By Dr.Faris Muhammed Al-Haddad A Lecturer at Medical College / Hawler Medical University Arbil / Iraq

1. ORBIT, EYE & LACRIMAL APPARATUS
PART-I
BY
LECTURER
FARIS MUHAMMED AL-HADDAD
M.B.CH.B, F.I.B.M.S ( ANATOMY )
DEPARTMENT OF ANATOMY, COLLEGE OF MEDICINE,
HAWLER MEDICAL UNIVERSITY

2. ORBIT & EYE
• THE EYE IS THE ORGAN OF VISION &
THE PRINCIPLE COMPONENT OF THE
VISUAL APPARATUS.
• THE EYE IS LODGED IN THE ORBIT,
TOGETHER WITH THE EXTRAOCULAR
MUSCLES WHICH MOVE THE EYE,
NERVES, LACRIMAL GLAND, FASCIA AND
FAT.

3. BONY SKELETON OF THE ORBIT

4. THE ORBIT
• A PYRAMIDAL BONY CAVITY
Its lying on its side, having :
1. Apex : is at the back
2. Base : forming the orbital margin
on the front of the facial skeleton

5. ORBITAL MARGIN BONES
SUPERIOR
FRONTAL BONE
LATERAL PROCESSES OF FRONTAL
& ZYGOMATIC BONES
INFERIOR ZYGOMATIC & MAXILLARY BONES
MEDIAL PROCESSES OF FRONTAL & MAXILLARY BONES

6. ORBITAL WALL BONE
ROOF
FRONTAL BONE
(ORBITAL PLATE)
LATERAL
1. ZYGOMATIC BONE
2. SPHENOID BONE
(GREATER WING)
FLOOR MAXILLARY BONE
(ORBITAL PLATE)
MEDIAL
(FROM BEFORE
BACKWARDS)
1. MAXILLARY BONE (FRONTAL PROCESS)
2. LACRIMAL BONE
3. ETHMOID BONE (ORBITAL PLATE)
4. SPHENOID BODY

7. OPENINGS IN THE ORBIT POSITION TRANSMITS
ORBITAL OPENING ANTERIORLY 1/6TH OF EYES ARE EXPOSED
SUPRAORBITAL NOTCH
( OR FORAMEN )
SUPRAORBITAL MARGIN SUPRAORBITAL N. & B.V.s
INFRAORBITAL GROOVE
& CANAL
ORBITAL PLATE OF MAXILLA
( FLOOR OF ORBIT )
INFRAORBITAL N.
( A CONOTINUATION OF MAXILLARY N. )
& B.V.s
NASOLACRIMAL CANAL
ANTERIORLY ON MEDIAL
WALL OF ORBIT
NASOLACRIMAL DUCT TO THE INFERIOR
MEATUS OF THE NOSE

8. OPENINGS IN THE
ORBIT
POSITION
TRANSMITS
INFERIOR ORBITAL
FISSURE
POSTERIORLY BETWEEN :
• MAXILLA
• GREATER WING OF
SPHENOID
• MAXILLARY N. & ITS ZYGOMATIC BR.
• INFERIOR OPHTHALMIC VEIN
• SYMPATHETIC N.s
( IOF COMMUNICATES WITH PTERYGO –
PALATINE FOSSA)
OPTIC CANAL
POSTERIORLY IN :
• LESSER WING OF
SPHENOID
• OPTIC N.
• OPHTHALMIC A.
(THIS CANAL CMMUNICATES WITH MIDDLE CRANIAL
FOSSA)

9. OPENING IN
THE ORBIT
LOCATION TRANSMITS
SUPERIOR
ORBITAL
FISSURE
POSTERIORLY
BETWEEN :
• GREATER WING
• LESSER WING
OF SPHENOID
UPPER LATERAL PART ABOVE
TENDENOUS RING :
• LACRIMAL N.
• FRONTAL N.s
• 4TH C.N.
• SUPERIOR OPHTHALMIC VEIN
MIDDLE PART THROUGH THE
RING :
• UPPER DIVISION OF 3RD C.N.
• NASOCILIARY N.
• LOWER DIVISION OF 3RD C.N.
• ABDUCENT N.
LOWER MEDIAL PART BELOW THE
TENDENOUS RING :
• INFERIOR OPHTHALMIC VEIN

10. FASCIA OF THE ORBIT

11. ORBITAL FASCIA
• IS PERIOSTEUM
• LOOSELY ATTACHED TO BONES
• CONTINUOUS THROGH THE OPENINGS & FISSURE WITH PERIOSTEUM
COVERING OTHER BONES
• ORBITALIS MUSCLE : IS A THIN LAYER OF SMOOTH M., THAT BRIDGES
THE INFERIOR ORBITAL FISSURE, IS OF UNKNOWN FUNCTION.

12. FASCIAL SHEATH OF THE EYEBAL *
• SURROUND EYE BALL FROM
OPTIC N. TO CORNEOSCLERAL
JUNCTION
• SEPARATES EYEBALL FROM
SURROUNDING FAT
• PROVIDES A SOCKET FOR FREE
MOVEMENT
• PERFORATED BY TENDONS OF
OCULAR M.s & ENSHEATHES
THESE M.s
*

13. • THE SHEATHES OF THE MEDIAL & LATERAL RECTI
ARE ATTACHED TO THE MEDIAL & LATERAL
WALLS OF THE ORBIT BY THE TRIANGULAR
MEDIAL & LATERAL CHECK LIGAMENTS
• THE LOWER PART OF THE SHEATH WHICH PASSES
BENEATH THE EYEBALL & CONNECTING CHECK
LIGAMENTS IS THICKENED & SUSPENDS THE
EYEBALL, ITS CALLED SUSPENSORY LIGAMENT OF
THE EYE

14. NEUROVASCULATURE OF THE ORBIT

15. NERVE OF
ORBIT
ENTERS
ORBIT
THROUGH
ORIGIN COURSE IN ORBIT ACTION NOTES
OPTIC N. OPTIC
CANAL
RETINAL
GANGLION
CELLS
• OPHTHALMIC A. : FIRST
LATERAL TO OPTIC N.,
THEN CROSS OVER IT FROM
LATERAL TO MEDIAL
• OPTIC N. RUNS ANTERO -
LATERALLY WITHIN CONE
OF RECTI M.s
• OPTIC N. PEIRCES SCLERA
MEDIAL TO POSTERIOR EYE
POLE
• OPTIC N. IS SURROUNDED
BY THE THREE MENINGIES,
SO C.S.F. IN THE SUBARACH-
NOID SPACE REACHES AS
FAR AS THE SCLERA.
CONVEYS
VISUAL
INFORMA -
TION FROM
EYES
A RISE IN C.S.F.
PRESSURE IS
TRANSMITTED
TO THE BACK OF
THE EYE BY
OPTIC N.
LEADING TO
PAPILLOEDEMA

16. NERVE OF
ORBIT
ENTERS
ORBIT
THROUGH
ORIGIN COURSE IN ORBIT ACTION
LACRIMAL N. UPPER PART
OF THE
SUPERIOR
ORBITAL
FISSURE
OPHTHALMIC
DIVISION OF
TRIGEMINAL
N.
• PASSES FORWARDS ALONG
THE UPPER BORDER OF THE
LATERAL RECTUS M.
• ITS JOINED BY A BRANCH OF
ZYGOMATICOTEMPORAL N.
WHICH ENTERS LACRIMAL
GLAND (PARASYMPATHETIC
SECRETOMOTOR FIBERS )
• CONVEYS
PARASYMPATHETIC
SECRETO-MOTOR
FIBERS TO LACRIMAL
GL.
• SUPPLIES UPPER
CONJUNCTIVAL
FORNIX
• SUPPLIES SKIN OF
UPPER EYE LID
*
*

17. NERVE OF
ORBIT
ENTERS
ORBIT
THROUGH
ORIGIN COURSE IN ORBIT ACTION
FRONTAL N. UPPER PART
OF SUPERIOR
ORBITAL
FISSURE
OPHTHALMIC
DIVISION OF
TRIGEMINAL N.
• PASSES FORWARDS ON
THE SUPERIOR SURFACE
OF LEVATOR PALPEBRAE
SUPERIORIS.
• DIVIDE IN TO :
1. SUPRAORBITAL N.
2. SUPRATROCHLEAR N.
1. BOTH SUPRAORBITAL
& SUPRATROCHLEAR
N.s WIND AROUND
THE UPPER MARGIN
OF THE ORBITAL
CAVITY TO SUPPLY
THE SKIN OF THE
FOREHEAD
2. SUPRATROCHLEAR N.
ALSO SUPPLIES THE
MUCOUS MEMBRANE
OF THE FRONTAL AIR
SINUS

18. NERVE OF ORBIT
ENTERS
ORBIT
THROUGH
ORIGIN
COURSE IN THE
ORBIT
OCCULOMOTOR N.
(**)
S.O.F MIDBRAIN
• SUPERIOR RAMUS : SUPPLIES /
1. SUPERIOR RECTUS M.
2. LEVATOR PALPEBRAE SUPERIORIS M.
• INFERIOR RAMUS : SUPPLIES /
1. INFERIOR RECTUS M.
2. MEDIAL RECTUS M.
3. INFERIOR OBLIQUE M. ( GIVES OFF A BRANCH TO
CILLIARY GANG. CARRYING PARASYMPATHETIC
SUPPLY TO SPHINCTER PUPILLAE & CILLIARY M.s)
**

19. NERVE OF ORBIT
ENTERS ORBIT
THROUGH
ORIGIN COURSE IN ORBIT
NASOCILIARY N.
(*)
TENDEOUS RING OF
THE SUPERIOR
ORBITAL FISSURE
OPHTHALMIC
DIVISION OF
TRIGEMINAL N
• CROSSES OPTIC N.
• RUNS ALONG UPPER
MARGIN OF MEDIAL
RECTUS M.
BRANCHES OF NASOCILIARY N.
1.
COMMUNICATING
BR. TO CILIARY GANG.
2.
LONG CILIARY
3.
POSTERIOR
ETHMOIDAL
4.
INFRATROCHLEAR 5. ANTERIOR ETHMOIDAL
• A SENSORY N.
• SENSTION FROM
EYE TRANSMITTED
TO CILIARY G. BY
SHORT CILIARY AND
TO NASOCILIARY N.
BY LONG CILIARY N.
• 2-3 IN NUMBER
• CONTAINS SYMP-
ATHETIC FIBERS
FOR DIALTOR
PUPILLAE M. OF
THE IRIS.
• PASSES FORWARDS
TO SCLERA &
CONTINUE
BETWEEN SCLERA
& CHOROID TO
REACH TO THE IRIS
SUPPLIES :
• ETHMOIDAL AIR
SINUS
• SPHENOIDAL AIR
SINUS
• PASSES FORWARDS
BELOW THE PULLEY
OF THE SUPERIOR
OBLIQUE M.
• SUPPLIES THE SKIN
OF THE MEDIAL PART
OF THE UPPER EYE
LID AND ADJACENT
NOSE.
• PASS THROUGH
ANTERIOR ETHMO-
IDAL FORAMEN
• ENTERS ANTERIOR
CRANIAL FOSSA ON
UPPER SURFACE OF
CRIBRIFORM PLATE.
• ENTERS NASAL CAVITY
THROUGH SLIT IN
CRISTA GALI
• APPEARS IN FACE AS
EXT. NASAL BR.
*1
2
3
4
5

20. NASOCILIARY N.
ANT.
POST.
ETHMOIDAL N.
INFRATROCHLEAR N.
LONG CILIARY N.
COMMUNICATING BR.
TO CILIARY GANG

21. NERVE OF
ORBIT
ENTERS ORBIT
THROUGH
ORIGIN ACTION
1. TROCHLEAR N.
UPPER PART OF
S.O.F.
MIDBRAIN SUPPLIES SUPPERIOR OBLIQUE
2. ABDUCENT N.
LOWER PART OF
S.O.F.
PONTOMEDULLARY
JUNCTION
SUPPLIES LATERAL RECTUS
1.
2.

22. CILIARY GANGLION (*)
DEFINITION A PARASYMPATHETIC GANGLION
LOCATION POSTERIOR PART OF THE ORBIT
PREGANGLIONIC FIBERS
RECEIVED FROM OCCULOMOTOR N.
( THROUGH ITS N. TO INF. OBLIQUE
M.)
POSTGANGLIONIC FIBERS
LEAVES THE GANG. TO THE SHORT
CILIARY N.s ENTERS THE EYE BALL
SUPPLYING SPHINCTER PUPILLAE M.
& CILIARIS M.
** A NUMBER OF SYMPATHETIC FIBERS PASSES FROM INTERNAL
CAROTID PLEXUS INTO THE ORBIT THROUGH THE CILIARY
GANG. WITHOUT INTERRUPTION
*

23. OPHTHALMIC ARTERY
ORIGIN
A BRANCH OF INTERNAL CAROTID A.
AFTER EMERGING FROM CAVERNUS SINUS
ENTERS THE ORBIT THROUGH OPTIC CANAL WITH OPTC N.
COURSE IN ORBIT
RUNS FORWARDS, CROSSES THE OPTIC N.
FROM LATERAL TO MEDIAL WALL OF ORBIT
BRANCHES
OF OPHTH
-ALMIC A.
1. CENTRAL A. OF
RETINA
• PIERCES THE MENIGIES OF OPTIC N.
• ENTERS & RUNS IN THE OPTIC N. TO
REACH THE EYE BALL AT THE CENTER OF OPTIC DISC.
• DIVIDES INTO END ARTERIES SUPPLYING THE RETINA
2. MUSCULAR BR.s -
3. CILIARY A.s
• ANTERIOR : SUPPLY EYE BALL AT CORNEOSCLERAL JUNC.
• POSTERIOR : ENTERS OPTIC N.
4. LACRIMAL A. SUPPLIES LACRIMAL GLAND
5.SUPRAORBITAL &
6.SUPRATROCHLEAR A.s
-

24. SUPRAORBITAL BR.
SUPRTROCHLEAR BR.
POSTERIOR CILIARY BR.
OPHTHALMIC A.
LACRIMAL BR.

25. P.V.P
F.V
1
2C.V
NOTE :
NO LYMPHATIC VESSLES OR
NODES IN THE EYES
OPHTHALMIC VEINS
1.
SUPERIOR
OPHTHAL
MIC VEINS
COMMUNICATES
INFRONT WITH
FACIAL VEIN
BOTH VEINS
PASS
BACKWARDS
THROUGH
S.O.F.
BOTH DRAIN
INTO
CAVERNOUS
SINUS
(C.V.)2.
INFERIOR
OPHTHAL
MIC VEIN
COMMUNICATES
WITH
PTERYGOID
VENOUS PLEXUS
(P.V.P) THROUGH
I.O.F.

26. MUSCLES OF THE ORBIT

27. EXTRAOCCULAR MUSCLES OF THE EYE
MUSCLE ORIGIN INSERTION N. SUPPLY
SUPERIOR
RECTUS
TENDENOUS RING ON
THE POSTERIOR WALL OF
THE ORBITAL CAVITY
SUPERIOR SURFACE OF THE EYE BALL JUST
POSTERIOR TO CORNEOSCLERAL JUNCTION
(JPTCSJ)
CN IIIINFERIOR
RECTUS
SAME
INFERIOR SURFACE OF THE EYE BALL
(JPTCSJ)
MEDIAL
RECTUS
SAME
MEDIAL SURFACE OF THE EYE BALL
(JPTCSJ)
LATERAL
RECTUS
SAME
LATERAL SURFACE OF THE EYE BALL
(JPTCSJ)
CN VI
SUPERIOR
OBLIQUE
POSTERIOR WALL OF
ORBITAL CAVITY
PASSES BENEATH THE PULLEY TO BE ATTACHED
TO THE SUPERIOR SURFACE OF THE EYE BALL
BENEATH THE SUPERIOR RECTUS
CN IV
INFERIOR
OBLIQUE
FLOOR OF ORBITAL
CAVITY
LATERAL SURFACE OF THE EYE BALL BENEATH
THE LATERAL RECTUS
CN III

30. EXTRAOCCULAR MUSCLE ACTION
SUPERIOR RECTUS RISES CORNEA UP & MEDIALLY
INFERIOR RECTUS DEPRESSES CORNEA DOWN & MEDIALLY
MEDIAL RECTUS ROTATESCORNEA MEDIALLY
LATERAL RECTUS ROTATES CORNEA LATERALLY
SUPERIOR OBLIQUE ROTATES CORNEA INFEROLATERALLY
INFERIOR OBLIQUE ROTATES CORNEA SUPEROLATERALLY
SR
MR
IR
LR
SO
IO

31. EYELIDS

32. EYE LIDS
• PROTECTS THE EYES FROM INJURY &
EXCESSIVE LIGHT BY THEIR CLOSURE.
• UPPER IS LARGER & MORE MOBILE THAN
LOWER LIDS.
• UPPER & LOWER MEET AT MEDIAL &
LATERAL ANGLES
• PALPEBRAL FISSURE IS AN ELLEPTICAL
OPENING BETWEEN THE LIDS & IS THE
ENTRANCE TO THE CONJUNCTIVAL SAC.

33. MUSLES OF THE EYE LID
MUSCLE ORIGIN INSERTION N. SUPPLY ACTION
LEVATOR
PALPEBRAE
SUPERIORIS
BACK OF ORBITAL
CAVITY
ANTERIOR
SURFACE & UPPER
MARGIN OF THE
SUPERIOR TARSAL
PLATE
• STRIATED :
3RD C.N.
• SMOOTH :
SYMPATHETIC
RSISES UPPER
EYELID
ORBICLARIS
OCULI :
1. PALPEBRAL
PART
2. ORBITAL
PART
MEDIAL PALPEBRAL
LIG.
MEDIAL PALPEBRAL
LIG. & ADJOINING
BONE
LATERAL
PALPEBRAL
RAPHAE
LOOPS & RETURN
TO ORIGIN
FACIAL N.
FACIAL N.
CLOSES EYE LID &
DIALATE LACRIMAL
SAC
PROTECTS EYEBALL

34. STRUCTURES OF THE EYELID
STRUCTURE DEFINITION
1. SKIN COVERS EYELID SUPERFICIALLY,
2. EYE-LASHES
WHICH ARE CURVED HAIR ON FREE EDGE OF EYELID,
ARRANGED IN 2-3 RAWS AT MUCOCUTANE-OUS
JUNCTION.
3. GLAND ZEIS
A SEBACEOUS GL. THAT OPENS DIRECTLY TO THE EYE
LASH FOLLICLES
4. CILIARY GL OF
MOLL
MODIFIED SWEAT GL.s THAT OPEN SEPARATELY
BETWEEN ADJACEN EYE LASHES
5. TARSAL
(MEIBOMIAN)
GLANDS
ARE LONG MODIFIED SEBACEOUS GL. THAT POUR THEIR
OILY SECRETIONS TO THE MARGIN OF THE LID. THEIR
OPENINGS ARE BEHAND EYE LASHES, PRVENT
OVERFLOW OF TEARS & MAKE THE CLOSED EYELIDS
AIRTIGHT

35. STRUCTURES OF THE EYELID
STRUCTURE DEFINITION
6. LACUS LACRIMALIS
SEPARATING THE MEDIAL ANGLE OF
THE EYE LIDS FROM THE EYEBALL
7. CARUNCULA LACRIMALIS
A REDDISH YELLOISH ELEVATION LIES IN
THE CENTER OF THE LACUS
LACRIMALIS
8. PLICA SEMILUNARIS
A SEMILUNAR FOLD LIES AT THE
LATERAL SIDE OF THE CARUNCULE
9. PAPILLA LACRIMALIS
A SMALL ELEVATION ON THE MEDIAL
ENDS OF THE EYELID ( MEDIAL ANGLES)
10. PUNCTUM LACRIMLE
A SMALL HOLE AT THE SUMMIT OF THE
PAPILLA THAT LEADS TO CANALICULUS
LACRIMALIS
6
7
8
9
10

36. STRUCTURES IN EYELIDS
STRUCTURE DEFINITION
11. COJUNCTIVA
• A MUCOUS MEMBRANE THAT LINES EYE LIDS
AND REFLECTED ON THE EYE BALL AS THE
SUP. & INF. FORNICES,IT BECOME CONTINU-
OUS WITH THAT OF THE CORNEA.
• THE UPPER LATERAL PART OF SUP. FORNIX IS
PEIRCED BY THE DUCTS OF THE LACRMAL GL.
• IT FORMS A POTENTIAL SPACE CALLED THE
COJUNCTIVAL SAC, WHICH OPENS AT
PALPEBRAL FISSURE
12. SUBTARSAL
SULCUS
• A GROOVE BENEATH THE EYE LID, RUNS CLOSE
& PARALLEL TO THE LID MARGIN,
• TRAPPS FOREIGN BODIES ENTERRING
CONJUNCTIVAL SAC ( SO ITS IMPORTANT CLIN-
ICALLY ).

37. FRAMEWORK OF EYELID
STRUCTURE DEFINITION
1.ORBITAL
SEPTUM
A FIBROUS SHEET THAT IS ATTACHED TO THE
PERIOSTEUM OF THE ORBITAL MARGINS,
2. TARSAL PLATES
ARE SUP. & INF. THICKENINGS OF THE ORBITAL
SEPTUM AT MARGINS OF THE LIDS, TARSAL GL.s
ARE EMBEDDED IN THE POSTERIOR SURFCAE OF
TARSAL PLATES.
3. LATERAL
PALPEBRAL
LIGAMENT
A BAND ATTACHES LATERAL ENDS OF TARSAL
PLATES TO A BONY TUBERCLE JUST WITHIN
ORBITAL MARGIN
4. MEDIAL
PALPEBRAL
LIGAMENT
A BAND ATTACHES MEDIAL ENDS OF TARSAL
PLATES TO LACRIMAL CREST OF THE MEDIAL
ORBITAL MARGIN
1
2
1
2
3 4

38. 1. ORBICULARIS OCULI (PALPEBRAL PART) :
COVERS THE SUPERFICIAL SURFACE OF
THE TARSAL PLATE & ORBITAL SEPTUM.
2. LEVATOR PALPEBRAE SUPERIORIS :
ITS INSERTION APPONEUROSIS PEIRCES
THE ORBITAL SEPTUM TO REACH THE
ANTERIOR SURFACE OF THE SUPERIOR
TARSAL PLATE & SKIN.
2
1
1

39. LACRIMAL APPARATUS

40. LACRIMAL
APPARATUS
PARTS LOCATION NOTES
1.
LACRIMAL
GLAND
A. PALPEBRAL
( LARGE ) PART
B. ORBITAL
( SMALL ) PART
ABOVE THE EYE BALL IN
ANTERIOR & UP. PART
OF ORBIT POSTERIOR TO
ORBITAL SEPTUM
• BOTH PARTS ARE CONTINUOUS AROUND THE
LATERAL MARGIN OF LEV. PALP. SUP.
APPONEUROSIS
• OPENS TO LATERAL PART OF SUP. FORNIX BY
12 DUCTS.
2. LACRIMAL
DUCTS
1A. LACUS
LACRIMALIS
TEARS ACCUMULATES HERE
2B. PUNCTA
LACRIMALIS
THROUGH IT TEARS ENTER L. CANALICULI
3C. LACRIMAL
CANALICULI
DIRECTS TEARS MEDIALLY TO L. SAC
4D. LACRIMAL
SAC
LACRIMAL GROOVE
BEHIND MEDIAL
PALPEBRAL LIG.
IT’S THE UPPER BLIND END OF THE
NASOLACRIMAL DUCT
5E. NASOLAC-
RIMAL DUCT
1.3 CMs FROM LOWER END OF L. SAC DESCENDS DONWARDS
IN A BONY CANAL TO OPEN IN INFERIOR MEATUS OF NOSE
6F. LACRIMAL
FOLDS
GUARDS THE NLD
OPENING IN INF. MEATUS
PREVENT AIR FROM BEING FORCED UP THE
N.L.D TO L. SAC DURING BLOWING THE NOSE

42. Deep
petrosal N.