Orbit Flashcards
Long axis of the orbit is directed in what 2 directions
Posterior and medially
Anterior opening of the orbit is surrounded by the orbital margin - what is the orbital margin formed by
Frontal and zygomatic bones and maxilla
Walls of the orbit:
- Superior wall separates orbit from?
- Inferior wall separates orbit from?
- Lateral separates orbit from?
- Medial separates orbit from?
- Separates orbit from anterior cranial fossa
- Separates orbit from maxillary sinus
- From middle cranial fossa and temporal fossa
- From ethmoidal air cells
Walls of the orbit:
- Superior wall is formed by?
- Inferior wall is formed by?
- Lateral wall is formed by?
- Medial wall is formed by?
- Orbital plate of frontal bone and lesser wing of sphenoid
- Orbital surfaces of body of maxilla and zygomatic bone/orbital process of palatine
- Orbital surfaces of zygomatic bone and greater wing of sphenoid
- Frontal process of maxilla, lacrimal bone, orbital plate of ethmoid, and a small part of body of sphenoid
Optic canal:
- Opening between what 2 things?
- What nerve and artery does it transmit?
- Opening between 2 roots of lesser wing of sphenoid
2. Optic nerve and ophthalmic artery
Superior orbital fissure:
- Opening between what 2 things?
- Transmits what vein?
- Transmits what 3 nerves
- Transmits branches of what nerve? What 3 branches?
- Greater and lesser wing of sphenoid 2. Superior ophthalmic vein
- CN III, CN IV, and CN VI
- Branches of ophthalmic nerve (V1) - frontal, lacrimal and nasociliary
Inferior orbital fissure:
- Opening between what 2 things?
- Transmits what nerves/vessels (2)
- Transmits vein that communicates between what 2 veins?
- Greater wing of sphenoid and maxilla
- Infraorbital nerve/vessels and zygomatic nerve/veins
- Communicating inferior ophthalmic vein with pterygoid venous plexus
Supraorbital notch (or foramen):
- Located at junction of ?
- Transmits what nerve/vessels
- Medial and middle thirds of superior orbital margin
2. Supraorbital nerve/vessels
Infraorbital groove:
- Location?
- Continuous anteriorly with __, which opens onto face via ?
- These 3 spaces transmit what nerve/vessels
- Floor of orbit
- Infraorbital canal which opens onto face via infraorbital foramen
- Infraorbital nerve/vessels
Fossa for lacrimal sac:
- Depression located where?
- Continuous inferiorly with? (This houses what?)
- Communicates orbit with?
- Anterior part of medial wall of orbit
- Nasolacrimal canal which houses nasolacrimal duct
- Inferior nasal meatus
Anterior and posterior ethmoidal foramina:
- Located along?
- Transmits what nerve/vessels?
- Frontoethmoidial suture
2. Anterior and posterior ethmoidal nerves and vessels
Orbital surface of zygomatic bone:
- __ part of lateral wall of orbit
- Has small openings for canals that transmit what 2 nerves/vessels
- Anterior
2. Zygomaticofacial and zygomaticotemporal nerves/vessels
There are 7 extraocular muscles; 6 move the eyeball, 1 does?
Elevates upper eyelid
Rectus muscles:
- How many are there?
- Origin?
- Insertion?
- Innervation?
- 4 (superior, inferior, lateral and medial)
- Common tendinous ring which surrounds optic canal and inferomedial part of superior orbital fissure
- Into sclera, posterior to corneoscleral junction
- Lateral rectus= abducens nerve; other 3= oculomotor nerve
Levator palpebrae superioris:
- Origin?
- Course?
- Insertion?
- Innervation?
- Action?
- Sphenoid, above optic canal
- Passes forward under orbit roof and ends anteriorly in a broad tendon
- Into superior tarsus and skin of upper eyelid
- Oculomotor
- Elevate upper eyelid
Superior tarsal muscle (of Muller)
- Extends from where to where?
- Innervation
- Action
- Extends from inferior surface of levator palpebrae superioris to superior tarsus
- Sympathetic fibers from superior cervical ganglion
- Elevates upper eyelid
Superior oblique muscle:
- Location
- Origin?
- Course?
- Tendon changes direction and goes where?
- Insertion?
- Innervation
- In superomedial part of orbit
- Sphenoid (superior and medial to optic canal)
- Passes anteriorly and becomes continuous with a tendon, tendon passes thru trochlea attached to anteromedial part of orbital roof
- Passes posteriorly and laterally, under superior rectus muscle
- Into sclera of superior posterolateral aspect of eyeball
- Trochlear nerve