ORBIT

STEVEN J. ZEHREN, PH.D.

BONY ORBIT

Frontal bone

Lesser wing of sphenoid

Superior orbital fissure

Optic canal

Greater wing of sphenoid

Zygomatic bone

Inferior orbital fissure

Infraorbital groove& foramen

Maxillary bone

Orbital process ofpalatine bone

Fossa of lacrimal sac

Lacrimal bone

Orbital plate of ethmoid bone(lamina papyracea)

Anterior ethmoidal foramen

Posterior ethmoidal foramen

Supraorbital notch (foramen)

RIGHT BONY ORBIT(ANTERIOR VIEW)

Brain Frontal sinus

Ethmoidal cells

Maxillary sinus

RELATIONSHIPS OF BONY ORBIT (CORONAL SECTION)

Nasal septumEthmoidal cells

Sphenoidal sinuses

Brain (in middle cranial fossa)Optic n.

Medial wall of orbit

Temporalis m.(in temporal fossa)

RELATIONSHIPS OF BONY ORBIT(HORIZONTAL SECTION)

EYEBALL

EYEBALL (HORIZONTAL SECTION)

SHEATHS OF THE OPTIC NERVE

Central a. & v. of retina

Pia

Arachnoid

Dura

Subarachnoid space(Intervaginal space)

Optic disc

OPTIC DISC (PAPILLA)

MUSCLES

Cornea

Iris folds

Lens

Sclera

Sphincter m. of pupil(miosis)

Dilator m. of pupil(mydriasis)

Ciliary m.(accommodation)

Ciliary body Fibers of ciliary zonule(suspensory lig. of lens)

INTRINSIC MUSCLES OF EYEBALL

Oculomotor (parasym. root) of ciliary ganglionShort ciliary nn.

Ciliary g.Ciliary m.

Sphincter m. Dilator m.

Lateral horn of T1 – T3cord segments

Sup. cervicalganglion

Int. carotid plexus

V1Long ciliary n.

Sympathetic root of ciliary g.

AUTONOMIC INNERVATION OF THE EYE

Pre-Post-Pre-Post-

Sympathetic

Parasympathetic

Accessory oculomotor (Edinger-Westphal) nucleusin midbrain

POSITION OF CILIARY GANGLION

Ciliary ganglion

Lateral rectus

Optic nerve

Short ciliary nerves

Trochlea (pulley)

Inferior oblique m.

Inferior rectus m.

Lateral rectus m. (cut)

Common annular tendon

Medial rectus m.

Superior rectus m.

Levator palpebrae superioris m.

Superior oblique m.

EXTRINSIC EYE MUSCLES(RIGHT LATERAL VIEW)

ORBITAL AXIS NOT THE SAME AS VISUAL AXIS

ORBITAL AXIS

VISUAL AXIS

MOVEMENTS AROUND THE VERTICAL AXIS

ADDUCTORS ABDUCTORS

Medial rectus

Superior rectus

Inferior rectus

Inferior oblique

Superior oblique

Lateral rectus

MOVEMENTS AROUND THE LATEROMEDIAL (TRANSVERSE) AXIS

ELEVATORS DEPRESSORS

Superior rectus

Inferior oblique

Inferior rectus

Superior oblique

MOVEMENTS AROUND THE A-P AXIS

INTORSION

EXTORSION

Superior rectus

Superior oblique

Inferior rectus

Inferior oblique

INNERVATION OF EXTRINSIC EYE MUSCLES(SO4, LR6, R3)

MUSCLES OF THE UPPER EYELID

Levator palpebrae superioris(striated muscle/oculomotor n.)

Superior tarsal muscle(smooth muscle/sympathetic)

Superior tarsal plate

PERIORBITA & FASCIA

Medial check ligamentLateral check ligament

Periorbita Periorbita

Medial rectus muscle and sheath

Bulbar sheath(Tenon’s capsule) Lateral rectus muscle

and sheath

Orbital fat

PERIORBITA AND FASCIA (HORIZONTAL SECTION)

NERVES

Trigeminal ganglion

Ophthalmic n. (V1)

Nasociliary n.

Supratrochlear n.

Frontal n.

Lacrimal n.

Medial branch

Lateral branchSupraorbital n.

NFL(3 BRANCHES OF V1)

OPHTHALMIC NERVE (V1)

Nasociliary n.

Posterior ethmoidal n.

Anterior ethmoidal n.

Infratrochlear n.

Ophthalmic n. (V1)

Frontal n. (cut)

Lacrimal n.

Long ciliary nn.

OPHTHALMIC NERVE (V1)(DEEP DISSECTION)

VESSELS

Internal carotid a.

Ophthalmic a.

Muscular branch

Continuation of ophthalmic a.

Posterior ethmoidal a.

Anterior ethmoidal a.

Dorsal nasal a.

Supratrochlear a.

Medial palpebral a.

Lateral palpebral a.

Supraorbital a.

Posterior ciliary aa.

Lacrimal a.

Central a. of retina

OPHTHALMIC ARTERY

Supratrochlear v.

Supraorbital v.

Angular v.

Facial v.

Vorticose vv.

Superior ophthalmic v.

Inferior ophthalmic v.

Cavernous sinus

Pterygoid plexus

OPHTHALMIC VEINS

END OF LECTURE