Cranial Nerves Flashcards
How many cranial nerves are there?
12
Name the cranial nerves in order.
Olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, vestibulocochlear, glossopharayngeal, vagus, spinal accessory, hypoglossal
What are the 7 functional components?
SVA (special visceral afferent) SVE (special viseral efferent) SSA (special somatic afferent) GVA (general visceral afferent) GVE (general visceral efferent) GSA (general somatic afferent) GSE (general somatic efferent)
What does SVA fibers do?
Special visceral afferent: taste & smell
What does SVE fibers do?
Special visceral efferent: motor to the muscles of pharyngeal arch origin
What does SSA fibers do?
Special somatic afferent: sight, hearing, & balance
What does GVA fibers do?
General visceral afferent: sensory from the viscera (such as pain and temperature)
What does GVE fibers do?
General visceral efferent: motor of the parasympathetic nervous system, pre-ganglionic fibers, & post-ganglionic fibers
What does GSA fibers do?
General somatic afferent: proprioception from muscles and joints & skin tactile sensation
What does GSE fibers do?
General somatic efferent: motor to voluntary muscles
How many function components are there for CN 1?
1–SVA fibers that synapse in the olfactory bulb
Where does CN 1 exit the skull?
Cribiform plate
How many function components are there for CN 2?
1–SSA fibers that provide sensory from the retina
Where does CN 2 exit the skull?
Optic canal
How many function components are there for CN 3?
2–GVE and GSE
What does the GVE component of CN 3 do?
Presynaptic fibers synapse with the cillary ganglion (that sits on top of optic nerve) and post synaptic fibers innervate the constrictor pupil muscle and the ciliary body of the lens
What does the GSE component of CN 3 do?
Innervates 5 of the extraoccular eye muscles: levator palpebrae superioris, superior rectus, medial rectus, inferior rectus, and inferior oblique
Where does CN 3 exit the skull?
Superior orbital fissure
How many function components are there for CN 4?
1–GSE fibers innervate the superior oblique muscle.
Where does CN 4 exit the skull?
Superior oribital fissue
What are the three components of CN 5?
V1 (sensory), V2 (sensory), and V3 (sensory and motor)
Where does V1 exit the skull?
Superior orbital fissure
Where does V2 exit the skull?
Foramen rotunda
Where does V3 exit the skull?
Foramen ovale
How many function components are there for V1 of CN 5?
1–GSA fibers that provide sensory from the nasal and frontal region
How many function components are there for V2 of CN 5?
1–GSA fibers that provide sensory form the maxillary region
How many function components are there for V3 of CN 5?
2–SVE and GSA
What does the SVE fibers of V3 from CN 5 innervate?
The muscles of mastication + 4 (two T’s and two others)
Muscles of mastication= masseter, temporalis, medial & lateral ptygeroids
+4= Tensor veli palatini
Tensor tympani
Anterior belly digastric
Mylohyoid
What does the GSA fibers of V3 from CN 5 innervate?
GSA fibers provide sensory from the mandibular region of the face
How many function components are there for CN 6?
1–GSE fibers that innervate the lateral rectus eye muscle
Where does CN 6 exit the skull?
Superior orbital fissure
How many function components are there for CN 7?
5–SVA, SVE, GVA, GVE, and GSA
Which of the cranial nerves have 5 functional components? What are they?
CN 7, 9, and 10
SVA, SVE, GVA, GVE, and GSA
What does the SVA component of CN 7 do?
Provides taste from the anterior 2/3 of the tongue
What does the SVE component of CN 7 do?
Innervate pharayngeal arch 2 muscles Innervate muscles of facial expression + 4 (2 S's & 2 P's) \+4= stylohyoid stapedius platysma posterior belly digastric
What does the GVA component of CN 7 do?
Provides sensation from the deep face
What does the GVE component of CN 7 do?
Provides motor to the salviary glands (submandibular and sublingual), lacrimal gland, and two ganglia (sphenopalatine and submandibular ganglion)
What does the GSA component of CN 7 do?
Provides sensory from the external pinna of the ear
Where does CN 7 exit the skull?
It first enters the internal auditory meatus and then exits the stylomastoid foramen
How many functional components are there for CN 8? What is it for?
1- SSA fibers for hearing and balance from the cochlea and vestibular apparatuses
Where does CN 8 exit the skull?
It enters the internal acoustic meatus, but does NOT exit the skull
How many function components are there for CN 9? What are they?
5– SVA, SVE, GVA, GVE, and GSA
What does the SVA component of CN 9 do?
Provides taste from the posterior 1/3 of the tongue
What does the SVE component of CN 9 do?
Provides motor innervation to the pharayngeal arch #3 muscle: stylopharyngeus
What does the GVA component of CN 9 do?
Provides general sensation from the back of the mouth, oral cavity, and posterior 1/3 of the tongue. It also provides sensory to the chemoreceptors from the carotid body (pCO2)
What does the GVE component of CN 9 do?
Provides innervation to the parotid salivary gland (and these fibers synapse in the otic ganglia)
What does the GSA component of CN 9 do?
Provides sensory to the external pinnae of the ear
Where does CN 9 exit the skull?
Jugular foramen
How many functional components does CN 10 have? What are they?
5– SVA, SVE, GVA, GVE, and GSA
What does the SVA component of CN 10 do?
Provides sensation to the taste buds of the epiglottis
What does the SVE component of CN 10 do?
Provides motor innervation to the muscles of pharayngeal arches 4 & 6; the muscles of teh larynx, pharynx, and soft palate; and the palatoglossus and glossopharyngeus muscles
What does the GVA component of CN 10 do?
Provides sensory from the larynx, pharynx, soft palate, foregut, midgut, and baroreceptors in the aortic arch and atrial wall
What does the GVE component of CN 10 do?
Innervates the foregut (synapse in the enteric ganglia), lie in the walls of organs, long preganglionic and short postglangionic fibers, and innervates the heart, lungs, and all the organs of the thorax and upper abdomen
What does the GSA component of CN 10 do?
Provides sensory to the external pinnae of the ear
How many functional components are there for CN 11?
1- SVE
What does the functional component of CN 11 do?
SVE fibers provides motor innervation to the SCM and the trapezius muscles (also C2-3 provides proprioception for the SCM and C3-4 provides proprioception for trapezius)
Where does CN 11 exit the skull?
Jugular foramen
There are pharyngeal arches for CN 11. True or false?
False. There are no pharyngeal arches for CN 11.
How many functional components are there for CN 12? What are they?
1–GSE
What does the functional component of CN 12 do?
GSE fibers provide motor innervation to the intrinsic and extrinsic tounge muscles (genioglossus, hyoglossus, and the styloglossus muscles)
Where does CN 12 exit the skull?
Hypoglossal foramen