Let us examine the structure of the orbit (orbita). It is a bony cavity in which the eye, the visual organ, is located. In addition to the eyeball, there are also muscles, the lacrimal gland and some other formations in the orbit.

The opening inserting into the orbit is called the orbital opening (aditus orbitae). The posteromedial part of the orbit is called the apex of the orbit and leads to the optic canal (canalis opticus).

The orbit has four walls:

• a roof (paries superior)

  

• a medial wall (paries medialis)

  

• a lateral wall (paries lateralis)

  

• a floor (paries inferior)

  

  Floor (paries inferior)

• the orbital surface of the frontal bone (facies orbitalis ossis frontalis)

  

• the lesser wing of the sphenoidal bone (ala minor ossis sphenoidalis)

  

  The medial wall is formed by:

• the orbital plate of the ethmoidal bone (lamina orbitalis ossis ethmoidalis)

  

• the frontal process of the maxilla (processus frontalis maxillae)

  

• the lacrimal bone (os lacrimale)

  

• the body of the sphenoidal bone (corpus ossis sphenoidalis)

  

  The lateral wall is formed by:

• the orbital surface of the greater wing of the sphenoidal bone (facies orbitalis alae majoris ossis sphenoidalis)

  

• the orbital surface of the zygomatic bone (facies orbitalis ossis zygomatici)

  

  The floor is formed by:

• the orbital surface of the maxilla (facies orbitalis maxillae)

  

• the orbital surface of the zygomatic bone (facies orbitalis ossis zygomatici)

  

• the orbital process of the palatine bone (processus orbitalis ossis palatini)

In the area of the orbit there are several foramina and fisures through which pass various vessels and a nerve.

Let’s take a closer look at them.

Title	Contents	Connected to
Optic canal (canalis opticus)	Optic nerve, ophthalmic artery	Middle cranial fossa

Superior orbital fissure (fissura orbitalis superior)

Anterior meningeal branch of the anterior ethmoidal artery, superior ophthalmic vein, oculomotor nerve, trochlear nerve, abducent nerve, ophthalmic nerve

Middle cranial fossa

Inferior orbital fissure (fissura orbitalis inferior)

Infraorbital artery, inferior ophthalmic vein, infraorbital nerve, zygomatic nerve

Pterygopalatine fossa, infratemporal fossa

Nasolacrimal canal (canalis nasolacrimalis)

Nasolacrimal duct

Nasal cavity

Anterior and posterior ethmoidal foramina (foramen ethmoidale anterius et foramen ethmoidale posterius)

Anterior and posterior ethmoidal arteries, veins and nerves

Nasal cavity

Infraorbital canal (canalis infraorbitalis)

Infraorbital artery, vein and nerve

Facial region

Zygomatico-orbital foramen (foramen zygomaticoorbitale)

Zygomatico-orbital artery and cochlear nerve

Facial region

Supraorbital foramen (foramen supraorbitale)

Supraorbital artery, vein, nerve

Facial region

Dictionary

Orbit

orbit

orbita

orbital opening

aditus orbitae

optic canal

canalis opticus

roof

paries superior

medial wall

paries medialis

lateral wall

paries lateralis

floor

paries inferior

orbital surface of frontal bone

facies orbitalis ossis frontalis

lesser wing of sphenoid bone

ala minor ossis sphenoidalis

orbital plate of ethmoidal bone

lamina orbitalis ossis ethmoidalis

frontal process of maxilla

processus frontalis maxillae

lacrimal bone

os lacrimale

body of sphenoidal bone

corpus ossis sphenoidalis

orbital surface of greater wing of sphenoidal bone

facies orbitalis alae majoris ossis sphenoidalis

orbital surface of zygomatic bone

facies orbitalis ossis zygomatici

orbital surface of maxilla

facies orbitalis maxillae

orbital surface of zygomatic bone

facies orbitalis ossis zygomatici

orbital process of palatine bone

processus orbitalis ossis palatini

superior orbital fissure

fissura orbitalis superior

inferior orbital fissure

fissura orbitalis inferior

nasolacrimal canal

canalis nasolacrimalis

anterior ethmoidal foramen

foramen ethmoidale anterius

posterior ethmoidal foramen

foramen ethmoidale posterius

infraorbital canal

canalis infraorbitalis

zygomaticoorbital foramen

foramen zygomaticoorbitale

supraorbital foramen

foramen supraorbitale