cranial nerves Flashcards
cranial nerves can contain
sensory or motor fibers
motor fibers (efferent)
- somatic motor: to striated muscles in the orbit, tongue and external neck as well as straited muscles of the face, palate, pharynx, and larynx
- branchial motor: muscles of the face, palate, pharynx, and larynx are derived form the pharyngeal arches and their somatic motor innervation
- visceral motor: to glands and involuntary smooth muscle in visceral and blood vessels
sensory fibers (afferent)
-somatic (general sensory): transmit general sensation (touch, pressure, heat, cold)
-visceral (general sensory): convey sensation from viscera (carotid body and sinus, pharynx, and trachea)
-special sensory: convey taste, smell, hearing, vision, and balance
- Olfactory Nerve : CN I
component
special sense
exit
-component: smell from nasal cavity
-special sense: smell from nasal cavity
-exit: cribriform plate of the ethmoid bone
- optic nerve CN II
component:
special sense
exit
component; sensory
special sense: sight from retina
-has optic chiasm: right and left tracts of fibers merge, allows field of vision to cross
exit: optic canals from the sphenoid bone
- Occulomotor nerve CN III
component: motor
somatic motor:
visceral motor
exit
component: motor
somatic motor: extraocular muscles
visceral motor: (pre-synaptic parasympathetic) constricts the pupil and accommodate the lens
exit: superior orbital fissure of the sphenoid bone
- trochlear nerve CN IV
component:
somatic motor
exit
component: motor
somatic motor: superior oblique muscles
exit: superior orbital fissure of the sphenoid
- trigeminal nerve CN V
component:
sensory and motor
- trigeminal nerve CN V1: opthalmic division
component: general sensory:
exit
component: general sensory, from the skin of the forehead, external nose, phitrum of upper lips
exit: supraorbital fissure
- trigeminal nerve CN V2: maxillary divison
component: general sensory:
exit
component: general sensory: from skin of the face overlying the maxilla, nasal cavity, upper teeth, and palate
exit: foramen rotundum
- trigeminal nerve CN V3: mandibular division
components
generally sensory
branchial/somatic motor
exit
components: sensory and motor
generally sensory: from skin over the mandible, lower lip, an TMJ
branchial/somatic motor: muscles of mastication
exit: foramen ovale
- abducent nerve CN VI
component
somatic motor
exit
component: motor
somatic motor: to lateral rectus muscle
exit: superior orbital fissure of sphenoid
- facial nerve CN VII
components:
special sensory
branchial motor and exit
visceral motor
common meet
component: sensory and motor
special sensory: taste, from the 2/3rds of the tongue
branchial motor: muscles of facial expression
-exit: stylomastoid foramen
visceral motor: lacrimal gland, nasal, and palatine mucosal glands, submandibular and sublingual glands
exit route meet: internal acoustic meatus
facial expression muscles
-temporal, zygomatic, buccal, mandibular, cerivical
-pass through parotid gland
-insert: facial nerve
- vestibulocochlear nerve CN VIII
component:
special sensory
exit
component: sensory
special sensory: hearing and equilibrium from inner ear
exit: internal acoustic meatus to reach the vestibular system (balance) and cochlea (hearing) of the inner ear
-2 separate nerves
- glossopharyngeal nerve CN IX. HAS ALL
component:
branchial motor:
visceral (parasympathetic) motor:
general somatic sensory
special sensory
visceral sensory
exit
component: sensory and motor
branchial motor: muscle of the pharynx (stylopharyngeus)
visceral (parasympathetic) motor: to the parotid gland
general somatic sensory: palatine tonsil, soft palate, posterior 1/3rd of the tongue
special sensory: taste, from the posterior 1/3rd of the tongue
visceral sensory: from the carotid body (chemoreceptor: O2 saturation), and carotid sinus (baroreceptor: blood pressure).
exit: jugular foramen
- vagus nerve: CN X; HAS ALL
components:
branchial motor
visceral motor
general somatic sensory
special sensory
visceral sensory
exit
branchial motor: muscles of the pharynx, larynx, and palate
visceral motor: to thoracic and abdominal organs
general somatic sensory: from the skin posterior to the ear and external auditory canal
special sensory: taste, from the epiglottis to the root of the tongue
visceral sensory: from the inferior pharynx and larynx mucosa, thoracic and abdominal viscera
exit: jugular foramen
-only nerve that exits the neck
- spinal accessory nerve: CN XI
component:
somatic motor:
arise:
exit
component: motor
somatic motor: trapezius and sternocleidomastoid muscles
arise: series of rootlets from the first cervical segments of the spinal cord which enter the skull via foramen magnum
exit: jugular foramen
- hypoglossal nerve: CN XII
component
somatic motor
exit
component: motor
somatic motor: to muscles within the tongue and those that attach to it (styloglossus, hypoglossus, genioglossus) all except paletoglossal muscles
exit: hypoglossal canal
CN III, VII, and IX
synapse in one of 4 head ganglia and innervate the eye, lacrimal gland, nasal mucosa, and salivary glands
CN X
synapse in an intramural ganglion in the wall of the target organ
sacral outflow (S2-4)
through the inferior hypogastric plexus and synapse in a intramural ganglia in the wall of the target organ
cranial nerves 3,7, and 9 synapse on
trigeminal nerve
