Eyes and vision Flashcards
Which wall of the orbit is most commonly fractured?
Medial
Where is aqueous humour?
In the anterior chamber of the eye
Which muscle controls accommodation?
The ciliary muscle
Which structure forms aqueous humour?
Epithelium of ciliary body
Where does aqueous humour drain?
Anterior chamber angle
What attaches ciliary processes to the lens of the eye?
Zonules
Which muscle controls the shape of the lens of the eye?
Ciliary muscle
Which layer of the sclera contains lots of blood vessels?
Choroidal layer
What is characteristic of the blood vessels at the fovea?
There are none!
Where are cones most highly concentrated in the eye?
The fovea
What do we call the bit of the eye where the optic nerve leaves?
The optic disc
What artery is visible when you look through an ophthalmoscope?
Central retinal artery
Which muscle closes the eyelids?
Orbicularis oculi
Which nerve controls orbicularis oculi?
Facial nerve
What percentage of photoreceptors are rods?
95%
What percentage of photoreceptors are cones?
5%
Which cells provide their axons to the optic nerve?
Retinal ganglion cells
What is the three-cell pathway from light transduction to optic nerve?
Photoreceptor => bipolar cell => retinal ganglion cell
The 2 functional visual pathways begin in the retina with which types of cells?
M cells and P cells
What are M cells of the retina specialised for detecting?
Motion
What are P cells of the retina specialised for detecting?
Colour and visual acuity
Homonymous hemianopia with macular sparing suggests infarction of which artery?
PCA
Homonymous quadrantanopia suggests infarction of which artery?
MCA
Which artery supplies the optic tract?
Anterior choroidal artery
Which retinal cells give input to the suprachiasmatic nucleus and superior colliculus?
Intrinsically photosensitive ganglion cells
Which two nuclei are involved in the pupillary light reflex?
Pretectal nucleus and Edinger-Westphal nucleus
How do you best isolate the action of superior oblique?
Depress the eye whilst adducted
How do you best isolate the action of inferior oblique?
Elevate the eye whilst adducted
What is origin of the superior rectus muscle?
Common tendinous ring
What is the origin of the inferior oblique?
Attachment to maxilla
What is the only muscle that can elevate the eye when it is abducted?
Superior rectus
Where is the horizontal gaze centre?
Pontine paramedian reticular formation
Where is the vertical gaze centre?
Mesencephalic paramedian reticular formation
Which layer of V1 do the optic radiations terminate in?
4C
Which cortical area is especially specialised for colour processing?
V4
A monocular visual field defect suggests what?
Lesion is before level of optic chiasm
