Head 2 Flashcards
where is the posterior cavity of the eye and what is in it
behind lens
has vitreous humor
what is the function of vitreous humor
presses retina against choroid and helps maintain eyeball shape
important for forensics because can be drawn to find chemicals
explain the features of glaucoma
aqueous humor fluid builds up which raises pressure to compress and damage retina and optic nerve
eventually can cause blindness
cause is usually unknown
what is the arterial flow of the orbit
internal carotid artery, ophthalmic artery, short posterior ciliary artery, central retinal artery, lacrimal artery, lacrimal gland
what is the purpose of the short posterior ciliary artery
artery near optic disc
supplies choroid and outer later of retina
what is the purpose of the central retinal artery
enters eye with optic disc structures
supplies internal surface of retina
what is the venous flow of the orbit
vortex veins to superior and inferior ophthalmic veins to cavernous sinus
where is light refracted
lens and cornea
what are errors of refraction
lens can not round up either to aging or shape of eye ball
division which includes myopia (nearsightedness), presbyopia (farsightedness), and astigmatism
what near point of accommodation
closest point at which eye can focus on an object
gets longer as you age
what is presbyopia
condition where someones near point of accommodation is greater than 25 cm (farsightedness)
what causes nearsightedness (myopia) and how is it fixed
eyeball is too long so lens can’t flatten enough so the image focuses in front of the retina
use concave lenses
what is an astigmatism and how is it fixed
irregular curvature of cornea or lens which causes rays of light to not be evenly refracted
causes blurriness that can be fixes with corrective lenses
what part of the body is associated with vestibular sense
ear
what do ceruminous glands do
secrete cerumen (ear wax) which lubricates and waterproofs canal
1.)
auricle (pinna)
2.)
external auditory canal (external acoustic meatus)
3.)
helix
4.)
antihelix
5.)
antitragus
6.)
tragus
what type of cartilage is the outer ear made out of
elastic cartilage
what is the tympanic cavity or middle ear
hollow, air-filled mucous membrane-lined chamber found in the temporal bone
begins at the tympanic membrane and ends at the inner ear
contains three auditory ossicles
what are the three auditory ossicles and what do they do
malleus, incus, and stapes
amplify and convert incoming sound waves in air into fluid movement
explain features of otitis media
inflammation of middle ear
common in children due to upper respiratory infections
acute otitis media (AOM) - when pharyngotympanic tube allows pathogens from nasopharynx to travel into middle ear - tube is more short and horizontal
usually treated with antibiotics or tubes
explain features of otosclerosis
ossicles fuse which prevents sound from traveling from middle to inner eat
can be inherited or come from an infection
1.)
malleus
2.)
incus
3.)
stapes
4.)
round window (cochlear window)
5.)
pharyngotympanic tube
6.)
oval window (vestibular window)
what is the cochlea responsible for
hearing
what are the vestibule and semicircular canals responsible for
detect head movement and position
what nerves run through the internal acoustic meatus
CN 7 (facial) and 8 (vestibulocochlear)
what are maculae
sensory epithelium in vestibule that have otolith
convey stimuli about head tilt and linear movement
what does the crista ampullari do
has receptor cells that detect rotational movement
what does endolymph do
transduces sound waves and head movements into electrical signals
1.)
semicircular canals
2.)
vestibule
3.)
utricle
4.)
saccule
5.)
cochlea
6.)
cristae ampullari
7.)
maculae
8.)
spiral organ
explain features of benign paroxysmal positional vertigo (BPPV)
calcium carbonate (otoliths) separated from normal attachments in inner ear
float in endolymph in crista ampullari
they can stimulate balance mechanism and cause feeling of spinning
primary and secondary types
primary: unknown cause
secondary: head trauma
