Skull and Orbital Anatomy Flashcards
Try to remember these parts of the skull
Remember this diagram of orbital anatomy
Two bony cavities occupied by the eyes and associated muscles, nerves, blood vessels, etc.
Orbits
Where are the apex and base of the orbit situated?
Apex - Posteriorly
Base - Anteriorly
(Shaped by a 4 sided pyramid)
What structure is at the apex of the “bony pyramid” of the orbital
Optic Foramen
(think, how else do you get optical nerve through?)
Zygomatic process of frontal bone and greater wing of the sphenoid (orbital anatomy)
Lateral Wall
From anterior to posterior, this contains the
maxilla, lacrimal bone, lamina papyracea
Medial Wall
Orbital surfaces of the zygomatic bone and maxilla
Floor
Orbital plate of the frontal bone
Roof
Posterior part of the orbital roof
Carries the optic nerve and ophthalmic artery from the middle cranial fossa
Optic Canal
Structure between the greater and lesser wings of sphenoid bone
Carry CN III, IV, VI
Carries CN V1
Superior Orbital Fissure
Structure between greater sphenoid wing and the maxilla
Carries CN V2
Inferior Orbital Fissure
Gloss over these two diagrams of V1 V2 and V3 nerve distribution
Functions of the Lacrimal Gland
Produces secretions (tears) to lubricate eyes
Drains into the lacrimal duct (this is why your nose is runny when you cry)
Where does the Lacrimal duct lie?
In the Lacrimal Fossa (recess of the frontal bone)
What emerges from the internal carotid artery after the cavernous sinus
Is the only branch of the internal carotid artery
Opthalmic Arter
Remember this diagram of the anatomy of the eye
What part of the eye is responsible for focusing light?
Cornea and Lens
What part of the eye controls how much light reaches the eye?
It also adjusts the size of the pupil
Iris
What part of the eye further focuses light via accomodation?
Lens
What part of the eye converts light to electronic signal?
Retina
Quickly look at optical nerve pathway
How many extraocular muscles are there?
What are they?
7 in total,
4 rectus muscles
1 Levator papebrae suprioris
1 inferior and 1 superior oblique muslces
Which muscle of the eye is responsible for moving it TOWARDS the nose
Medial Rectus
Which muscle of the eye is responsible for moving it AWAY from the nose?
Lateral Rectus
Which muslces of the eye move it up and down
Superior rectus - up
Inferior rectus - down
Which nerve is attached to the Superior Oblique muscle
Which to the Lateral Rectus?
CN IV to superior oblique (Trochlear)
CN VI to lateral rectus (Abducens nerve)
(Everything else is CN III, oculomotor)
What are the three major orbit compartments divided by the muscle cone?
Intraconal
Conal
Extracona
What does the Intraconal compartment hold?
Optic Nerves
Vessels
Fat
What does the conal department hold?
Defined by extraocular muslces
What does the Extraconal compartment hold?
Lacrimal Gland
Fat
Lymphoid tissue
Which bone of the skull has complex inside to let CN VII, VIII and cochlear through?
Temporal Bone
What is a hole in the ocipital bone where brain stem becomes the spinal cord?
Foramen Magnum
What opening do the CN 7 and 8 go through in the temporal bone?
Internal Acoustic modulus
Where does the CN V2 go through?
Inferior orbital fissure after accessing through foramen rotundum
What does the foramen rotundum innervate with?
Mid parts of the face
Try to remember these visual field deficits.
What suture separates the parietal bone from the frontal?
Coronal Suture
