CHAPTER 21 : The Orbit and Eyeball

Home | OG anatomy | Gross Anatomy | Topic index | Chapter 21



The Orbit

It is shaped like a pear or a four-sided pyramid with the apex situated posteriorly and the base anteriorly.

Orbital Margins and walls

Orbital Margins:

Superior (s): Frontal bone.

Lateral margin (L) : Zygomatic bone.

Inferior margin (I): Zygomatic and maxillary bones.

Medial margin(m): maxilla, lacrimal and frontal bones

Orbital Walls

Roof: Frontal and sphenoid bones

Lateral wall: Zygomatic and Sphenoid bones.

Floor: Maxilla, Zygomatic and palatine bones.

Medial wall: Ethmoid, lacrimal and frontal bones



Orbital Relations and Foramina



Superior: Anterior cranial fossa and frontal sinus(A).

Inferior: Maxillary sinus(B).

Medial: Ethmoid and sphenoid air sinuses(C).

Lateral: Temporal fossa infront and middle cranial fossa behind(D)


Supra orbital supra orbital nerve & vessels
Supra trochlea supra trochlea nerve & svessels
Infra orbital infra orbital nerve & vessels
Superior orbital fissure oculomotor , trochlea, opthalmic, abducens, nerves & opthalmic veins
Inferior orbital fissure maxillary nerve
Optic canal optic nerve, opthalmic artery, central artery of retina