CH 15 Pt. 3: Vision / Eye ( Final Exam ) Flashcards
What are the accessory ( outside ) structures of the eye?
- Conjunctiva & Extrinsic Eye muscles
Where is the Conjunctiva located?
- inside of the eyelids / covers the sclera
What are the 6 extrinsic eye Muscles?
- Superior oblique
- Superior recuts
- Inferior oblique
- Inferior recuts
- Medial recuts
- Lateral recuts
LR6 SO4 _______3 :
- Lateral recuts is controlled by cranial nerve 6
- Superior oblique is controlled by cranial nerve 4
- all other extrinsic eye muscles are controlled by cranial nerve 3
The Extrinsic Eye muscles control what type of muscles?
Skeletal muscles
what is the function of Extrinsic Eye muscles?
Moves eyeballs
What is the most important structure of the eyeball?
Wall of eyeball
3 layers of the wall of eyeball ( outside to inside):
- Fibrous layer
- Vascular layer
- Inner Layer /Retina
What are the 2 parts of the Fibrous layer ?
- Sclera (posterior)
2. Cornea (anterior )
What region of the fibrous layer is called the “white of the eye” & has an opaque posterior regions?
sclera
The sclera is pieced by the ____ nerve posteriorly ?
Optic
The function of the sclera is to ___?
- Protect & Shape the eyeball
What region of the fibrous layer achors extrinsic eye muscles?
Sclera
What passes through the optic canal in the sphenoid bone?
- Sclera ; Dura Mater
What region of the fibrous layer is the most anterior portion of the eye?
Cornea
what region of the Fibrous layer is transparent , avascular and allows light to enter?
Cornea
What are the 3 structures of the eyeball?
- Wall of Eyeball
- internal Cavity
- Lens
What are the 3 regions of the Vascular ( uvea ) Layer ?
- Choroid layer
- Ciliary Body
- Iris
What two regions of the vascular layer are considered as muscles?
- Ciliary body & Iris
What region of the Vascular Layer has many blood vessels?
Choroid layer
What region of the Vascular (Uvea) Layer is the posterior portion of Uvea and supplies blood?
-Choroid layer
What color pigment does the choroid layer produce?
- Choroid layer
what layer connects with the inner layer (retina ) of the eye directly ?
Choroid layer
What is the ring of tissue surrounding lens?
Ciliary Body
The ciliary Body controns the ___?
lens shape
What are the 2 intrinsnic (smooth) eye muscles?
- iris (anterior)
- Ciliary body ( posterior)
What is the colored part of the eye?
Iris
Where is the Iris located?
- under cornea ; small opening
What is the central opening of the iris ?
Pupil
what regulates the amount of light entering the eye ?
Pupil
What are the 2 inner muscles of the Iris?
- spinchter pupillae ( circular)
2. Dialator Pupillae ( Radial)
WHAT Nerve is in the Spinchter Pupillae ?
- Parasympathetic nerve ( rest and digest )
What contracts because of Bright LIGHT & constructs the pupil?
Spinchter Pupillae
What nerve is in the Dilator Pupillae ?
- Sympathetic Nerve ( Fight or flight)
What contracts because of DIM Light & dialates pupil?
Dilator pupil
What is within the inner (retina) layer of the eye?
- pigmented layer ( outer )
2. Neural Layer ( inner)
What is the function of the pigmented layer?
- absorbs light & prevents scattering phagocytize photoreceptor cell fragments
What are the 3 Regions of the Neural Layer?
- Photoreceptors
- Bipolar Cells
- Ganglion Cells
Ganglion Cells:
No reactioni to light
Bipolar Cells:
No reactions to light
Photoreceptors
only react to light
Neuron direction for Light:
“ Gang” - “Bi” - “Photo”
Neuron direction for Action Potential:
“Photo” - “Bi” - “Gang”
What layers have pigment?
- choroid layer & Pigmented layer
How do Ganglioin Cells exit the eye as optic Nerve?
- Ganglion nerves fuse together & form optic Nerves
What is the external view of the neural layer?
- optic Disc
- Fovea of Macula
How do you know left eye from right?
-fovea of maculae is lateral to optic disc
What lacks photoreceptors that causes a blind spot?
Optic Discs
What is the site where optic nerve leaves eyes?
Optic Disc
Vitreous Humor:
Gelled like/ Posterior Side
What holds the neural layer of the retina firmly against Uvea?
Internal Cavity
What changes shape to precisely focus light on Retina & is posterior to the iris ?
- Lens
What has the Vitreous Humor & transmits light ?
Internal Cavity
What is the Vision cortex in the occipital lobe?
Mechanism of vision
Where does the vision cortex in the occipital lobe send action potential?
To the brain by Cranial Nerve II
What are the color of the CONES ?
- Blue, Green, Red
Where are Rods located?
Outside of Fovea
The visual Sensitivity of Rods is ____ and Cones is ____ ?
- High ; Low
The Visual Activity of Cones ____ and Rods is ____ ?
- High; Low