Ocular Kinematics and Muscle Anatomy Flashcards
What is the branch of classical mechanics that describes the motion of points, bodies, and systems of bodies, without consideration of the forces that cause it
kinematics
What does kinematics focus on and exclude?
Focuses on motion, excludes forces
Describe the CN innervation of the 6 EOMS
CN 3 Innervations the superior, inferior, and medial rectus in addition to the inferior oblique; the superior oblique is innervated by CN 4; the lateral rectus is innervated by CN 6
The ____ is not a contractile tissue, but force direction comes from the muscle
superior oblique tendon
Where does the muscle attach to the bony orbit?
origin
Where does the muscle attach to the globe?
insertion
What forms the muscle cone?
The recti muscles, Origin at Annulus of Zinn
What goes thru the SOF and above the Annulus of Zinn?
lacrimal, frontal, trochlear, superior ophthalmic vein
What goes thru the SOF and Annulus of Zinn?
nasociliary, oculomoter superior and inferior, and abducens
What goes thru the optic canal?
optic nerve and ophthalmic artery
What goes thru the IOF?
zygomatic, infraorbital nerve artery and vein, and the inferior ophthalmic vein
What is optic neuritis and what are the signs?
inflammation of the optic nerve; pain on EOMS is a sign, if retrobulbar there is APD
Superior Rectus: innervation, origin, insertion, and fun fact
CN 3; superior annulus of zinn; 23 degree angle w/ primary gaze on superior sclera, 7.4 mm from limbus (furthest); connected sheath w/ levator= coordinated eye movements with eyelids
Superior rectus actions:
elevation, adduction, and intorsion
Inferior Rectus: innervation, origin, insertion, and fun fact
CN 3; inferior annulus of zinn, 23 degree angle w/primary gaze on inferior sclera (6.7 mm from limbus); IR passes of IO and fascia below both contributes to lockwoods ligament
Inferior rectus actions
depression, adduction, extorsion
Lateral Rectus: innervation, origin, insertion, and fun fact
CN 6; upper and lower limb of annulus AND process of greater sphenoid wing; parallel to medial recuts 6.9 mm from limbus; fascial expansion from muscle sheath of lateral check ligament; whitnall’s tubercle has attachment at lateral wall of orbit
Lateral rectus action
abduction
Medial Rectus: innervation, origin, insertion, and fun fact
CN 3; upper and lower annulus AND optic nerve sheath; 5.5 mm from limbus (most anterior); medial check ligament fascial expansion from muscle sheath attaches to medial orbit
Medial rectus action
adduction
What is the spiral of tilleaux?
The nature of insertions of EOMS; medial is most anterior and superior is least anterior; most surgical correction done on medial rectus then lateral rectus
Superior Oblique: innervation, origin, insertion, and fun fact
CN 4; ANATOMICAL origin is lesser wing of sphenoid, PHYSIOLOGICAL origin is cartilaginous trochlea of the superior medial orbital wall (muscle ends before trochlea and tendon passes thru); insertion lateral posterior globe
Superior oblique actions
Intorsion, Abduction, Depression
Explain the three superior oblique vector forces:
primary gaze- straight ahead
adduction- 54 degrees medial
abduction- 36 degrees lateral
