eye and ear Flashcards
what is the bony orbit
bilateral, symmetrical cavities containing the eyeballs and associated structures
bones of the bony orbit anterior/lateral view
- frontal bone
- sphenoid bone
- ethmoid bone
- lacrimal bone
- palatine bone
- maxilla
- zygomatic bone
bones of the bony orbit medial view
- frontal bone
- sphenoid bone
- zygomatic bone
- maxilla
- palatine bone
holes within the bony orbit
superior orbital fissure
inferior orbital fissure
optic canal
nerves related to superior orbital fissure
- oculomotor nerve (CN III)
- trochlear nerve (CN IV)
- ophthalmic division of trigeminal nerve (CN V1)
- abducens nerve (CN VI)
nerves related to optic canal
optic nerve
layers of the eye
outer fibrous layer
middle vascualr layer
inner neural layer
outer fibrous layer
sclera and cornea
middle vascular layer
Uvea: iris, ciliary body, choroid
inner neural layer
retina
cornea
- first refraction of light entering the eye
- directs light to lens
- avascular
sclera
- supportive outer white layer
- attachment site for extraocular muscles convered by mucous membranes (conjunctive) to lubricate eye
- vascular
limbus
transition zone between cornea and sclera
iris
- contains pupillary dilator and sphincter muscles
- controls pull size depending on light and nervous system
ciliary body
- produces aqueous humour
- contains ciliary muscles
- helps focus lens using zonular fibers and ciliary muscles
lens
focus light on retina
intraocular
within the eye
extraocular
outside the eye
ciliary muscles
form ring around the eye
what happens when ciliary muscles are relaxed
they expand
- zonular fibers tense
- lens flattened for focusing on distant objects
what happens when ciliary muscles constict
- they contract
- zonular fibers relax
- lens are rounded for focusing on close objects
explain what happens with the ciliary muscles when viewing distant object
- ciliary muscles relax
- zonular fibers tighten
- lens flatten
explain what happens with the ciliary muscles when viewing close object
- ciliary muscles contract
- zonular fibers relax
- lens thickens
which of the following is true?
1. when viewing distant objects, the ciliary muscles contract, which tenses the zonular fibers and flattens the lens
2. distant objects, the ciliary relax, which relaxes the zonular fibers and flattens the lens
3. near objects, the ciliary contract, relaxing the zonular and thickens the lens
4. near objects, ciliary relax, tensing the zonular fibers and flattens the lens
3.