Eye Flashcards
(20 cards)
Tunics of the eye
Outer fibrous tunic: sclera, cornea
Middle vascular tunic: iris, ciliary body, choroid
Inner neural tunic: retina
Sclera
posterior connective tissue, appears white, tendons of extrinsic eye muscles attach here
Cornea
transparent collagen, covers lens, refracts the light
Iris
contains blood vessels & pigmented cells
smooth muscle that contracts diameter of pupil
-circular pupillary (constricts)
-radial pupillary (dilates)
Pupil
opening that allows light to enter posterior eye
Choroid
capillary network brings blood supply to retina
Ciliary Body
smooth muscle that attaches to suspensory ligaments
changes shape of lens
Suspensory Ligaments
attach to lens and change its shape during visual accommodation
Lens
organized layer of connective tissue cells, refract light to focus visual image on retina
Retina
entends anteriorly to ora serrata, contains photoreceptors
Rods
- very light sensitive (night vision)
- grainy images
- black and white
Cones
- requires adequate light (day vision)
- sharp clear images
- detect color
- three types of cones
Fovea centralis
Focus point, contains highest concentration of cones for sharpest vision
Blind spot
where optic nerve leaves the eye
Posterior cavity
from lens to iris, filled with vitreous humor
anterior cavity
from lens to cornea, filled with aqueous humor
Conjunctiva
venous epithelium covering anterior sclera and inner eyelid, lubricates and moistens eye
Lacrimal apparatus
produces, distributes, and removes tears
Lacrimal gland
produces 1 mL of tears a day
Visual pathway
photoreceptors bipolar cells ganglion cells optic nerve optic chiasm optic tract 1/4 to superior colliculi of corpora quadrigemina(midbrain) 3/4 to thalamus visual cortex of occipital lobe
