Neuro: Vision Flashcards
What are the 2 halves of the retina called?
- Temporal retina - half closest to temporal bone of skull
- Nasal retina - half closest to the nose
When looking at the world you have a temporal field of view and a nasal field of view, define each type of visual field
- Temporal field of vision - field of vision towards temporal bone
- Nasal field of vision - field of vision towards the nose
What part of the retina focuses light coming from temporal field of view and what part of retina focuses light coming from nasal field of view?
- Temporal retina focuse light from nasal field of view
- Nasal retina focuses light from temporal field of view
What is the sclera of the eye?
Sclera is the white fibrous outer layer of the eye
What is the cornea and how is it transparant?
- Cornea is the transparant front part of the eye
- It’s transparant because of the way that the collagen and cells that make up the sclera arrange themselves within the cornea
Why is there a need for the eye to produce intraocular pressure?
Intraocular pressure needed to keep the sclera rigid as it is flexible to a certain degree
How is intraocular pressure created within the eye?
Generated by aqueous humour (fluid that fills the space between cornea and lens)
What part of the eye produces aqueous humour and what part of the eye drains excess aqueous humour away?
- Produced by the ciliary body
- Excess aqueous humour drains into angle of the eye
As you get older what happens to the vitreous humour that fills most of the eye as someone gts older?
- Proteins that make up vitreous humour clump together
- This causes vitreous humour to shrink down and pull away from retina
What parts of the eye make up its optics?
- Cornea
- Lens
- Iris (pupil)
How is the lens able to change shape?
- Lens suspeneded by suspensory ligaments from the ciliary body
- Ciliary body contains ring of muscle and so when that muscle contracts or relaxes it causes the lens to change shape
What is the function of the iris?
Controls the diameter and size of the pupil and thus the amount of light that reaches the retina
Why does the iris need to control the size of the pupil?
- Iris needs to control size of pupil to ensure that light doesn’t hit the edge of the lens
- If light does hit edge of lens it won’t be focused onto retina properly
What are the different parts of the retina?
- Neural retina
- Retinal pigment epithelium
What are the functions of the retinal pigment epithelium?
- Provides biochemical support to photoreceptors
- Prevents retina from peeling away
What does the fact that both the retina and the retinal pigment epithelium developed from the neural tube mean for these structures?
Means they are both Central nervous sytem structures