Cranial nerves
How is the right optic tract different from the left optic tract
Left: contains neurons from the temporal half of the left retina and the nasal half of the right retina
what is Horner's syndrome
what are signs observed on the ipsilateral side
1) a season of the sympathetic trunk. caused by damage to the sympathetic innervation to the head
2)
ptosis:_____________
anhidrosis:___________
miosis:______________
what is hyperacusis?
a lesion of CN VII may cause paralysis of the stapedius muscle resulting in a wider oscillation of the stapes
the nasal cavity receives innervation from what cranial nerves
CN 1, V-1, V-2, VII
what are the 3 regions of the pharynx in order from top to bottom
nasopharynx
oropharynx
laryngopharynx
a complete cavernous sinus lesion disrupts ____________ and causes _____________, usually accompanied by a fixed ______________.
a complete cavernous sinus lesion disrupts __CN III, IV, VI__ and causes __total ophthalmoplegia__, usually accompanied by a fixed __a fixed dilated pupil___.
what are the three main muscles of the eyelid and what innervates them (what cranial nerves)
orbicularis oculi muscle: circular muscle that closes the eye = CN VII
levator palpeerde superioris muscle: skeletal muscle that elevates the upper eye lid = CN III
superior tarsal (Müller's) muscle: smooth muscle that elevates the eye lid // attaches between the levator palpebral superiors muscle and the upper eyelid = innervated by sympathetic nerves
what are the 3 layers of the tympanic membrane composed?
what cranial nerves pass through the TM
outer =skin layer
middle = fibrous layer (CNVII)
inner = mucosa layer (CN IX)
what are the 3 meatus and what do they open for
side not apart of question but did not have space for it to be its own question : how do you diagnose rhinorrhea?
superior meatus: the posterior ethmoidal air cells
middle meatus : the frontal sinus via the n'as-frontal duct
inferior meatus: nasolacrimal duct: drains tears from the eye into the nasal cavity
measure beta 2 transferrin
does the sympathetic or parasympathetic division control salivation
what in that division stimulates the glands
both
para: cholinergic parasympathetic fibers
symp: B-adrenergic stimulation from sympathetic fibers
Name the three divisions of the trigeminal ganglion and what does each one provide
CN V-1 ophthalmic: general sensory innervation to the orbit, cornea and skin of the bridge of the nose, anterior scalp, and forehead
CN V-2 maxillary: general sensory innervation to the skin between the lateral corners of the eye and the corners of the mouth/ also/ general sensory innervation to the palate, nasal cavity, paranasal sinuses, and maxillary teeth and gums
CN V-3 mandibular: a) general sensory innervation to the lower part of the face including the anterior two-thirds of the tongue, the mandibular teeth, the mandibular face and part of the scalp/ b) motor division : innervates muscles of mastication
what are the 6 muscles involved in extra ocular muscle movement?
what cranial nerve are they under?
in what direction does the eye move when each muscle contract?
- superior rectus muscle (CN III): elevation of the eye, with adduction and intorsion
- inferior rectus muscle (CN III) depression of the eye with adduction and extortion
-lateral rectus muscle (CN VI) the only action is the abduction of the eye
-medial rectus muscle (CN III) the only action is the adduction of the eye
-superior oblique muscle (IV) moves the eye ball down and out (depression and abduction) with intrusion
- inferior oblique muscle ( CN III) moves the eyeball up and out (elevation and abduction) with extortion
where are the other two names of the auditory tube?
what muscle Is attached to it?
the auditory tube receives general sensory innervation from CN ___
when is it open and when is it closed?
Eustachian or pharyngotympanic tube
tensor tympani muscle
CN IX
normally collapsed but yawning or swallowing can open the tube
what are the 4 paranasal sinuses?
what are they used for?
what would they look like on an x-ray
know why the maxillary sinusitis is so different and important.
1) ethmoid, frontal, maxillary, sphenoid
2) they help decrease the weight of the skull, resonate sound produced through speech, and produce mucus
3) dark shadows because they are filled with air
what are the 3 pairs of salivary glands?
how much saliva do they secrete in a day
what makes up saliva
lost of saliva can lead to _______ _________
absence of saliva:_________
submandibular, sublingual, and parotid
1L per day
water, mucus, sodium, bicarbonate, chloride, potassium, a-amylase, mucin, IgA, exogenous fluoride
potassium depletion
xerostomia
name the cranial nerves in order and there specific sensory and/or motor controls (ex: special sensory, somatic & visceral motor)
CN 1: olfactory - special sensory
CN 2: optic - special sensory
CN 3: oculomotor - somatic and visceral motor
CN 4: trochlear - somatic
CN 5: trigeminal - general sensory and branchial motor
CN 6: abducens - somatic motor
CN 7: facial - motor, special, and visceral sensory
CN 8: vestibulocochlear -special sensory
CN 9: glossopharyngeal -motor, special, visceral sensory
CN 10: vagal - visceral sensory
CN 11: accessory - branchial motor
CN 12: hypoglossal - somatic motor
define each and explain the etiology
presbyopia
myopia
hyperopia
astigmatism
cataract
glaucoma
macular degeneration
presbyopia- when you get older the ocular lens becomes larger , firmer and less elastic = loss of accommodation
myopia- nearsightedness = light focuses in front of the retina = increased distance between the retina and the lens
hyperopia- farsightedness = light focuses behind the retina = shortened distance between the retina and the lens
astigmatism refractive error due to rotational asymmetry in the eye's refractive power
Cataract= loss of transparency of the lens due to excessive connective tissue
glaucoma = optic nerve is damaged = increased fluid pressure in the eye due to dysfunction of the scheme canal
macular degeneration= macula is responsible for central, high resolution, color vision so damage to the macula leads to central blurry vision.
what are the 3 chambers of the cochlea?
where do they stop and end?
what fluid do they contain?
scala vestiboli: upper chamber// begins at the vestibular window and is continuous with vestibule// contains perilymph
scala tympani: lower chamber // terminates at the cochlear window // contains perilymph
scala media (cochlear duct): middle chamber roof: vestibular membrane, floor: basilar membrane/filled with endolymph // ends at helicotrema //// houses spiral organ (organ of corti)
what do the following nerves do for the nose
CN 1
CN V-1
CN V-2
CN VII
CN 1: special sensation for smell
CN V-1: general sensation to the superior aspect of the nasal cavity
CN V-2: general sensation to most of the nasal cavity
CN VII: parasympathetic innervation to the nasal glands
what are the 3 accessory pharyngeal muscles?
what are their actions
what are their innervation
stylopharyngeus: elevates the pharynx to permit passage of a bolus of food// innervated by CN IX
palatopharyngeus muscle: contraction pulls the pharynx upward and over the bolus of food during swallowing// innervated by CN X
salpingopharyngeus muscle: widens the opening of the pharyngotympanic tube during swallowing, which equalizes the pressure between the auditory canal and the nasopharynx// innervated by CN X
where does each cranial nerve originate
CN 1: originates in the olfactory epithelium in the superior part of the lateral and septal walls of the nasal cavity // through the cribriform forming of the ethmoid bone
CN 2: is an extension of the forebrain
CN 3: the Edinger Westphal nucleus and the oculomotor nucleus (Edinger synapse to ciliary ganglion) they both enter the eyes through superior orbital fissure
CN 4: only CN that come from the brainstem's dorsal aspect through the cavernous sinus enters orbit via the superior orbital fissure
CN 5: lateral surface of the pons as a large sensory root and a small motor root then inters trigeminal (Meckel's) cave of the dura
CN 6: from the pons and courses through the cavernous sinus enters through the superior orbital fissure
CN 7: did not say
CN 8: originates from the grooves between the pons and the medulla oblongata
CN 9: did not say
CN 10: from the lateral aspect of the medulla oblongata // travels between the internal jugular vein and the internal carotid artery within the carotid sheath
CN 11:Jugular foraman
CN 12: hypoglosses canal
what are the structure and function of the following
-sclera
-cornea
-aqueous humor
-vitreous humor
-suspensory ligaments
-iris
-lens
-ciliary body
-choroid
-retina
-optic nerve
-fovea
-blind spot
-rods
-cones
use slides
to much to type
how do we hear
1) the external ear collects sound waves and transports them through the external meatus to the tympanic membrane
2) the tympanic membrane vibrates, setting three tiny ear ossicles in the middle ear into motion
3) the stapes attach to the lateral wall of the inner ear, where the vibration is transducer into fluid movement
4) the fluid causes the basilar membrane in the cochlea to vibrate
5) the vestibulocochlear nerve receives and conducts the impulses to the brain, where there is the integration of sound and equilibrium
what are the 5 main tastes
bitter
salty
sweet
sour
umami
what are the stages of swallowing?
last one
what cranial nerves are assigned to each part of the pharynx
1 tongue pushes back food back toward oropharynx
2 palatoglossus and palatopharyngeus muscles contract to squeeze the food backward into oropharynx
3 tensor veli palatini and levator veli palatini muscles elevate and tense the soften palate to close the entrance to the nasopharynx
4 the palatopharyngeus, stylopharyngess and salpingopharyngeus muscles elevate the walls of the pharynx in preparation to receive the food
5 supra hyoid muscles elevate the hyoid bone and larynx to close the opening into the larynx, thus preventing the food from entering the respiratory passageway
6 the sequential contraction of the superior, middle, and inferior pharyngeal constrictor muscles moves the food through the oropharynx and laryngopharynx into the esophagus via peristalsis
nasopharynx-CN V-2
oropharynx CN IX
laryngopharynx _CN X