Eye Flashcards
Vision is broken into what 3 components?
Light entering eye, focused on retina
Retina transduction of light
Cortex processing and interpretation
Developement of they eye occurs?
Extension of the forebrain
3 layers of meninges continue and are modified
Dura Mater —>
Sclera/Cornea
Arachnoid and Pia mater —>
Uveal layer (Choroid, Ciliary body, Iris)
Neural Tissue —->
Retina and several layers of neurons like the cerebrum
Layers of the eye?
S C R V
Sclera
Choroid
Retina
Vitreous Humor in the postremal chamber
The eyes diameter is?
2.5 CM
Iris
Controls the amount of light falling onto the retina by controlling size of opening pupil
Cornea
Primary refraction/focusing of light entering the eye
Lens
Secondary focusing of objects onto the retina
They eye is divided into 2 compartments by the?
Lens
The anterior compartment contains a transparent watery substance that is continually made and drained, ____ ____
Aqueous humor
The posterior compartment contains a transparent gel substance that is formed embryologically, ____ ____
vitreous humor
Vitreous body supports?
Lens and retina from within as well as providing optical medium
Vitreous body contains a canal which extends from the exit of the optic nerve to the posterior surface of the lens called?
It represents the course of the ____ ____ a which supplied the vitreous body during embryological development.
Hyaloid canal
Degenerated hyaloid artery
Junction between sclera and cornea is?
Limbus
The cornea is AVASCULAR consisting of what 5 structures?
- Stratified squamous epithelium
- Bowman’s Membrane
- Substantia propia
- Descemet’s membrane
- Endothelial cells
Corneal reflex utiilizes which CN’s?
Sensory - V
Motor - VII
Which is the most common cause of blindness?
How doe sit occur?
Glaucoma
Too much fluid, intraocular pressure increases; disruption between canal of Schlemm and Trabeculae
Lens fibers contain?
Crystalline protein
Cataracts?
Lens becomes cloudy or opaque
If light contacts a concave lens it will?
Scatter
If light contacts a convex lens it will?
Converge
The ____ is the most anterior part of the uveal layer of the eye.
Iris
Iris arises from?
Ciliary body
Iris consists of two layers
Stroma (Pigmented tissue
Epithelial cells
The color of the Iris depends on the amount of pigment in the?
connective tissue stroma
Blue eyes contains ____ stromal pigment whereas Brown eyes have ____ stromal pigment
Little; considerable
The photosensitive retina forms the inner lining of most of the posterior compartment of the eye and terminates along a scalloped like behind the ciliary body called?
Ora serrata
The visual axis of the eye passes through a depression in the retina called?
Fovea
The fovea is surrounded by a yellow pigmented zone called?
Macula lutea
The ____ retina is the area of greatest visual acuity and contains only ____ photoreceptors
fovea; cone
Afferent nerve fibers from the retina converge to form the ____ nerve which leaves the eye via numerous perforations through a part of the sclera known as the ____ ____.
Optic; lamina cribrosa
The retina overlying the lamina cribrosa, the ____ ____ (____ ____) is devoid of photorecptors and is thus referred to as teh “____ ____”.
optic papilla (optic disc); “blind spot”
Internal nuclear layer is AKA?
Interneurons layer
Layer between Choroid and Rods and Cones is called?
Pigmented layers
Retina is divided into 10 distinct histological zones/FIVE functional groups of cells.
What are the FIVE functional groups of cells.
Pigmented epithelial cells (rests on Choroid) Rod and Cone photoreceptor cells Interneurons and Bipolar cells Ganglion cells Muller cells
RODS:
The outer segment has a regular, cylindrical shape and contains a stack of flattened ____ ____ which incorporate the visual pigment ____ (purple).
membranous discs; rhodopsin
Rods are ____ to low level light
sensitive
Rods are more ___ than cones and more ____ located
numerous; peripherally
CONES:
The outer segment of the receptor proper is a long, conical structure containing _____ _____ instead of discs.
membranous invaginations
The cones contain pigments (____) preferentially receptive to ____, ____ or ____ light.
(rhodopsin); blue, green, or red
Cones are located more CENTRALLY near the?
Fovea
At the fovea; DIFFUSION occurs from?
Choroid layer underneath
The blood supply of the eye is derived from the OPHTHALMIC ARTERY via two separate systems?
Retinal and Uveal systems (ciliary arteries)
One can see FLOATERS in what type of detachment?
RETINAL DETACHMENT
Aqueous cannot drain through meshwork:
A) Open Angle Glaucoma
B) Angle Closure Glaucoma
A) Open Angle Glaucoma
If the ____ pulls away from the ____, _____ can be seen. The pull can lead to a ____ tear; which is more significant since it can lead to BLINDNESS.
vitreous; retina, floaters; retinal
Ciliary muscle is RELAXED:
Suspensory ligament ____, lens ____
Taught; flat
Ciliary muscle is CONTRACTED:
Suspensory ligament ____, lens ____ and ____
slackens; thick and curved
Innervation is ____ from ____ nerve –> ____ ganglion –> ____ ____ n
parasympathetic; oculomotor; ciliary; short ciliary
