Orbit. Walls, communications, and elements passing through them

orbit (eye sockets)

- are bilateral cavities in the head which enclose the eyeball and its associated structures

- can be thought of as a pyramidal structure with the apex pointing posteriorly and the base anteriorly

borders of the orbit

- roof: formed by the orbital part of frontal bone & lesser wing of sphenoid bone

- floor: formed by maxilla, palatine & zygomatic bones

- medial wall: formed by lacrimal, sphenoid, maxilla & ethmoid bones

- lateral wall: formed by zygomatic bone & greater wing of sphenoid bone

- apex: located at the opening to the optic canal; optic foramen

- base: opens out into the face and is bounded by the eyelids (orbital rim)

several structures that pass through the orbit (talk abt....)

- extra-ocular muscles

- eyelids

- nerves

- blood vessels

extra-ocular muscles

- they're separated from the eye

- responsible for the movement of the skull

eyelids

covers orbits anteriorly

nerves (several cranial nerves supply the eye and its structures:)

- optic nerve

- oculomotor nerve

- trochlear nerve

- trigeminal nerve

- abducens nerve

blood vessels

- the eye receives blood vessels from ophthalmic artery

- venous drainage is via the superior & inferior ophthalmic veins

3 main openings that lead into the orbit:

- superior orbital fissure

- inferior orbital fissure

- optic canal

superior orbital fissure

- transmits the superior ophthalmic vein

- transmits a number of nerves:

~ lacrimal nerve

~ facial nerve

~ trochlear nerve

~ oculomotor nerve

~ nasociliary nerve

~ abducens nerve

inferior orbital fissure

transmits the

- zygomatic branch of the maxillary nerve

- inferior ophthalmic vein

- sympathetic nerves