Anatomy of the Orbit

How many axes of motion does the eye have? 3 rotational axes, which is 6 directions

Axes of Motion

Vertical Movement (around transverse axis)

Elevation

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Depression

Horizontal Movement (around vertical axis)

abduction (move eyes away from the nose)

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adduction (move eyes towards the nose)

CW/CCW Movement (around AP axis)

_{^{*when you tilt your head, your eyes tries to follow}}

lateral rotation (extorsion)

_{^{*move eyes away from the nose}}

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medial rotation (intorsion)

_{^{*move eyes towards the nose}}

Superior Rectus

• Elevates the gaze

Intuitive action of extra-ocular muscles

Medial Rectus

• Adducts the gaze

Intuitive action of extra-ocular muscles

Inferior Rectus

• Depresses the gaze

Intuitive action of extra-ocular muscles

_{^{Medial and Lateral rotations (CW, CCW)}}

Trochlea

• Pulley for tendon of superior oblique

Intuitive action of extra-ocular muscles

Superior Oblique

• Medially rotates gaze (intorsion)

  • Depress gaze

  • Abduct gaze

Intuitive action of extra-ocular muscles

Inferior Oblique

• Laterally rotates gaze (extorsion)

  • Elevates gaze

  • Abduct gaze

Intuitive action of extra-ocular muscles

Lacrimal Gland

• Produces lacrimal fluid (tears)

Lacrimal Apparatus

Lacrimal Ducts

• Transfer fluid to conjunctiva

Lacrimal Apparatus

Lacrimal Caruncle

• Tissue in corner of eye helps to form lacrimal lake & a funnel

Lacrimal Apparatus

Lacrimal Canaliculi (S & I)

• Small canals that drain lacrimal lake into lacrimal sac

Lacrimal Apparatus

Lacrimal Sac

• Bag-like upper portion of nasolacrimal duct that conveys fluid from eye to nasal cavity

Lacrimal Apparatus