Eye & Eye Movements (Part 1) Flashcards
What bones make up the eye orbit?
Frontal Zygomatic Sphenoid (Greater Wing) Ethmoid Lacrimal Palatine Maxilla
What are the sinuses and their location in relation to the eye orbit?
Frontal Sinus – Superior and Medial
Ethmoid Sinus – Medial
Maxillary Sinus – Inferior and Medial
If there is an infection within the Ethmoid Sinus and it goes to the eye orbit, what can occur?
Optic Neuritis
***This is damage and swelling to the Optic N. (CN II). Ethmoid Sinus is very close to Optic Canal and thus the Optic N.!!!
An orbital ________ fracture is a fracture of the orbital walls usually caused by indirect trauma.
Blowout
In an orbital “blowout” fracture, the “blowout” usually occurs medially and inferiorly involving the _________ bone.
Maxillary
In an orbital “blowout” fracture, orbital contents may prolapse and become entrapped in which sinus?
Maxillary Sinus
What are symptoms of an orbital “blowout” fracture?
Diplopia
Globe Ptosis (eye sinking down into Maxillary Sinus)
Exophthalmos (protrusion of eyeball)
What passes through the Optic Canal?
CN II (Optic N.) Ophthalmic A.
The (LATERAL/MEDIAL) walls of the orbit are nearly parallel to each other, while the (LATERAL/MEDIAL) walls are approximately at right angles to each other.
Medial
Lateral
The orientation of the medial and lateral walls of the orbit cause the axes of the orbit to diverge at ______ and the optical axes (axes of gaze) to be _______.
45 degrees
Parallel
What are the movements of the eye around the three axes?
Vertical Axis – Abduction or Adduction
Horizontal Axis – Elevation or Depression
AP Axis – Intorsion (Medial Rotation) or Extorsion (Lateral Rotation
What nerve opens the eye, and what nerve closes it?
Opens Eye = Facial N. (CN VII) – via Orbicularis Oculi M.
Closes Eye = Oculomotor N. (CN III) – via Levator Palpebrae Superioris M.
***Specifically, it is the Superior branch of CN III
What muscle elevates the eyelid?
Levator Palpebrae Superioris
What is the origin and insertion for the Levator Palpebrae Superioris?
Origin – Lesser Wing of Sphenoid
Insertion – Superior Tarsus and skin of eyelid
What passes through the Inferior Orbital Fissure?
Maxillary N. as it transitions to Infraorbital N.
Zygomatic N.
T/F. The muscles of the eye are oriented based on the Orbital Axis, not the Optical Axis.
True
This muscle is located just inferiorly to Levator Palpebrae Superioris.
Superior Rectus
This muscle is located superiorly and goes through trochlea, which changes the direction of its muscle fibers.
Superior Oblique
This muscle is located inferiorly and attaches anteriorly to posteriorly on the eye.
Inferior Oblique
What are the movements of the Superior Rectus on the horizontal axis?
Elevate eye
What are the movements of the Inferior Rectus on the horizontal axis?
Depress eye
What are the movements of the Superior Rectus on the vertical axis?
Adduct eye
***Because it lies medial to the vertical axis, so it pulls inward
What are the movements of the Inferior Rectus on the vertical axis?
Adduct eye
***Because it lies medial to the vertical axis, so it pulls inward
What are the movements of the Superior Rectus on the AP axis?
Intorsion (medially rotate) eye