Eye anatomy Flashcards
(32 cards)
What are the 3 movements of the eye
Elevation/depression
abduction/adduction
intorsion/extorsion
What direction does the eye look when the Superior rectus contracts?
laterally and upward
What direction does the eye look when the Inferior rectus contracts?
Laterally and downward
What direction does the eye look when the lateral rectus contracts?
Laterally
What direction does the eye look when the Medial rectus contracts?
Medially
What direction does the eye look when the Inferior oblique contracts?
Medially and upwards
What direction does the eye look when the Superior oblique contracts?
Medially and downward
What muscles does the abducent nerve control
Lateral rectus
What muscles does the trochlear nerve control
Superior oblique
What muscles does the oculomotor nerve control
Medial rectus
Superior rectus
Inferior rectus
Inferior oblique
What are the 3 layers of the eyeball?
Fibrous, Vascular, inner
What makes up the fibrous layer?
Sclera + Cornea
What does the fibrous layer do and look like
White in colour
Maintains eye shape
Has a defect called the lamina cribrosa which allows for entry of optic nerve
What does scleral buckle do?
secure the scleral to the internal eye if it is loose
What causes yellow eyes (sclera) and what is it any early sign of
Build up of bilirubin
liver failure
What is the conjunctiva?
a tissue lining the inside of eyelids & covering sclera
highly vascular
if inflamed vessels dilate and become visible
What does the Cornea do?
allow lights to passthrough & accounts for 60% of optical refractive power
What does the Keratoconus condition cause and what does it look like
Thicker cornea
causes double vision
What is Fuchs Endothelial Dystrophy
an inherited condition that causes vision blurring
prevents dehydration of cornea causing blurring
What makes up the vascular layer?
Choroid, ciliary body & iris
what does the ciliary body do?
acts as suspensory ligaments for the lens
what happens in cataract surgery?
inside of lens is essentially scooped out, refocus the refraction of light
What does the iris muscle do?
dilate constrict the pupil
What is Horners syndrome?
permanently constricted pupil (Miosis)
caused by post-ganglionic sympathetic neurone damage
