Lecture 25 - Orbit II Flashcards
What cranial nerves are in the orbit?
CN II, III, IV, V1, and VI
What is CN II?
Optic
What is CN III?
Oculomotor
What is CN IV?
Trochlear
What is CN V1?
Opthalmic division of Trigeminal
What is CN VI?
Abducens
What travels through the optic canal?
Optic nerve, internal opthalmic artery and vein
What does CN III innervate?
Ventral oblique
V/M/D recti
Levator palpebrae superioris
What does the CN III innervate that is NOT muscle?
Ciliary ganglion
What are the branches of CN III?
Long cililary nn., A/P ethmoidal nn., and short ciliary nn.
What is the function of the long ciliary nn.?
Sensory from cornea and sclera
What is the function of the ethmoidal nn.?
Sensory from nasal cavity
What is the function of the short ciliary?
Parasympathetics to pupillary sphincter and ciliary muscle
Where do the nerves (not CN III) in the ciliary ganglion come from?
Edinger-westphal nucleus - midbrain
Where do the nerves from the ciliary ganglion do?
Pupillary sphincter and ciliary muscles
What does the trochlear n. innervate?
Dorsal oblique m.
What does the abducens n. innervate?
Lateral rectus m.
What are the branches of CN V1 within the orbit?
Nasociliary - Frontal - Lacrimal
What does the nasocillary n. do?
Sensory from nasal cavity, cornea and sclera
What does the frontal n. do?
Sensory from skin of forehead and scalp
What does the lacrimal gland do?
Sensory from lacrimal gland, conjunctiva, and upper eye lid
What are the branches off the nasociliary branch of CN V1?
Long ciliary nn and Ethmodial nn.
What nerve innervates the lacrimal gland?
postganglionic PNS travel from pterygopalatine ganglion
What does the nerve innervating the lacrimal gland travel through?
Orbital fissure
What association do PNS nerves have as they enter the head?
Fibers wrap around vasculature
What is the internal carotid plexus?
SNS pathway to the eye
Where does the internal carotid plexus go?
Dilator pupillae m.
What is the main artery that gives rise to external opthalmic a.?
Maxillary
What artery gives rise to the internal opthalmic a.?
Internal carotid a.
Where is there a connection between the external and internal carotid?
Short ciliary aa. off long ciliary aa.
What branches off the short ciliary aa.?
Retinal aa.
Where does venous drainage from the orbit go?
Cavernous sinus
– or –
Deep facial vein via V/D external opthalmic v.
What muscle adducts the eye?
Medial rectus
What muscle abducts the eye?
Lateral rectus
What does the dorsal rectus do?
Adduct and elevate eye
What does the ventral rectus do?
Adduct and depress eye
What does the ventral oblique do?
Abduct and elevate eye
What does the dorsal oblique do?
Abduct and depress eye
What muscles are involved in looking up?
Dorsal rectus and ventral oblique
What muscles are involved in looking down?
Ventral rectus and dorsal oblique
