this week we skinned her face and took out rose's eyeball. we have literally dissected every other part of her body and yet i felt invasive and shy when it was time to use tools on her eyeball. it took about 20 minutes to get the eye out of the socket. i was surprised how robust the eye muscles are, how deep the socket is, and how much fat is behind the eyeball. it makes sense that there is so much structure and protection for the eyeball, though. it is our most important sense, in terms of survival.
speaking of survival, i got to thinking about the optic chiasm and couldn't remember why the nerves cross, so i looked it up. at the optic chiasm, nerve fibers from half of each retina cross over to the opposite side of the brain. the fibers from the other half of the retina travel to the same side of the brain. because of this junction, each half of the brain received visual signals from the visual fields of both eyes. this is a great evolutionary benefit for humans because vision is so important for our survival.
No comments:
Post a Comment