The Human Eye
1. Fibrous tunic - outer protection and support.* non-elastic (it has the same constant refractory index)* consists of high amounts of collagen fibers* only organ transplanted from one individual to another without rejection* for light refraction (light bending),(most important. feature regarding refraction)* cornea and lens are involved with refractiono the lens is not part of any tunic, because of the variable elastic change (it is elastic) hence the refractive index can change, the lens is also avascular* non-elastic (therefore part of the tunic)* anchors extrinsic eye muscles LR6[SO4]3* the optic nerve, CN II , pierces the sclera in the back of the eye creating a blind spot (where there is no sight) = optic disc * perioptic nerve exits out of the eye where the optic disc / blind spot is located* the optic disc lacks photoreceptors: rods and cones
circular muscle - cones, color, central vision, close visionc) iris - is a continuation of the cilliary body/ cilliary muscle. glucose and amino acids to enter the lensd) pupil - pin point structure that allows for light to enter the lens3. distinguishing colorLight Adaptation vs. myopia - nearsighted, image converges in front of retina instead of striking the retina, problem is fixed using a concave lens3. * Occurs very fast 5- 10 minutes* cones are more active and the rods are inactivated* Visual acuity/central vision improves as you go into a light room2. * visible colored portion of our eye* allows for diffusion of O2 and nutrients in the monomer unit: i. More numerous than cones but less specialized 1. radial muscle - (longitudinal), important in distinguish dim lightii. Night blindness - nyctolopia, prolonged deficiency in vitamin A, causes rod degenerationHomeostatic Imbalances of the Eye1. Vascular tunic - also called the uvea, forms the middle tunicUvea has 4 regionsa) choroid - contains melanocytes and serves to absorb light and prevent light from scattering with in the eye ball itselfb) cilliary muscle body - continuation of choroid, made of smooth muscle, attaches to the suspensory ligaments (made of collagen fibers). Function best in bright light involves with central vision (visual acuity) distinguish color3.
Common topics in this essay:
CN II,
Tunics Eye,
Light Adaptation,
Rods Cones,
Imbalances Eye,
Endocrine System,
Pathologies Color,
central vision,
optic disc,
photoreceptors rods cones,
central vision visual,
peripheral vision,
rods cones,
vision visual,
visual acuity,
vision visual acuity,
* optic,
eye *,
blind spot,
photoreceptors rods,
,
striking retina fixed,
retina fixed using,
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