The Extraocular Muscles Flashcards
What is Diplopia
Double vision
What is the vestibular apparatus important for
Balance and detecting movement of the head
How many muscles control the movement of the eyes
7 muscles
What are conjugated movements of the eye
Coordinated movements of both eyes allowing us to form 1 image
What muscle lifts the upper eyelid
Levator palpabrae superioris
What 6 muscles work to move the eye
Medial rectus
Lateral rectus
Superior rectus
Inferior rectus
Superior oblique
Inferior oblique
What 3 cranial nerves are involved with the movement of the eye
Oculomotor
Trochlear
Abducens
What nerve innervates the superior oblique
The trochlear
What nerve innervates the lateral rectus
The Abducens
What does the oculomotor nerve innervate
Levator palpabrae superioris
Medial rectus
Superior rectus
Inferior rectus
Inferior oblique
Where do the muscles that move the eyeball originate
All muscles that move the eyeball originate from the orbital bones around the eye
Where do the muscles that move the eyeball insert
They all insert into the sclera
Where does the levator palpebrae superioris insert
Into the upper lid
What is the role of the levator palpebrae superioris
Elevates the upper eye lid
What is ptosis
Drooping of the eye lid
What cranial nerve is the oculomotor nerve
The 3rd cranial nerve
What is the role of the medial rectus
Moves the eye medially (adducts the eye)
What is the role of the lateral rectus
Moves the eye laterally (abducts the eye)
What cranial nerve is the abducens
6th cranial nerve
What is the role of the superior rectus
Primary- elevates the eye
Secondary- adducts and medially rotates
What is the role of the inferior rectus
Primary- depresses the eye
Secondary- adducts and laterally rotates
What is the role of the superior oblique
Primary- medially rotates the eye
Secondary- depresses and abducts
What cranial nerve is the trochlear nerve
The 4th cranial nerve
What is the role of the inferior oblique
Primary- laterally rotates the eye
Secondary- elevates and abducts
What does the inner ear contain
Cochlear
Vestibular apparatus
What is the cochlear important for
Sound
What is the vestibular apparatus important for
Balance
What are the structures involved in the vestibular apparatus
Utricle
Saccule
3 semicircular ducts
What do the semicircular ducts contain
They contain sense organs for balance
What is endolymph
The fluid found in the semicircular ducts in the inner ear
Where do the semicircular ducts empty into
The utricle
What is the role of the semicircular ducts
They detect movements of the head
Where are vestibular nuclei located
In the brainstem
Signals received to the vestibular nuclei control what
Posture
Balance
Conscious awareness of position
What cranial nerves are connects to the vestibular nuclei
Cranial nerve 3
Cranial nerve 4
Cranial nerve 6
What is the oculocephalic reflex
This is maintaining a fixed gaze when the head is moving
