterior superior alveolar nn.
- infraorbital n.
- zygomatic n.
23
Q
describe the mandibular division of CN V
A
- V3
- exits via the foramen ovale
- auriculotemporal n.
- buccal n.
- pterygoid branch
- masseteric branch
- inferior alveolar n.
- lingual n.
24
Q
which 3 nerves penetrate the foramen ovale?
A
- auriculotemporal n.
- inferior alveolar n.
- lingual n.
25
what are the features of the lingual n.?
* runs medial to the mandible
* branch of V3
* general sensory - mucosa, 2/3 of tongue, and floor of mouth
* chorda tympani
26
describe the chorda tympani
* branch of CN VII
* runs with lingual n.
* innervates glands (submandibular, sublingual, sm ones)
* taste, anterior 2/3 of tongue
27
what are the features of the inferior alveolar n.?
* part of the mandibular division (V3) of CN V
* runs within the mandible, enters mandibular foramen
* mylohyoid, anterior belly of digastric (motor)
* pulp of teeth (sensory)
* mental n. - skin and lip (sensory)
28
what are the 5 branches of CN VII that innervates muscles of facial expression?
* temporal
* zygomatic
* buccal
* cervical
* posterior auricular
29
what is the greater petrosal n.?
* branch of CN VII that innervates lacrimal and nasal glands
30
what is the nerve to stapedius?
* branch of CN VII that innervates the stapedius m.
* branches that innervate stylohyoid and posterior belly of digastric
31
describe CN VIII
* vestibulocochlear n.
* special sensory n. only, but 2 different modalities: vestibular senses and sense of hearing
32
describe CN IX
* glossopharyngeal n.
* exits via jugular foramen
33
describe the motor innervation of CN IX
* pharyngeal constrictors
* stylopharyngeus
* parotid gland
34
describe the sensory innervation of CN IX
* posterior tongue
* posterior oral pharynx
* mucosa - middle ear
* skin - external ear, canal
* tympanic membrane
35
describe the special sensory innervatino of CN IX
* taste - posterior 1/3 tongue
* chemoreceptors and baroreceptors - carotid sinus
36
describe the sensory innervation of CN X
vagus n.
* visceral in abdomen and thorax
* laryngopharynx and larynx
* taste - epiglottis
* ear and external acoustic meatus
* posterior cranial fossa - dura
37
describe the motor innervation of CN X
vagus n.
* pharyngeal constrictors (with CN IX)
* laryngeal mm.
38
describe the special sensory innervation of CN X
vagus n.
* pressure receptors - aortic arch
* chemoreceptors - aortic body
39
describe CN XI
* spinal accessory n.
* innervates SCM and trapezius mm
* ascends cord, into skull via foramen magnum, exits with CN X via jugular foramen
40
what motor deficits are associated with CN XI impingement?
* will not be able to contract muscles (trapezius and SCM)
41
describe CN XII
* hypoglossal n.
* motor only
* tongue muscles
* exits via hypoglossal canal
42
which cranial nerves are motor only?
* CN III - oculomotor n
* CN IV - trochlear n.
* CN VI - abducens n.
* CN XI - accessory n.
* CN XII - hypoglossal n.
43
which cranial nerves are sensory only?
* CN I - olfactory n.
* CN II - optic n.
* CN VIII - vestibulocochlear
44
which cranial nerves are both sensory AND motor?
* CN V - trigeminal n.
* CN VII - facial n.
* CN IX - glossopharyngeal n.
* CN X - vagus n.
45
describe the relationship between location (dorsal/ventral) of cranial nerves and their modality (sensory vs. motor)
* more dorsal (lateral) nerves are sensory
* more ventral (medial) nerves are motor
