Ocular Anatomy and Physiology

35 terms by thyme83189 

Create a new folder

Advertisement Upgrade to remove ads

Ocular anatomy and physiology as it relates to the Ocular Adnexa, the eye as an optical system, other related structures, and the visual pathway.

Length of the eye

24 mm

Limbus

where the cornea and sclera meet

Corneal diameter

12 mm

Refractive surfaces

lens = 1/3
cornea = 2/3

Nerve Fiber Layer (NFL)

made of axons that converge to make one cable (the optic nerve)

Components of the Lens

Capsule, cortex, and nucleus (outer to inner order)

Optic disk color

Pink

Cataracts disease

the aging of the lens (not permanent)

Glaucoma disease

the loss of peripheral vision and affects the optic nerve (permanent)

Components of Ocular adnexa

Eyelids, extraocular muscles, lacrimal apparatus, and orbit

Eyelids

distribute the tear film across the cornea

Meibomian glands

oil secreting, prevent tear evaporation

Obicularis

eyelid closure muscle

Levator

eyelid raising muscle

Conjunctiva

the thin transparent membrane that lines the inner eyelids and the surface of the eyeball (excluding the cornea)

Palpebral fissure

the space vertically between open eyelids, 6-8 mm

Function and Components of Lacrimal Apparatus

Lacrimal gland, punctum, canaliculus, and sac (clockwise from top), responsible for tear production for lubrication and hydration

Orbit

2 inch deep skull cavity, lined by orbital bones. Contains eyeball and its muscles, blood supply, nerves, and fat.

Transparent structures

pre-corneal film, cornea, aqueous, lens, vitreous, and retina

Cornea function and layers

clear, round membrane at front of globe (avascular), which focuses light rays. (front to back) Epithelium, bowman's membrane, stroma, descemet's membrane, and endothelium

Sclera

white, fibrous outer tissue layer that forms the main structure of the globe

Anterior Chamber

space between cornea and iris filled with aqueous, holds up the cornea

Anterior chamber angle

corners of anterior chamber, responsible for aqueous outflow by ant. cham. angle, trabecular meshwork, and canal of schlemm

Iris

the colored structure behind the cornea, and in front of the lens

Pupil

the opening in the center of the iris, dilated (widened) by dilator muscle, and constricted by the sphincter muscle

Uveal tract

pigmentation and blood vessels; composed of iris, ciliary body, and choroid

Lens

behind the iris and in front of vitreous, suspended by zonules attached to ciliary body. focuses on object as they come closer to the eye: accommodation

Vitreous

transparent jelly behind the lens responsible for holding up the eye

Retina

thin, neural tissue which lines between vitreous and sclera, extending to the brain. receives the image before sending to brain for interpretation

Rods

retina photoreceptor cells that interpret night vision and black and white (scotopic)

Cones

retina photoreceptor cells that interpret color vision and sharp central vision

Optic Nerve

in back of the eye connecting eyes to brain, takes retinal images and converts them into neural impulses to go to brain

Visual Pathway

Wiring from optic nerves to occipital cortex in brain: optic chiasm, optic tracts, optic radiations, and occipital cortex

Seven Orbital Bones

Frontal, Sphenoid, Zygomatic, Maxilla, Ethmoid, Lacrimal, and Palatine

Moll and Zeis

glands at base of each cilia (eyelash): sweat and sebaceous (respectively)

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set