The orbit and eye Flashcards
What are the three foramina at the apex of the orbit?
Optic foramen
Superior orbital fissure
Inferior orbital fissure
What passes through the optic foramen?
Optic nerve
Ophthalmic artery
What passes through the superior orbital fissure?
Cranial nerve 3, 4 and 6
Ophthalmic division of trigeminal nerve
Ophthalmic veins
What passes through the inferior orbital fissure?
Maxillary division of trigeminal nerve
What are the main contents of the orbit?
Eye Extrinsic ocular muscles Ligaments supporting the eye Optic nerve Branches of ophthalmic artery Lacrimal apparatus (Tears) Adipose fat
What are the components of the fibrous coat of the eye?
Sclera
Cornea
What are the components of the vascular coat of the eye?
Choroid
Iris
Ciliary Body
What are the components of the inner sensory layer of the eye?
Retina
What is the name given to the watery fluid in the anterior segment of the eye?
Aqueous Humour
What is the name given to the gel in the posterior segment?
Vitreous Humour
What part of the eye produces aqueous humour?
Ciliary body
What are the names of the intrinsic muscles of the eye?
Ciliaris
Constrictor Pupillae
Dilator Pupillae
Where is the ciliaris located?
Ciliary body
What is the innervation of both constrictor papillae and ciliaris?
Parasympathetic via Cranial Nerve III
How many muscles are there which move the eye?
6
Of the extrinsic muscles of the eye, how many are recti and how many are obliques?
4 recti
2 obliques
What is the only muscle that does not arise from the posterior aspect of the orbit?
Inferior Oblique
Name the ligaments that prevent over adduction and over abduction of the eye
Medial and lateral check ligaments
What is the function of the suspensory ligament of the eye?
Supports the eye and prevents downwards displacement
Name the branch of the internal carotid artery that supplies the orbit and the eye
Ophthalmic Artery
Which foramina in the orbit do the ophthalmic veins pass through to enter into the cavernous venous sinus in the cranial cavity?
Superior Orbital Fissure
What is the action of the medial rectus?
Adduction
What are the actions of the superior rectus?
Elevation
Adduction
Intorsion
What are the actions of the superior oblique?
Depression
Abduction
Intorsion
