LAB Orbital Contents Flashcards
What muscle does the Trochlear nerve (CN IV) control?
The superior oblique
What eye muscle do the abducens control?
Lateral Rectus
What two muscles are controlled by the sympathetic nervous system?
Dilator pupillae muscle
Superior tarsal muscle
What muscles of the eye are innervated by CN III parasympathetically?
Sphincter pupillae muscle
Ciliary muscle
Where do the Opthalmic veins drain?
Either the sphenoparietal sinus or the cavernous sinus
What is the periorbita?
The periosteal layer of the bone that lines the orbit
What muscle controls the shape of the lens?
The ciliary muscle (CN III)
What envelopes the eye?
The bulbar sheath or fascia
Called Tenon’s capsule
What are the three divisions of the Opthalmic nerve V1 sensory nerve from medial to lateral?
Nasociliary nerve
Frontal nerve (branches into the supratrochlear and supraorbital nerve)
Lacrimal nerve
What does the lacrimal nerve serve?
Upper eyelid and upper forehead
What does the nasociliary nerve serve?
Nasal cavity
Eyeball
Tip of nose
What does the levator palpebrae superioris do?
Elevates the eyelid
Innervated by CN III
What is the superior tarsal muscle (Mullers muscle)?
Smooth muscle that elevates the eyelid
Sympathetic neurons
Where are the cell bodies that control the superior tarsal muscle?
The superior cervical ganglion
Hat nerves branch off of the nasociliary nerve?
The anterior and posterior ethmodial nerves
The long ciliary nerve
What is the Opthalmic artery a branch of?
The internal carotid
Passes with the optic nerve
What ganglion is located on the optic tract and what type of fibers are in it?
The ciliary ganglia of the optic nerve
Carries parasympathetic nerve
What is the only eye muscle that doesn’t originate from the annular ring?
The inferior oblique which takes origin from maxilla
What structures pass through the superior orbital fissure?
Abducens
Occularmotor
Superior Opthalmic vein
Trochlear nerve
What nerve does not pass through the superior orbital fissure?
The optic nerve
What is the optic nerve supplied by?
The central artery of the retina
What is the trochlea?
The pulley through which the superior oblique muscle passes before it connects to the eyeball
How does Horner syndrome happen?
Results from interruption of the sympathetic pathways on the ipsilateral side of either the:
- Cervical sympathetic trunk
- Sympathetic fibers in the spinal cord and brainstem
How does Horner syndrome present?
Ptosis - drooping of the eyelid
Miosis - pupillary constriction
Anhidrosis - absence of sweating
Flushing of the face (vasodilation)
