Exercise 24 Flashcards
Lacrimal gland
Produces and secretes tears onto eye surface
Lacrimal canal
Drains tears from eyes into lacrimal sac
Conjunctivitis
AKA pink eye. Inflammation of the bulbar conjunctiva. Viral, sometimes bacterial infection. Very contagious, more common in children
Bulbar conjunctiva
Protective mucous membrane that covers anterior part of white of eye BUT NOT CORNEA
Fibrous tunic
Cornea & sclera. Provides structural shape of eye
Cornea
Transparent, avascular, allows light to enter through pupil
Astigmatism
Caused by irregularities in the curvature of cornea or lens causing parts of image to be blurry
Sclera
White of eye, forms most of eyeball
Sclearal venous sinus (SVS)
AKA canal of Schlemm. Opening found at the junction of the cornea and sclera. FUNCTION: Collects aqueous humor from anterior chamber and delivers it into bloodstream via anterior ciliary veins
Vascular tunic
Iris, ciliary body, choroid. Contains blood vessels
Iris
Smooth muscle, controls size of pupil. Contains melanin, forms eye color.
Pupils
Opening that allows light to enter the vitreous chamber to reach the central fovea of the macula lutea of the retina which affects focus
Ciliary body
Ciliary muscle & ciliary process
Ciliary muscle
Smooth muscle that changes shape of the lens
Ciliary process
Attached to suspensory ligaments that are attached to the lens. Produces aqueous humor
Aqueous humor
Fluid located in the anterior cavity of the eye. Produced by ciliary process & drained by scleral venous sinus back into blood. Provides nutrients & oxygen, removes waste products for lens & cornea
Anterior cavity
Anterior chamber & posterior chamber. Between cornea & lens. Contains aqueous humor produced by capillaries in ciliary process
Anterior chamber
Between cornea & iris
Posterior chamber
Between iris & lens
Choroid
Contains blood vessels, nourishes retina. Contains tapetum (green-blue, night vision, not found in humans)
Sensory tunic
Retina. Contains neural tissue from outgrowth of the brain
Retina
Pigmented layer & 3 layers of neurous: photoreceptor, bipolar cell, ganglion cell. Nervous tissue. Used to communicate visual information to the brain.
Photoreceptor layer
Deepest neural layer. Contains rods (black & white images) & cones (color images)
Bipolar cell layer
Middle neural layer
Ganglion cell layer
Superficial neural layer. Contains neurons whose axons exit eye as optic nerve
Lens
Important for focusing images. Avascular & made of proteins that are transparent. Divides interior of eye ball into 2 cavities: anterior cavity (anterior & posterior chamber) & vitreous chamber (posterior cavity)
Cataract
Loss of transparency of the lens
Causes of cataract formation
Age, diabetes
Glaucoma
Most common kind of blindness. Can occur if aqueous humor fails to drain out the scleral venous sinus causing increase in pressure within anterior cavity of eye called intraocular pressure. Fluid compressed lens into posterior cavity & puts pressure on neurons of retina
Vitreous chamber
Posterior cavity. Space between lens & retina filled with vitreous body (thick gel-like substance) which holds retina flat against choroid
Macula lutea
Center of neural portion of retina (site of macular degeneration)
Macular degeneration
Age-related macular disease. Generative disorder of retina in people over 50. Lose ability to see straight ahead (peripheral vision retained).
2 types:
“dry” AMD: pigmented layer of retina atrophies & degenerates.
“wet” AMD: new blood vessels form in choroid & leak plasma or blood under retina (laser surgery used to destroy leaking blood vessels)
Central fovea (fovea centralis) of macula lutea
Located in middle of macula lutea. Where image is best focused on retina. Highest concentration of photoreceptors. No ganglion or bipolar cells
Optic disc
AKA blind spot. Region of optic nerve & blood vessels. No photoreceptors hence “blind” spot
Optic nerve
Nervous tissue of retina exits eyeball as optic nerve
Which lobe of brain interprets information for vision?
Occipital lobe
Visual pathway
Optic nerve (axons of ganglion cells) -> optic chiasm -> optic tract -> primary visual area of cortex in occipital lobe of brain
Detached retina
Can occur due to trauma or age-related macular degeneration. Deteachment occurs between neural portion of retina & pigmented epithelium
Color blindness
Inherited inability to distinguish between certain colors. Results from absence or deficiency of one of the three types of cones.
Most common color blindness
Red-green color blindness. Red or green cones missing
