Orbit (anatomy)

As the orbit (from the Latin orbis 'circle' ) is called the bony eye socket, a deep pit in the skull (cranium ), in which the eye and its appendages are. In humans, the pit is deep about 4 to 5 cm.

Involved bone

The orbit is formed by seven bones:

• Lacrimal bone ( lacrimal )
• Upper jaw (maxilla )

In most mammals, the orbit is around bony limited. With predators and pigs, the lateral edge is the temporal fossa ( temporal fossa ) out only by a connective tissue band closed ( orbital ligament ). It runs between the zygomatic process of the frontal bone and the frontal process of the zygomatic bone (see picture dog, # 1 and # 9). The distance between the two orbits is called Interorbitalspatium.

Openings inside

On the inner walls there are a plurality of openings for the passage of nerves and blood vessels, as well as of the tear path.

• Ethmoidal foramen (sometimes multiple openings ) for the passage of the same vessels and nerves
• Optic canal: the passage of the optic nerve ( optic nerve, II) and ophthalmic artery
• Orbital fissure ( in humans superior): for the passage of the other cranial nerves to the eye muscles and the sensory innervation of the eyeball ( oculomotor nerve (III ), trochlear (IV ), ophthalmic nerve (V1 ), Abducens (VI ) )
• Inferior orbital fissure (only human): the passage of the inferior ophthalmic vein, nerve zygomatic and infraorbital ( foramen rotundum or foramen in animals orbitorotundum )
• Lachrymal fossa and foramen lacrimale: lacrimal sac mine, it's all about the hole in the nasolacrimal passage to the nasal cavity (see tear ducts )
• Maxillary foramen: the infraorbital canal for the same nerves and blood vessels, leading to the infraorbital foramen