What is the function of the lacrimal gland
• Lacrimal gland → secretes lacrimal fluid (saline + lysozyme); moistens/lubricates conjunctiva + cornea; excess = tears
What is the lacrimal gland innervated by
facial nerve (greater petrousal nerve)
What is the drainage pathway of tears
across cornea -> lacrimal puncta -> cannaliculi -> lacrimal sac → nasolacrimal duct → inferior nasal meatus → nasal cavity floor → nasopharynx → swallowed
Which muscles are in the eye and their function
sphincter papillae (constricts pupil - miosis), dilator papillae (dilates pupil)
What supplies the retina
central retinal artery
Origin insertion action and innervation levator palpebae superior is
o = Lesser wing of sphenoid bone, superior and anterior to optic canal
i = Superior tarsus and skin of superior eyelid
Oculomotor nerve (CN III)
Elevates superior eyelid
Origin, insertion action innervation superior oblique
o = Body of sphenoid bone
i = Its tendon passes through a fibrous ring or trochlea, changes its direction, and inserts into sclera deep to superior rectus muscle.
Trochlear nerve (CN IV)
Abducts, depresses, and intorsion
Origin insertion action innervation inferior oblique
o = Anterior part of floor of orbit
i = Sclera deep to lateral rectus muscle
Oculomotor nerve (CN III)
Abducts, elevates, and extorts eyeball
Origin insertion action innervation superior rectus
o = Common tendinous ring
i = Sclera just posterior to corneoscleral junction
Oculomotor nerve (CN III)
Elevates, adducts, and intorts
Origin insertion innervation action of inferior rectus
o = Common tendinous ring
i = Sclera just posterior to corneoscleral junction
Oculomotor nerve (CN III)
Depresses, adducts, and extorts
Origin insertion action innervation of medial rectus
o = Common tendinous ring
i = Sclera just posterior to corneoscleral junction
Oculomotor nerve (CN III)
Adducts eyeball
Origin insertion action innervation lateral rectus
o = Common tendinous ring
i = Sclera just posterior to corneoscleral junction
Abducent nerve (CN VI)
Abducts eyeball
What are the 3 main branches of the ophthalmic division of trigeminal and what do they supply
frontal -> supratrochlear and supraorbital = sensory innervation to forehead
nasocilary:
- long ciliary = sensory tocornea, iris and ciliary body
- posterior ethmoidal = sensory to sphenoidal sinus and posterior ethmoidal air cells
- anterior ethmoidal nerve = external nasal (skin of nose), sensory to nasal lateral wall
- infratrochlear = skin of medial eyelid and root of nose
lacrimal = skin to lateral upper eyelid
What is the arterial supply of the orbit
opthalmic artery, infraspinatus-orbital (floor structures) and central retinal
What are the branches of the opthalmic artery and what do they supply
• Supra-orbital → forehead + scalp
• Supratrochlear → forehead + scalp
• Lacrimal → lacrimal gland, conjunctiva, eyelids
• Dorsal nasal → surface of nose
• Short posterior ciliaries → pierce sclera near optic nerve → supply choroid (cones + rods)
• Long posterior ciliaries → pierce sclera → supply ciliary body + iris
• Posterior ethmoidal → posterior ethmoidal cells
• Anterior ethmoidal → anterior cranial fossa, ethmoidal cells, frontal sinus, nasal cavity, dorsum of nose skin
• Anterior ciliary → muscular branches (recti) → pierce sclera → networks in iris + ciliary body
What is the infra orbital artery a branch of
maxillary branch) → infra-orbital groove/foramen → face
What is the opthalmic artery a branch of
ICA
Which veins pass through the superior orbital fissure
superior and inferior opthalmic
What is the course of the oculi motor nerve CN III
• Midbrain -> cavernous sinus -> Enters through superior orbital fissure
• Passes into orbit to innervate EO muscles and the pupil
• Somatic motor to EO muscles (IO, IR, MR, SR, LPS)
• Visceral motor to pupillary constrictor and cilliary muscles
What is the course of CNIV trochlear nerve
• Midbrain -> cavernous sinus -> superior orbital fissure
• Superior oblique muscle (wraps arounf trochlear)
• Wraps oblique above eye
What is the course of CNVI abducens
• Pons -> supeiror orbital fissure
• Lateral rectus muscle
