Topic 6 Nervous System: Eye

Question 1

• Cornea (focuses light) -> pupil (diameter controlled by pigmented iris) -> lens (thickness controlled by ciliary muscles; responsible for focusing images) -> retina (light sensitive cells)

Answer 1

Path of Vision

Question 2

• The eye is surrounded by the sclera, a connective tissue layer, and beneath this is the choroid, a vascular layer providing blood and nutrition to the retina

Answer 2

Note

Question 3

• Cones
• Rods
• Fovea

Answer 3

Retina contains the following structures

Question 4

• responsible for perceiving high intensity illumination and are sensitive to color

Answer 4

Cones

Question 5

• receptive to low-intensity light; are important in night vision and do not perceive color
  a. Rods perceive light via the pigment rhodopsin which, when struck by photons of light, causes hyperpolarization transduced into a neural action potential sent to the brain
  b. Photoreceptor cells synapse to bipolar cells -> ganglion cells -> axons of ganglion cells bundle to form the optic nerve
  a. The point at which optic nerve exits is the blind spot, at which no photoreceptors are found

Answer 5

Rods

Question 6

• an area with the most dense concentration of cones and is important for high acuity vision

Answer 6

Fovea

Question 7

• Vitreous Humor

- Aqueous Humor

Answer 7

Eye contains two types of humors or liquids

Question 8

• jelly-like liquid between the lens and retina that maintains eye shape and has optical properties; makes up most of the eye volume

Answer 8

Vitreous Humor

Question 9

• watery liquid that fills anterior chamber between the lens and cornea; the eye produced this in order to maintain intraocular pressure and provide nutrients to the avascular ocular tissues

Answer 9

Aqueous Humor