Eyeball (draw sagittal section)-vascular supply, innervation, chambers, aqueous humour circulation

Eyeball:

We have 2 eyeballs located in the bony orbit of our skull. The eyeballs are responsible for sight, one of the 5 senses. Sight, like the other senses is closely related to other parts of our anatomy. The eye is connected to the brain and dependent upon the brain to interpret what we see.

Vascular supply, innervation:

VASCULAR SUPPLY:

ARTERIAL:

The main blood supply of the eye arises from the ophthalmic artery, which gives off orbital and optical group branches.

Origin: ophthalmic artery Orbital group branches: lacrimal, supraorbital, posterior ethmoidal, anterior ethmoidal and medial palpebral arteries Optical group branches: long posterior ciliary, short posterior ciliary, anterior ciliary and central retinal arteries

VENOUS:

Central retinal, superior ophthalmic, inferior ophthalmic and middle ophthalmic veins

INNERVATION: Innervation of the eyeball and surrounding structures is provided by the optic (CN II), oculomotor (CN III), trochlear (CN IV),  abducens (CN VI) and trigeminal (CN V) cranial nerves.  

Optic nerve: sight

Short ciliary nerves: miosis and lens accommodation

Long ciliary nerves: mydriasis

Oculomotor, trochlear, abducens nerves: ocular movements

Ophthalmic branch of trigeminal nerve: eyeball, upper eyelid, nose ridge sensation

Aqueous humor circulation:

The flow of aqueous humor begins in its production by the ciliary body, in the posterior chamber of the eye. From the ciliary body, aqueous humor flows through the pupil and into the anterior chamber.

Aqueous humor then leaves the anterior chamber through a structure called the drainage angle. Once inside the drainage angle, the aqueous fluid leaves the eye through a spongy tissue called the trabecular meshwork.

The trabecular meshwork moves the liquid into a drainage canal, called Schlemm’s canal, where the aqueous humor then drains into the eye’s circulatory system.