Lab 5 Flashcards
Aqueous humor
Liquid in eye that provides nutrients to cornea and lens
Lens
Behind the cornea and pupil, retracts and focuses light
Suspensatory ligament
Holds lens, adjusts lens shape with ciliary body
Vitreous humor
Jelly like substance that maintains pressure on retina
Pupil
Adjusts light amount that reaches retina
Sclera
Site of muscle attachment, protects and anchors eye
Cornea
Refracts light
Choroid
Provides nutrients to retina
Ciliary body
Smooth muscle that adjusts shape of lens to bend light to fovea
Iris
Traps excess light, muscles that change size of the pupil
Ora serrata
Site where ciliary body meets choroid
Retina
Houses photoreceptors, responsive to light, phototransduction
Optic disc
Site if axons leaving eye, vessels entering, blind spot
Macula lutea
Site of many cones, contains fovea centralis
Fovea centralis
Focal point, highest density of cones (no rods), where bright light is focused to for sharpest resolution
Photoreceptors
Cones and rods in retina, responsive to light energy, relay signal to bipolar cells
Bipolar cells
Neuron in chain between photoreceptor and ganglion cell
Ganglion cells
Part of retina, Neurons that receive information from bipolar cells, axons make up optic nerve, carry signals to brain
Blind spot
Optic disc, where the optic nerve exits the eye, contains no photoreceptors so light hitting this area is not seen
Visual acuity
Ability to distinguish separate images in the visual field
Astigmatism
A defect in an eye or lens caused by a deviation from spherical curvature which results in distorted images, light rays are prevented from meeting at a common focus
Myopia
Nearsightedness, near objects are clearly seen but not far
Hyperopia
Farsightedness
Afterimages
Persistent signaling in the visual system despite removal of the stimulus, caused by ongoing bleaching of photopigments
Bleaching
Photopigment degeneration caused by light stimuli, triggers signaling in the visual pathway
Color blindness
Reduced ability to distinguish between different colors, inability to produce certain cone pigments or have functional cones due to genetic variation
Accommodation
Changes in lens shape and pupil diameter to adjust for focusing light to appropriate areas on the retina for seeing clearly
Convergence
Medial rotation of eyes for close up objects
Depth perception
Ability to determine relative distance of objects in visual field
Visual field
Area that can be seen with eyes and head in fixed position
Optic chaism
Optic nerves merge, some fibers cross over
Optic tract
Axons from optic chiasma to thalamus
Optic radiation
Axons from thalamus to occipital lobe
Visual field defect
Inability to see certain areas of visual field
Lens shape
Distant objects: flattening of lens and pupil dilation
Close objects: pupil constriction and horizontal bulging of lens