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Flashcards in Orbit and Eye Deck (34):

Bones of Orbit

  1. Frontal 
  2. Zygyomatic
  3. Maxillary
  4. Lacrimal
  5. Ethmoid 
  6. Palatine
  7. Sphenoid 

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Structures passing through Optic Canal

  1. CN II
  2. Opthalmic artery 


Structures through Superior Orbital Fissure

  1. CN III
  2. CN IV
  3. CN V1
  4. CN VI


Structures through Inferior orbita fissure & infraorbital groove

  1. Infraorbital nerve
  2. Infraorbital vessels 


Strucutres through Anterior & Posterior Ethmoidal Foramina

  • Ant/Post ethmoidal nerves
  • Ant./Post Ethmoidal vessels 


Components of Eyelid

  • Skin
  • Subcutaneous tissue
  • Levator Palpebrae Superioris
  • Orbital Septum
  • Tarsus
    • contain Meibomian (tarsal) glands 
    • superior/inferior tarsus muscle
  • Conjunctiva
    • Thin membrane covering inner eyelid 

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Branches of V1

  • Frontal
  • Supratrochlear
  • Supraorbital 
  • Lacrimal 

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Terminal ganglion of V1 and location 

Gasserian/Semi-lunar ganglion in Meckel's Cave


Pathway of tears from lacrimal gland 

Lacrimal glands-->surface of cornea-->lacrimal canaliculi --> lacrimal sac--> nasolacrimal duct 

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Innervation of Lacrimal Gland

  • General Sensory 
    • Lacrimal Nerve (Branch of V1)
  • Parasympathetic
    • Greater Petrosal Nerve (branch of VII) via V1 
  • Sympathetic 
    • Deep Petrosal Nerve  (branch of Carotid Plexus) via V1


Path of parasympathetic innervation of Lacrimal Gland

VII --> Greater Petrosal Nerve --> Pterygoid canal --> Pterygopalatine ganglion --> Zygomaticotemporal nerve of V2 --> Lacrimal nerve of V1 ---> Lacrimal Gland

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Path of Sympathetic Innervation of Lacrimal Gland 

Carotid Plexus --> Deep Petrosal nerve --> pterygoid canal --> pterygoid ganglion --> Zygomaticotemporal nerve of V2 --> Lacrimal Nerve of V1 --> Lacrimal Nerve of V1

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Branches of V1 Nerve

  • Frontal
  • Supratrochlear
  • Lacrimal
  • Supraorbital
  • Nasociliary Nerve 


Branches of Nasociliary Nerve 

  • Long ciliary
  • Short Ciliary
  • Anterior ethmoidal
  • Posterior ethmoidal
  • Infra-trochlear 

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Optic Nerve (II)

  • Origin: Lateral Geniculate Body
  • Course: Left and Right Optic Tracts cross and travel through optic canal 
  • Components: Special Sensory 
  • Ganglion: "Ganglion cells" of Retina (cell bodies here)`a
  • Function: Vision 

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Incyclotorsion  and what mediated by

Depression, abduction, and medial rotation 

  • Mediated by Superior Oblique 


Excyclotorsion and mediated by what muscle 

Elevation, abduction, lateral rotation 

  • Mediated by Inferior Oblique


Superior Rectus

  • Elevation and Adduction 
  • Innervated by III (Superior division)

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Inferior Rectus

  • Depression and Adduction 
  • Innervated by III (Inferior division)

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Superior Oblique 

  • Depression and Abduction 
  • Incyclotorsion 
  • Innervated by IV (Trochlear)
  • Goes through Trochlea (pulley system)

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Inferior Oblique

  • Elevates and Abducts 
  • Innervated by III (Inferior division)
  • Excyclotorsion 

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Lateral Rectus

  • Abducts eye
  • Innervated by VI (Abducens)


Medial Rectus 

  • Adducts eye
  • Innervated by III (Inferior division)


Levator Palpebrae Superioris

  • Elevates eyelid
  • Innervated by III (Superior Division)


Occulomotor Nerve (III)

Origin: Oculomotor nucleus (Somatic Motor)  & E-W nucleus (para visc. motor)

Course: Post. Cranial foss --> mid cranial fossa --> Cavernous sinus -->superior orbital fissure

Branches: Superior & Inferior Division 

Components: Somatic motor & parasympathetic 

Ganglion: Ciliary 

Distribution: All eye muscles except Superior Oblique and Lateral Rectus

Function: eye movements, 2 smooth muscles 

***sympathetics from symp. trunk travel w/ III to reach eye 

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What nerve and type of nerve synapses in cilliary ganglion?

Parasympathetic of III

  • all other nerves pass through cilliary ganglion but do not synapse 

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Trochlear Nerve (IV)

Origin: Trochlear Nucleus

Course: Middle cranial fossa --> Cavernous sinus --> Superior orbital fissure

Components: Somatic motor

Ganglion: [NONE]

Distribution: Superior Oblique muscle

Function: Eye movement

****is only cranial nerve to emerge from brainstem...longest intracranial course and susceptible to damage from blunt trauma 

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Abducens (VI)

Origin: Pons

Course: Post. cranial fossa --> middle cranial fossa --> cavernous sinus --> SOF

Components: Somatic Motor 

Ganglion: [NONE]

Distribution: Lateral Rectus Muscle

Funciton: Eye movement 

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Structures of Superior Orbital Fissure

  • Outside Tendinous Ring (Made by eye muscles)...LOFT
    • Lacrimal of V1
    • Opthalmic vein 
    • Frontal of V1
    • Trochlear (III)
  • Inside Tendinous RIng...NC 36
    • IV
    • VI
    • Nasocilliary of V1

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Layers of Eyeball

  • Outer Layer
    • Sclera
    • Cornea 
  • Middle Layer
    • Choroid 
    • Cilliary Body
      • adjusts shape of lens
    • Iris 
  • Retina

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Chambers of Eyeball

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  • Optic Disc
    • location where blood vessels leave retina
    • blind spot; not rods/cones there
    • lighter than surrounding retina
  • Macula lutea
    • thinnest area of retina
    • few rods, more cones
    • highly sensitive to light
    • "yellow spot"

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Intrinsic Muscles of the Eye

  • Ciliary Muscle
    • Constricts cilliary body
    • Innervated by III
  • Spincter pupillae
    • circularly arranged 
    • innervated by III
    • constricts pupil
  • Dialator pupillae
    • radially arranged
    • innervated by sympathetics
    • dilates pupil

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