Muscles Of The Eye Flashcards
Intrinsic muscle use
Control pupil diameter
Accommodation to see near objects
Extrinsic muscle use
Move the eye
What elevates the eyelid?
Lavator palpebrae superioris
Where does the superior oblique arise from?
Roof of obit posteriorly
Where does the inferior oblique arise from?
Floor of orbit anteriorly
What supplies the lateral rectus?
Abducens (lateral rectus abducts)
What does the trochlear nerve supply
Superior oblique
What movement is intorsion?
Top of eyeball rotates towards the nose
Extorsion is what?
The top of the eyeball moving away from the nose
Why do ocular muscles have more than one action?
They’re attached along the orbital axis
What is strabismus?
Squint
Misalignment of the eye
What’s esotropia?
Manifests as a convergent squint
What’s exotropia?
Manifests as a divergent squint
What’s amblyopia?
Lazy eye
Why does amblyopia occur?
Brain suppresses image of one eye leading to poor image without any pathology
When does diplopia occur?
Occurs in squints as a result of nerve palsies
What supplies the intrinsic eye muscles the cilliaris and the constrictor muscles in the papillary body?
PS III
What supplies the dilator pupillae?
Sympathetic plexus around blood vessels
Pupillary constriction; P or SP?
SP
Dilation of pupils; P or SP?
S
Pathway of the light reflex afferent limb
Light falls on retina Impulses travel along optic nerve Optic chiasma Optic tract Midbrain Edinger-Westphal nucleus (EWN of both sides)
In what conditions would the pupils look different sizes?
Horner’s syndrome
Where is optic neuritis commonly seen?
MS
4 S+S of horner’s syndrome
Unequal pupil sizes
Ptosis
Miosis (excessive constriction of pupils)
Anhidrosis (loss of sweating of affected side)
