Orbit Flashcards
Functions of the eyelid?
Protect eyelid, spread lacrimal secretions across surface and shade eyelid
What is the palpebral fissure?
Space between the corners of the eyes (medial and lateral canthi) – opening of eyelids basically
Where is the ciliary gland located?
Within the subcutaneous tissue of the eye
What results from ciliary gland infection?
Sty
Origin, insertion, innervation and action of levator palpebrae superioris
O: lesser wing of sphenoid
I: Skin of upper eyelid and tarsal plate
IN: oculomotor nerve (III)
Action: elevate eyelid
Origin, insertion, innervation and action of superior oblique
O: Body of sphenoid
I: Through trochlea to sclera
IN: Trochlear nerve (IV)
Action: Depress and ABduct eye
Origin for the rectus muscles?
Common tendinous ring
Insertion for the rectus muscles?
Sclera posterior to cornea
One rectus muscle not innervated by oculmotor nerve?
Lateral rectus - abducens nerve (VI)
Ptosis?
Drooping of upper eyelid
What can cause complete ptosis?
Destruction of the oculomotor nerve or one of its branches to levator palpebrae superioris
What muscle originates at the lesser wing of the sphenoid but inserts on the tarsal plate of upper lid?
Tarsal muscle (of Muller)
What causes slight ptosis?
Paralysis of tarsal muscle
Symptoms of Horner’s syndrome?
Paralysis of tarsal muscle Slight ptosis Miosis Enopthalmos Anhidrosis and blushing
Pupillary constriction due to paralysis of dilator pupillae muscle
Miosis
Posterior displacement of the eye
Enopthalmos
Inability to sweat normally
Anhidrosis
What innervates the tarsal muscle?
Post-ganglionic fibers (smooth muscle)