Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

30 Cards in this Set

  • Front
  • Back
Parasympathetic stimulation of lacrimal glands over-secreation of tears and tears spill over edge of eyelids.
Optic disc. AKA blind spot
Site where optic nerve exits the eyeball
Six Extrinsic Eye Muscles
1.) Lateral & medial rectus
2.) Superior & inferior rectus
3.) Superior & inferior obliques
infection of the ciliary gland
Posterior segment
Larger; between lens and retina and filled with jelly-like substance; vitreous body - formed during embryonic life and does not undergo replacement. Contributes to intraocular pressure and prevents eyeball from collaplsing and keeps retina smoothly pressed against choroid.
Lacrimal fluid
Just superior and lateral to eyeball; almond size/shape; secrets: lacrimal fluid - serous sol. of salts/mucous/lysozyme; lubricates/cleans/moistens eyeball
Fovea centralis
Small depression in center of macula lutea contians cones only that are not covered by bipolar and ganglion cells; area of highest visual acuity or resolution.
Lacrimal apparatus
Group of structures that produce/drain tears, AKA lacrimal fluid.
Macula lutea
Exact center of postior portion of retina
Macular degeneration
New blood vessels grow over macula lutea and distorted vision and blindness results.
Anerior Segment
Anterior to lens; further divided into: anterior chamber - behind cornea/in front of iris filled with serous fluid; aquous humor- formed from blood capillaries in ciliary process; undergoes contant replacement and helps noursih cornea and lens. Forms intraocular pressure, approx. 16 mm Hg, that, along with vitreous body; maintains eyeball shape; keeps retina smoothly pressed against choroid for an even surface for reception of clear images
Wall of the Eyeball
Fibrous tunic: superficial, avascular wall
Cornea: anterior; avascular; transparent membrane covering colored iris; is curved to help focus.refract (bend) light.
Sclera, AKA "white of the eye": dense CT covering all of th eyeball rigid, fiving it shape; protects inner parts
medical instrument to look through pupil to see a magnified image of the posterior wall (fundus of the retina and its anterior blood vessels) (to view pathological changes, as wth HTN or DM)
Vascular Tunic AKA Uvea
Middle wall
a.) Choroid: posterior portion; highly vascular - provides nutrients to posterior retina
b.) Ciliary Body: anterior extension of choroid
c.) Ciliary process: internal folds that secrete serous aqueous humor
d.) ciliary muscle: band of smooth muscle that alters shape of lens
Vascular Tunic - Iris
Flat, donut-shaped, colored portion of eyeball; suspended between cornea & lens; attached at outer margin to ciliary process; regulates the amount of light entering eyeball through the pupil
Just posterior to the pupil and iris, avascular; transparent; consists of onion-layered proteins.
Function: focus/refract light rays for clear vision.
Vascular Tunic - Pupil
Opening/hole in center of iris. Bright light of parasympathetic stimulation, pupil constriction dim light of sympathetic stimulation, pupil dilation
Thin, proctective mucous membrane; lines from inner aspect of eyelids onto anterior eyeball
a.) palpebral - lines the inner eyelid
b.) bulbar/ocular- lines the outer eyeball
c.) bloodshot eyes - dilated blood vess. of conjunctiva on eyeball.
d.) conjunctivitis, AKA pinkeye - inflammation of conjunctive usually caused by bacteria; sometimes caused by an irritant (dust, smoke, pollution)
Accommodation of the lens
Increase in convex curvature of the lens (ant. and post. surface) for near vision.
Presbyopia - with aging, lens loses elasticity and its ability to accommodate.
Physiology of Vision
Visual transduction of light into an electrical signal.
1. Absorption of light by photopigments in rods and cone (photoreceptor).
a.) Photpigment = colored proteins in rods/cones that undergo structural changes when they absorb light.
i.) Rhodopsin - the single photopigment in rods.
ii.) Three different photopigment for three different types of cones (color blindness: due to absence of the cone photopigment sensitive to red or green light).
b.) All photopigment contain:
i.) Opsin - a glycoprotein; 4 diffe. types - 1 for each photopigment and each type (due to variations of a.a. sequences) abosrbs different wavelengths of incoming light.
ii.) retinal a vitamin A derivative; the light- absorbing portion (night blindness - inability to see will at low light levels; caused by a long- term deficiency of vitamin A and decreases amounts of retinal.
c.) When light is absorbed, retinal changes shape (isomerization) and seperates for opsin (AKA bleaching); (in darkness, it is converted back to its
original shape).
d.) decreased release of an inhibitory neurotransmitter, blutamic acid, thereby exciting the bipolar cells that synapse with rods. Bipolar cells that synapse with cones may be excited or inhibited by light.
e.) Excited bipolar cells synapse with, and, excite ganglion cells, which become depolarized and initiate nerve impulses
f.) ganglion cells leave retina as optic (II) nerve fibers, optic chiasm, optic tract, thalamus, primary visual area of occipital lobe of cerebral cortex.
Detached retina
Trauma, eye disorders, detachment between neural layer and pigment layer, fluid accumulates and distorted vision and or blindness results.
Constriciton of the pupil
Autonomic reflex prevents light rays from entering the eye through the periphery of the lens.
Refraction of light rays
75% bu cornea and 25% by lens (for fine-tuning)
Normal - can refract light rays from an object 6 m/20 ft away.
Myopia, AKA nearsightedness - image focused in front of retina.
Hyperopia, AKA farsightedness - image focused behind retina.
Astigmatism - irregularities on surface of cornea of lens prevent image from being focused on retina.
Project from antierior border of each eyelid & Eyebrows- runtransversely above upper eyelids.
Function: protect eyeballs from foreign objects, sweat, direct sunlight
Ciliary (sebaceous) glands - at base of eyelashes' hair follicles; secrete lubricating fluid into follicles.
Sensory Tunic AKA Retina
Innermost wall; has tow layers:
1.) Pigmented Layer (nonvisual); contains melanin; absorbs stray light.
2.) Neural Layer (visual); multilayered outgrowth of th ebrain; 3 layers of retinal neurons to process visual input from external to internal:
I.) Photoreceptor layer - two types
a.) rods
b.) cones
II.) Bipolar cell layer
III.) Ganglion cell layer
Increased intraocular pressue and degeneration of the retina usually resulting in blindness.
Excretory lacrimal ducts
6 - 12 ducts that drain tears from glands onto conjunctiva of upper eyelid; tears pass medially over anterior eyeball.
Upper and lowe- consist of Epith. tissue/CT/Muscle tissue.
a.) protects eyes from excessive light & foreign objects
b.) lubricate eyeballs
c.) shade eyes during sleep
Loss of transparnecy of lens due to aging, injury, UV light exposure, drugs (steriods), other ds.'s (DM) and leading cause of blindness
Superior & Inferior lacrimal puncta
2 small openings at medial eye; tears pass into: Superior & inferior lacrimal canals - drains tears into a lacrimal sac which stores and drains tears into the nasolacrimal duct - carries tears into nasal mucosa (cold) which could cause a blockage and cause watery eyes.