19B (Vision & Hearing) Flashcards
these muscles are on the external eye
extrinsic muscles
these close to spread tears
eyelids
inner corner of eye
medial canthus
outer corner of eye
lateral canthus
fleshy portion of eye
lacrimal caruncle
lining of the eyelids & over the anterior surface of eye, does not cover cornea
conjunctiva
this structure produces, collects and drains tears from the eye
lacrimal apparatus
this produces tears
lacrimal gland
this collects tears
lacrimal sac
this is where excess tears drain
lacrimal canaliculi
this is where tears drain through nasal cavity
nasolacrimal duct
this is in front of the lens and contains circulating aqueous humor
anterior cavity
this is behind the lens and contains permanent vitreous humor
posterior cavity
name the three eye wall layers
fibrous tunic, vascular tunic, retina
what does the fibrous tunic contain?
sclera and cornea
what does the vascular tunic contain?
iris, ciliary body, choroid
what layers does the retina have?
a pigmented layer and a neural layer
this condition is the result is increased inner eye pressure
glaucoma
transparent layer of the eye
cornea
white of the eye, provides shape and protects internal eye
sclera
contains vast network of capillaries supplying nutrients and oxygen to the retina
choroid
changes the lens shape
ciliary body
this is the pigmented part of the anterior eye, controls the amount of light that enters eye
iris
name the two types of pupillae
sphincter and dilator (allows more light in)
the internal layer of the eye
retina
this layer of the retina houses photoreceptors and converts energy into nerve impulses
neural layer
name the three distinct layers from the neural layer
photoreceptor cells, bipolar cells, ganglion cells
this is the outermost neural layer composed of rods & cones
photoreceptor cells
this neural layer synapses photoreceptor & ganglion cells
bipolar cells
innermost neural layer, axons of these cells leave the retina and form the optic nerve
ganglion cells
characteristics of rods
more rods than cones, numerous in the periphery, night vision, low acuity, vision in shades of gray
characteristics of cones
less cones than rods, concentrated in fovea, day vision high acuity, color vision
this is a blind spot on the retina lacking photoreceptors
optic disc
a depression in the retina containing the highest proportion of cones & no rods, sharpest vision
fovea centralis
where is the fovea centralis located?
within the macula lutea
this is a transparent structure of the eye
the lens
accommodation
ability of the lens to change shape to focus an image
the ability to distinguish fine detail
visual acuity
someone with 20/20 vision is considered
normal
someone with 20/ <20 has vision considered
better than normal
someone with 20/ >20 has vision considered
worse than normal
inability to focus on objects that are far
myopia
what is the cause of myopia?
eyeball is too long–focuses in front of fovea
what can fix myopia?
lenses that add width to the eye
inability to focus on objects that are close
hyperopia
what is the cause of hyperopia?
eyeball is too short
what can fix hyperopia?
lenses that add length to the eye
this condition is an increase in farsightedness with age
presbyopia
this condition is irregularity on surface of cornea or lens, light will scatter
astigmatism
this condition is inflammation of the conjunctiva
conjunctivitis or pinkeye
the condition is the clouding of the lens
cataracts
this condition has small unstable blood vessel developing along the retina and will cause blindspots if ruptured
diabetic retinopathy
this condition is the misalignment of the eyes
strabismus
name the 3 distinct regions of the ear
external, middle, inner ear
name the parts of the external ear
auricle, external acoustic meatus, tympanic membrane (eardrum)
within the external acoustic meatus, glands will product what?
cerumen/earwax
name the parts of the middle ear
auditory tube, auditory ossicles
connects middle ear to nasopharynx
auditory tube
these are small bones are transmit sound waves to inner ear
malleus, incus, stapes
what parts make up the equilibrium portion of the inner ear?
utricle, saccule, semicircular glands
what part makes up the hearing portion of the inner ear?
the cochlea
what parts of the inner ear detects static equilibrium?
utricle & saccule
what part of the inner ear detects dynamic equilibrium?
semicircular ducts
when hair cells bend, electrical activity is sent to the brain via the ______
vestibular nerve
there are three semicircular canals, and each have an expanded region called ____
the ampulla
this is an elevated region of ampulla covered by an epithelium of hair cells
crista ampullaris
the hair cells embed into an overlying gelatinous dome is called the _____
capula
within the cochlea is the ______, filled w/ endolymph
cochlear duct
on either side of the cochlea duct are two chambers filled with perilympth
scala vestibuli & tympani
_____ of cochlea contain hair cells, which have extensions projecting into an overlying gelatinous mass called the _____
spiral organ, tectorial membrane
____ interprets sensory impulses
temporal lobe
sound waves of various frequencies stimulate different parts of basilar membrane
pitch discrimination
louder sound sources cause tympanic membrane to vibrate more in & out
loudness discrimination
this condition is ringing in the airs
tinnitis
this condition is caused by fluid buildup in the middle ear
conductive hearing loss
this condition is an ear infection at either of the 3 distinct regions
otitis