Sutures are named after the bones that they connect, so let’s look at the orbit and name them one by one, just like they do in anatomical textbooks. As we know, the articulations of the bones of the skull are immobile fibrous joints called sutures. Rather than purely memorizing their names, let’s explain the logic here. Fun fact: the word trochlea comes from the Greek word for pulley.Īrticulations of the orbit are not often discussed. It is a pulley-like structure in the orbit through which the tendon of the superior oblique muscle passes. ![]() The trochlea is the only cartilage found in the orbit. The ethmoidal foramina are found at the junction between the roof and the medial wall as a part of the fronto-ethmoidal suture, and serve as the passageways for the anterior and posterior ethmoidal nerves and vessels. Want to learn anatomy faster? Try out our free anatomy quizzes and guides!īesides the lacrimal groove, important landmarks are the anterior and posterior ethmoidal foramina and the trochlea. Posterior to the ethmoid bone, the medial wall is completed by a small portion of the lesser wing of the sphenoid bone that forms the medial part of the optic foramen (canal). ![]() The lacrimal bone and the frontal process of the maxilla build the lacrimal groove which contains the lacrimal sac. Anterior to the ethmoid bone is the lacrimal bone, and anterior to the lacrimal bone is the frontal process of the maxilla. This is the part of the ethmoid bone that contains ethmoidal cells and is very thin. ![]() The majority of the wall is made out of the orbital plate of the ethmoid bone, which is located posterosuperiorly on the wall. The only important landmark of this wall is the anterolaterally located depression called the lacrimal fossa, intended for hosting the orbital part of the lacrimal gland. The largest contributor of the roof is the orbital part of the frontal bone, while the small posterior portion is completed by the lesser wing of the sphenoid bone. The roof, or superior wall, of the orbit separates the orbit from the anterior cranial fossa. Lateral margin – the zygomatic process of the frontal bone and the zygomatic bone.Infra-orbital margin – the zygomatic process of the maxilla and the zygomatic bone.Medial margin – the frontal process of the maxilla.Supra-orbital margin – the frontal bone.The margin has a quadrangular shape, with the following borders: Its function is to protect the contents of the orbit and to provide an attachment site for the orbital septum. The base of the orbit is called the orbital margin or orbital rim. The optic foramen provides passage for the optic nerve (CN II) and ophthalmic artery to exit the skull. It is medial to the superior orbital fissure. The apex of the orbit is the optic foramen (canal), bound medially by the body of the sphenoid bone and laterally by the lesser wing of the sphenoid bone. Finally, a few words about the most common pathological conditions related to the orbit will be discussed. This article will discuss the bones of the orbit, their articulations, and the most important anatomical landmarks. ![]() Orbital fractures, inflammatory and neoplastic processes Optic foramen (canal), lacrimal fossa, lacrimal groove, anterior and posterior ethmoidal foramina, trochlea, superior and inferior orbital fissuresĮyeballs, orbital fascia, orbital fat, extraocular muscles, neurovasculature, lacrimal apparatus Medial: orbital plate of the ethmoid bone, lacrimal bone, frontal process of the maxilla, lesser wing of the sphenoid boneįloor (inferior): orbital surface of the maxilla, zygomatic bone, palatine boneįrontomaxillary, zygomaticomaxillary, frontozygomatic (or zygomaticofrontal), fronto-ethmoidal, sphenofrontal (or frontosphenoidal), sphenozygomatic, frontolacrimal, spheno-ethmoidal, lacrimomaxillary Roof (superior): orbital part of the frontal bone, lesser wing of the sphenoid bone Lateral margin: zygomatic process of the frontal bone and the zygomatic bone and its frontal process Infra-orbital margin: zygomatic process of the maxilla and the zygomatic bone Medial margin: frontal process of the maxilla Many Friendly Zebras Enjoy Lazy Summer Picnic Maxilla, Frontal bone, Zygomatic bone, Ethmoid bone, Lacrimal bone, Sphenoid bone, and Palatine bone The bones that make up the orbit contain several foramina and fissures through which important neurovascular structures (such as the optic nerve (CN II)) pass through on their way from the brain to the eye and face and vice versa. The cavity surrounds and provides mechanical protection for the eye and soft tissue structures related to it. By definition, the orbit (bony orbit or orbital cavity) is a skeletal cavity comprised of seven bones situated within the skull.
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