Sensory organs anatomy
The outer ear consists of what?
Pinna, antihelix, Concha, Helix, external meatus, tragus antitragus, lobule
Pinna function?
captures sound waves and protects external meatus
External meatus function?
directs sound to tympanic membrane
Tragus function?
Detects sounds from behind
Inner ear consists of ?
auditory canal, mastoid bone, ossicles, vestibular canals, eustachian tube, cochlea, tympanic membrane, vesttibule containing utricle and sacccule
Structures of the middle ear?
tympanic membrane, ossicles, stapes, eustachian tube
tympanic membrane description?
stretches across ear canal where middle ear begins
Name the ossicles of the ear?
malleus, incus and stapes
ossicles description?
vibration of sound waves against tympanic membrane sets bones into motion
Stapes funtion?
Strikes oval window of inner ear
Eustachian tube is located where?
from middle ear to nasopharynx
Eustachian tube function?
equalizes pressure against the tymanic membrane
Inner ear AKA
labyrinth
structures of the inner ear are?
cochlea and vestibule
cochlea function?
Oval window sets fluid in motion here, sense of sound
Vestibule contains what?
vestibular canals, semicircular canal and the utricle and saccule – sense of balance
Eyelids AKA
palpebrae
Lacrimal apparatus function?
Secretes and drains tears from the surface of the eyeball.
What are the two types of muscles of the eye?
extraocular and intraocular
Extraocular muscles are _________?
voluntary
Inferior oblique function?
rotates top of eye away from the nose
Inferior rectus function?
rotates eye downward
lateral rectus function
moves eye outward away from nose
medial rectus function
moves eye inward, towards nose
superior oblique description?
rotates top of eye toward nose
superior rectus function?
moves eye upward
trochlea description?
unique structure that holds superior oblique and limits eye rotation upward and downward
Intraocular muscles consist of?
ciliary and iris
Ciliary muscles are __________?
involuntary
Ciliary muscle description and function?
radial and circular smooth muscle – helps focus lens
Iris function?
regulates size of pupil
The eye is the ONLY organ with what?
both voluntary and involuntary muscles
What are the tissue layers of the inner eye?
fibrous, vascular, inner
Fibrous tissue layer of the inner eye consists of what?
sclerae and cornea
Sclerae description?
white of the eye
Cornea location and description?
anterior of sclerae and covers the iris
Vascular tissue layer of the inner eye consists of ?
Choroid, ciliary body and iris
Choroid of the eye contains what?
blood vessels and melanin
Ciliary body is located where?
between the retina and iris
Ciliary muscle function?
controls lens
What holds the lens in place?
suspensory ligaments
Iris is attached where?
ciliary body
Iris description?
Colored part of the eye
Iris controls what?
pupil
Inner tissue layer of the inner eye consists of what?
retina, optic nerve and retinal blood vessels
Retina description?
intermost coat on back of eyeball
Retina consists of ?
nervous tissue, rods and cones
Retina consists of ?
nervous tissue, rods and cones
Optic nerve is which cranial nerve?
second
Retinal blood vessels function?
important blood supply to retinal surface (fundus)
What are the two cavities of the eye?
Anterior and posterior
Anterior cavity consists of what?
Anterior chamber and posterior chamber
Anterior cavity is located where?
in front of the lens
Anterior cavity contains what?
aqueous humor
Posterior cavity is located where?
behind the lens
Posterior cavity contains what?
vitreous humor
What helps maintain intraocular pressure so eyeball does not collapse?
vitreous humor and aqueous humor
Refraction description?
bending light rays to focus on retina
What structures are responsible for refraction?
lens and cornea, aqueous and vitreous humor
Accommodation description?
change in lens curvature
What are two types of accommodation?
near vision and far vision
near vision description?
ciliary muscle contracts, lens bulges
far vision description?
ciliary muscle relaxes, lens flat
Constriction of pupil description?
controls amount of light to provide best vision
Convergence description?
eyes move inward to provide monocular vision of objects
Rods do what?
Responsible for vision in dim light
Cones do what?
Responsible for color vision
Optic nerve description?
Carries mpulse to optic chiasma where nerves cross before ending in geniculate nuclei in brain