Ocular Anatomy: Bones of the Skull & Orbit Flashcards

Vocabulary flashcards covering the cranial and facial bones, sutures, foramina, paranasal sinuses, connective tissue systems, and orbital wall structures based on lecture notes.

Suture

A firm, fibrous joint between bones, most of which are immovable.

Sinus

An air-filled cavity within bones.

Foramen

An opening, hole, or passage in bone.

Cranial Bones

The $8$ bones of the skull consisting of $(2)$ parietal, $(2)$ temporal, frontal, occipital, sphenoid, and ethmoid bones.

Facial Bones

The $14$ bones of the face consisting of $(2)$ lacrimal, $(2)$ nasal, $(2)$ zygomatic, $(2)$ maxillary, $(2)$ palatine, $(2)$ inferior conchae, vomer, and mandible.

Parietal Bones

The $(2)$ cranial bones forming the roof and sides of the cranium.

Temporal Bones

The $(2)$ cranial bones forming the sides and base of the cranium.

Stylomastoid Foramen

An opening in the temporal bone for the passage of the facial nerve.

Carotid Canal

A passage in the temporal bone for the internal carotid artery.

Frontal Bone

The cranial bone forming the anterior skull and superior part of the face.

Supraorbital Notch / Foramen

An opening in the frontal bone for supraorbital vessels and nerves.

Supratrochlear Notch / Foramen

An opening in the frontal bone for supratrochlear vessels and nerves.

Fossa for Lacrimal Gland

A temporal depression located in the frontal bone where the lacrimal gland sits.

Occipital Bone

The cranial bone forming the posterior skull and floor of the cranium.

External Occipital Protuberance (Inion)

A bony projection at the back of the skull serving as an attachment point for connective tissue.

Foramen Magnum

A passageway for the spinal cord located at the base of the occipital bone.

Sagittal Suture

The cranial suture joining parietal bone + parietal bone.

Coronal Suture

The cranial suture joining parietal bone + frontal bone.

Lambdoidal Suture

The cranial suture joining parietal bone + occipital bone.

Squamosal Suture

The cranial suture joining parietal bone + temporal bone.

Optic Canal / Foramen

An opening in the lesser wing of the sphenoid bone for the optic nerve and ophthalmic artery.

Foramen Rotundum

An opening in the greater wing of the sphenoid bone for the maxillary nerve.

Foramen Ovale

An opening in the greater wing of the sphenoid bone for the mandibular nerve.

Foramen Spinosum

An opening in the greater wing of the sphenoid bone for the middle meningeal artery.

Sella Turcica (Pituitary Fossa / Hypophyseal Fossa)

A depression in the body of the sphenoid bone that houses the pituitary gland.

Superior Orbital Fissure (SOF)

An opening between the greater and lesser wings of the sphenoid bone located between the orbital roof and lateral orbital wall, posterior to the common tendinous ring.

Inferior Orbital Fissure (IOF)

An opening between the greater wing of the sphenoid bone and the maxilla, positioned between the orbital floor and lateral orbital wall.

"NOA" Nerves

Nerves passing through both the Superior Orbital Fissure and the Common Tendinous Ring: Nasociliary nerve, Oculomotor nerve, and Abducens nerve.

"LOFT" Structures

Vessels and nerves passing through the Superior Orbital Fissure above the Common Tendinous Ring: Lacrimal nerve, Superior ophthalmic vein, Frontal nerve, and Trochlear nerve.

"OZII" Structures

Vessels and nerves passing through the Inferior Orbital Fissure: Inferior ophthalmic vein, Zygomatic nerve, Infraorbital nerve, and Infraorbital artery and vein.

Ethmoid Bone

A cranial bone forming bony areas of the nasal cavity and medial orbital walls.

Cribriform Plate

The flat portion of the ethmoid bone with cribriform foramina for the passage of olfactory nerves.

Lacrimal Bones

The $(2)$ smallest facial bones located medially that support the lacrimal apparatus within the orbit.

Zygomatic Bones

The $(2)$ facial bones forming the lateral cheekbone and articulating with the zygomatic process of the frontal bone.

Whitnall Tubercle (Lateral / Marginal Orbital Tubercle)

A small prominence $\sim 2-3\,mm$ posterior to the orbital rim on the zygomatic bone that acts as an attachment site for orbital connective tissue structures.

Maxillae

Paired facial bones forming the upper jaw, hard palate, lateral walls of the nasal cavity, and floor of the orbit.

Lacrimal Fossa

A depression within the medial orbital wall that contains the nasolacrimal sac.

Anterior Lacrimal Crest

The anterior boundary of the lacrimal fossa, formed by the maxillary bone.

Posterior Lacrimal Crest

The posterior boundary of the lacrimal fossa, formed by the lacrimal bone.

Palatine Bones

Paired L-shaped bones extending from the hard palate through the nasal cavity to the orbital floor.

Inferior Conchae

Paired scroll-like bones located along the lateral walls of the nasal cavity.

Vomer

A single facial bone forming the posterior part of the nasal septum.

Mandible

A horseshoe-shaped bone forming the movable lower jaw, consisting of a body and two rami.

Paranasal Sinuses

Four pairs of mucosa-lined, air-filled cavities surrounding the orbits: Frontal, Ethmoid, Sphenoid, and Maxillary (largest).

Orbital Cellulitis

A serious medical emergency involving rapid spread of infection beyond the orbital septum into orbital contents, often secondary to sinusitis.

Intraconal Compartment

The space within the muscle cone containing the optic nerve, ophthalmic artery, central retinal artery and vein, and adipose tissue.

Extraconal Compartment

The space outside the muscle cone containing the lacrimal gland, adipose tissue, and nerves.

Periorbita (Orbital Fascia)

A dense connective tissue layer covering and lining orbital bones and glands, continuous with facial periosteum and dural layers.

Orbital Septum (Palpebral Fascia)

A thin sheet of fibrous connective tissue embedded within eyelids that encases orbital margins, maintains fat, and acts as a barrier to infection.

Tenon's Capsule

A dense sheet of connective tissue encasing the globe to act as a barrier preventing orbital infections from spreading to the globe.

Sub-Tenon's Space

A potential space between episclera and Tenon's capsule allowing smooth eye movements and serving as a site for medication or anesthetic injections.

Suspensory Ligament of Lockwood

A hammock-like sheet of dense connective tissue located inferior to the globe, attaching to the lacrimal bone medially and zygomatic bone laterally.

Medial Canthal Tendon (Palpebral Ligament)

Connective tissue located anterior to the orbital septum that attaches tarsal plates to the medial orbital margin and anterior lacrimal crest.

Lateral Canthal Tendon (Palpebral Ligament)

Connective tissue located posterior to the orbital septum that attaches tarsal plates to the lateral orbital margin at the lateral orbital tubercle.

Medial Check Ligament

A sheath extension originating at the medial rectus muscle and inserting at the lacrimal bone to stabilize the globe medially.

Lateral Check Ligament

A sheath extension originating at the lateral rectus muscle and inserting at the lateral orbital tubercle to stabilize the globe laterally.

Whitnall Ligament (Superior Transverse Ligament)

A fibrous condensation of orbital fascia extending from the trochlea to the lateral orbital wall that provides upper eyelid support and serves as a levator muscle pulley.

Orbital Roof

A triangular wall composed of the orbital plate of the frontal bone and lesser wing of the sphenoid bone ("FRONT LESS").

Orbital Floor

A triangular wall composed of the orbital plates of the maxillary and zygomatic bones and the orbital process of the palatine bone ("My PAL gets his Zs on the FLOOR").

Orbital Blow-Out Fracture

A fracture commonly involving the thin orbital floor secondary to increased intraorbital pressure from blunt-force injury.

Medial Orbital Wall

A rectangular, thinnest orbital wall composed of the Sphenoid, Maxillary, Ethmoid, and Lacrimal bones ("SMEL").

Lamina Papyracea

The paper-thin orbital plate of the ethmoid bone that forms most of the medial orbital wall.

Lateral Orbital Wall

A triangular, strongest, and most exposed wall of the orbit composed of the Zygomatic bone and Greater wing of the sphenoid bone ("GREAT Z").