Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
21 Cards in this Set
- Front
- Back
|
3 layers of the eyeball (deep to superficial) |
1. Sensory layer - retina
2. Vascular layer - uvea 3. Fibrous layer - sclera and cornea |
|
|
2 segments and 2 chambers of the eye |
Anterior segment = anterior to lens Posterior segment = posterior to lens Anterior chamber = anterior to iris Posterior chamber = posterior to iris |
|
|
Innervation to lacrimal gland |
Parasympathetic from facial nerve |
|
|
Drainage of tears from the eye |
Into the lacrimal sac - through nasolacrimal duct - into inferior meatus of nasal cavity |
|
|
Functions of the tear film (4) |
- keeps cornea moist, prevents drying - washes away foreign antibodies - has antibodies and lysozymes to kill microbes - smooths cornea to provide a smooth surface for refraction |
|
|
3 layers of the tear film |
1. Mucinous layer - overlying corneal epithelium 2. Aqueous layer - lies over mucinous layer 3. Oily layer |
|
|
3 changes that allow accommodation (focusing from a far object to a near one) |
1. Lens changes shape (thicker) - ciliary muscles contract 2. Pupil constricts - pupillae muscles contracts 3. Eyes converge - medial rectus of both eyes contrac |
|
|
Visual pigments found in rods and cones |
Rods = Rhodospin Cones = Opsins S, M and L |
|
|
How does the bleaching of the visual pigment result in phototransduction? |
Phototransduction cascade |
|
|
What role does Vitamin A play in the visual pigment? |
Visual pigment regeneration |
|
|
Myopia |
Short sightedness = close objects look clear, far objects look hazy - image forms in front of the retina |
|
|
Hyperopia |
Far sightedness = close objects look hazy, far objects look clear - image forms behind the retina |
|
|
Astigmatism |
More than one image forming on the retina Surface has different curvature meridians |
|
|
Presbyopia |
Long sightedness of old age - eyes lose the ability to accommodate |
|
|
Innervation of extrinsic ocular muscles |
Trochlear = superior oblique Abducent = lateral rectus Oculomotor = everything else |
|
|
RADSIN |
Recti ADduct, Superiors Intort NOT medial rectus and lateral rectus |
|
|
Visual field (def.) |
Everything you see with one eye including the periphery is your visual field |
|
|
Visual Pathway |
- Optic nerve to optic chiasma - Nasal fibres cross over in the optic chiasma - The optic tracts contain all fibres that have information from the opposite visual field - Optic tract synapses at the LGB on the thalamus - Optic radiation goes to the primary visual cortex (area 17) |
|
|
Pathway for pupilary reflex |
- Fibres don't go to LGB, go to CN III nucleus in the midbrain - Part of CN III nucleus = EWN - From EWN - pre-ganglionic fibres pass through CN III and synapse in the ciliary ganglion |
|
|
Signs of Horner's syndrome |
- Anisocoria = unequal size of pupils - Ptosis = drooping of the eyelid - Miosis = constriction of the pupil - Anhidrosis = loss of sweating |
|
|
Common conditions of the eye |
- Cataract - Glaucoma - Corneal ulcer - Corneal dystrophy - Uveitis - Stye and Chalazion |
