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The Eye (exam 2)
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The Lens
Focuses light on retina
Pupil
Adjustable opening to control amount of light that enters
Concave lens
Causes light waves to diverge
Convex lens
Causes light waves to converge
Eye Accommodation
Used for up close objects
Light waves enter diverged -> increased accommodation
Increase lens curvature (more round)
Parasympathetic control
If ciliary muscles contract
There will be decreased tension on zonular fibers
Lens becomes more round -> greater refraction
If Ciliary muscle relax
There will be more tension on zonular fibers
Making the lens more flat
Circular muscles
Parasympathetic control -> contract muscle
Results in pupillary constriction
Radial muscles
Sympathetic control -> Contract muscle
Pupillary dilation
3 layers of the retina
Photoreceptors (outermost)
Bipolar cells (middle)
Ganglion cells (innermost)
Photoreceptors
Outmost layer of retina
Rods and cones
Generate graded potentials
Bipolar cells
Generate Graded potentials
Middle layer of retina
Ganglion cells
Innermost layer of retina
Generate ACTION potentials
Rods
Express rhodopsin pigment protein (Opsin and retinal)
Retinal is the light absorbing portion
Sensitive to light (Night vision)
Many bind to one bipolar cell
Distributed high on periphery of fovea
Cones
Express 3 opsins pigment protein attached
Less sensitive to light (color)
High resolution
High distribution at fovea
s-cone
Blue
M-cone
Green
L-cone
Red
Author
michaelirby98
ID
300245
Card Set
The Eye (exam 2)
Description
Physio
Updated
2015-04-08T08:07:04Z
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