CN (2) Flashcards
General somatic efferent neurons supplies what areas?
motor supply to extraocular muscles (CN III, IV, VI), to sternocleidomastoid and trapezius (CN XI), and all intrinsic and most extrinsic muscles of the tongue (CN XII)
General somatic afferent neurons supplies what areas?
sensation from skin of face, mucosae of oral cavity, and meninges of brain
General visceral efferent neurons supplies what areas?
PS motor supply to sphincter pupillae (CN III), glands of nasal and oral cavities (CN VII, IX), and viscera of thorax and abdomen (CN X)
Special somatic afferent neurons supplies what areas?
signals from visual system (CN II) and from auditory and vestibular system (CN VIII)
Special visceral afferent neurons supplies what areas?
signals for special chemical senses of olfaction (CN I) and gustation (CN VII, IX, X)
Special visceral efferent neurons supplies what areas?
motor innervation to striated skeletal muscle derived from branchiomeric arches, includes: muscles of mastication (CN V), facial expression (CN VII), and muscles of pharynx, larynx and esophagus (CN IX and X)
Olfactory nerves are axons of what kind of cell?
bipolar; mitral cells in bulb
Which cells cross at the optic chiasm?
the ganglion cells corresponding to the nasal portion of the retina
Where is the lesion if the visual loss results in bitemporal hemianopia?
optic chiasm
Where is the lesion if the visual loss results in contralateral homonymous hemianopia?
optic tract, optic radiations, or the upper and lower bank of primary visual cortex
Where is the lesion if the visual loss results in contralateral superior quadrantanopia?
lateral optic radiations or lower bank of primary visual cortex
Where is the lesion if the visual loss results in contralateral inferior quadrantanopia?
medial optic radiations or upper bank of primary visual cortex
Where is the lesion if the visual loss results in monocular visual loss?
optic nerve
Where is the lesion if the visual loss results in monocular scrotoma?
retina
What is the pathway of the CNIII fibers?
Edinger-Westphal nucleus, out midbrain in interpeduncular fossa, enter lateral wall of cavernous sinus, traverse superior orbital fissure; ps to ciliary ganglion
Oculomotor nerve lesion results in what?
pupil deviated down & out, dilated pupil regardless of light level, ptosis of the eyelid, & loss of accommodation.
A lesion to CNIV would result in what?
pupil which drifts ups and in, causing diplopia
What is the course of the abducens nerve
emerges ventrally btwn the pons & medulla, enters cavernous sinus where it lies against internal carotid, into orbit through superior orbital fissure.
A lesion of the abducens nerve results in what?
abducens nerve palsy, medial deviation of the pupil. Turning of the head is an attempt to compensate
What is the course of CN V?
exits brain on lateral surface of pons, entering trigeminal ganglion, 3 major branches emerge innervating diff. dermatomes, and exits cranium thru a different site
The facial nerve emerges from where?
cerebello-ponto-medullary angle
Facial nerve receives input from where? send output to where?
ext. auditory meatus, taste fibers from the anterior 2/3 of the tongue (geniculate ganglion); Autonomic fibers to submandibular, sublingual and lacrimal glands (superior salivatory nucleus) (submandibular or pterygopalatine ganglia)
What is the result of facial nerve lesion?
Bell’s Palsy; paresis or paralysis of the face, hyperacusis, loss of tearing, and loss of corneal/blink reflexes
What are the components of the cochlear nerve?
composed of central processes of bipolar neurons in spiral ganglia; peripheral processes of neurons extend to spiral organ for hearing
