Objective 3 Flashcards
Name the Cranial nerves responsible for innervation of extraocular muscles?
LR6 SO4 3 Oculomotor (3) Trochlear (4) Abducens (6)
What extraocular muscle is responsible only for the adduction of an eye?
Medial Rectus
The lateral rectus muscle is innervated by which cranial nerve?
Abducens CN VI
Which extraocular muscle passes through a U-shaped piece of cartilage called the Trochlea and which is attached to the orbital plate of the frontal bone?
Superior Oblique
What is the term for movement of the eye so that the 12:00 position on the cornea rotates outward away from the nose?
Extorsion
Which extraocular muscle stays in contact with the levator palpabrae superioris muscle for much of its length, allowing for coordination of eye movement with the position of the eyelid?
Superior Rectus
What is the difference between saccadic and pursuit eye movements?
Saccadic movements are quick and sudden.
Pursuit movements follow a slow moving target.
Which of the two extraocular muscles do not have secondary actions?
Lateral Rectus, Medial Rectus
If a person is gazing upward at the sky, which extraocular muscle is being used and what secondary actions are taking place in that mucsle?
Superior Rectus
Intorsion and Adduction
Which extraocular muscles originate in the circle of connective tissue, close to the optic foramen called annulus of Zinn
Rectus muscles
Which extraocular muscle is responsible for elevation, abduction and extorsion?
Inferior oblique
Which of the extraocular muscles is the largest and why is it considered likely the largest?
Medial rectus
Its frequency of use in convergence of the eyes inward wehen reading or when other close work is done.
An abnormality in what nerve can cause: Ptosis—a drooping upper lid; strabismus and double vision; abnormally dilated pupil
CNIII Oculomotor
An abnormality in what nerve can cause: double vision (superior oblique muscle)
Trochlear
CN IV
An abnormality in what nerve can cause: double vision (lateral rectus muscle)
Abducens CN VI
