BCSC 2 : Fundamentals Flashcards
Orbital volume?
30cm3
Orbital entrance dimensions?
35mm (H) x 45mm (W)
Orbit: Location of maximum width?
1cm behind the anterior margin
Depth of the orbit?
40 to 45mm from the orbital entrance to the orbital apex
Bones that make up the bony orbit?
7 bones
- frontal bone
- zygomatic bone
- maxilla
- ethmoid bone
- sphenoid bone
- lacrimal bone
- palatine bone
Orbital margin?
Quadrilateral spiral
- superior margin : frontal bone
- medial margin : frontal bone - anterior lacrimal crest of the maxillary bone - posterior lacrimal crest of the lacrimal bone
- inferior margin : maxillary - zygomatic bone
- lateral margin : zygomatic - frontal bone
Orbital roof?
Orbital plate of the frontal bone - lesser wing of the sphenoid bone
Trochlear fossa location & insertion site of?
Medially, on the frontal bone, 4mm from the orbital margin
Site of the pulley of the SO muscle, the trochlea, a plate of hyaline cartilage is attached
Medial orbital wall?
4 bones
- frontal process of maxillary bone
- lacrimal bone
- orbital plate of the ethmoid bone
- lesser wing of the sphenoid bone
Orbital floor?
3 bones
- maxillary bone
- palatine bone
- orbital plate of the zygomatic bone
Which EOM does not originate from the orbital apex?
IO muscle
Which orbital wall is the thickest and strongest?
Lateral wall
Lateral wall?
2 bones
- zygomatic bone
- greater wing of the sphenoid bone
Lateral orbital tubercle (Whitnall tubercle) : location and site of attachment of which structures?
Small elevation of the orbital margin of the zygomatic bone, 11mm below frontozygomatic suture
Site of attachment of :
- ligament of lateral rectus muscle
- suspensory ligament of the eyeball (Lockwood)
- lateral palpebral ligament
- aponeurosis of the levator palpebrae superioris muscle
- whitnall ligmament
Optic foramen contents?
Passes through the lesser wing of the sphenoid bone
- Optic nerv
- Ophtalmic artery
- Sympathic fibers from the carotid plexus
