1 Eyelids. Lacrimal Apparatus. Orbital Region. 3 The Orbit. The Eye

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Milton Booker
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2 1 Eyelids Orbital Region 2 Lacrimal Apparatus 3 The Orbit 4 The Eye 2

3 Eyelids The eyelids protect the eye from injury and excessive light by their closure. The upper eyelid is larger and more mobile than the lower, and they meet each other at the medial and lateral angles. The palpebral fissure is the elliptical opening between the eyelids and is the entrance into the conjunctival sac. 3

4 Eyelids Glands The ciliary glands (glands of Moll) are modified sweat glands that open separately between adjacent lashes. The sebaceous glands (glands of Zeis) open directly into the eyelash follicles. The tarsal glands are long, modified sebaceous glands that pour their oily secretion onto the margin of the lid; their openings lie behind the eyelashes. 4

5 Eyelids - Medial Angle 5

6 The Conjunctiva + Muscles The conjunctiva is a thin mucous membrane that lines the eyelids and is reflected at the superior and inferior fornices onto the anterior surface of the eyeball. Subtarsal sulcus foreign particles 6

7 The Orbital Septum The framework of the eyelids is formed by a fibrous sheet. Attached to the periosteum at the orbital margins. Thickened at the margins of the lids to form the superior and inferior tarsal plates. Lateral palpebral ligament. The medial palpebral ligament. 7

8 Lacrimal Apparatus Lacrimal Gland Lacrimal Ducts

9 Lacrimal Gland Large orbital Small palpebral part The gland opens into the lateral part of the superior fornix of the conjunctiva by 12 ducts. 9

10 Lacrimal Gland - Nerve Supply 10

11 Lacrimal Ducts Lacus lacrimalis Puncta lacrimalis Canaliculi lacrimales Lacrimal sac Nasolacrimal duct. 11

12 The Orbit The orbit is a pyramidal cavity with its base in front and its apex behind. 12

13 The orbital margin 13

14 Roof Orbital plate of the frontal bone Orbital Walls Lateral wall Floor Zygomatic bone Greater wing of the sphenoid Orbital plate of the maxilla Frontal process of the maxilla Medial wall Lacrimal bone Orbital plate of the ethmoid Body of the sphenoid

vessels nasolacrimal duct maxillary nerve and its zygomatic branch inferior ophthalmic vein sympathetic nerves.

15 Openings Into the Orbital Cavity Orbital opening Supraorbital notch Infraorbital groove and canal Nasolacrimal canal Inferior orbital fissure Superior orbital fissure one-sixth of the eye supraorbital nerve and blood vessels infraorbital nerve and blood vessels nasolacrimal duct maxillary nerve and its zygomatic branch inferior ophthalmic vein sympathetic nerves. (Lacrimal, frontal, trochlear) nerves, superior ophthalmic vein (Abducent, oculomotor, nasociliary) nerves Optic canal Optic nerve Ophthalmic artery

16 Orbital Fascia The orbital fascia is the periosteum of the bones that form the walls of the orbit. It is loosely attached to the bones and is continuous through the foramina and fissures with the periosteum covering the outer surfaces of the bones. 16

Nerves of the Orbit II Optic Nerve Cerebrospinal fluid III Oculomotor Nerve Superior ramus Superior rectus m Levator palpebrae superioris m Inferior rectus m IV Trochlear Nerve inferior ramus Medial

17 Nerves of the Orbit II Optic Nerve Cerebrospinal fluid III Oculomotor Nerve Superior ramus Superior rectus m Levator palpebrae superioris m Inferior rectus m IV Trochlear Nerve inferior ramus Medial rectus m Inferior oblique m Lacrimal Nerve Frontal Nerve Supratrochlear n Supraorbital n V Trigeminal Nerve Ophthalmic division Maxillary division Communicating branch Long ciliary nn VI Abducent Nerve Mandibular division Nasociliary Nerve Infratrochlear n Posterior ethmoidal n Anterior ethmoidal n

18 Oculomotor nerve [III] 18

19 Trochlear nerve [IV] 19

20 Ophthalmic nerve [V1] 20

21 Ciliary Ganglion 21

22 Central artery of the retina Muscular branches Internal Carotid Artery Ophthalmic Artery Ciliary arteries Lacrimal artery supratrochlear and supraorbital arteries

23 Ophthalmic Artery 23

24 Veins

25 Lymph Vessels No lymph vessels or nodes are present in the orbital cavity. 25

26 Extrinsic Muscles Producing Movement of the Eye 26

27 Action of individual muscles (anatomical action)

28 Movement of eye when testing specific muscle (clinical testing).

29 Movement of eye when testing specific muscle (clinical testing). 29

30 Fascial Sheath of the Eyeball Surrounds the eyeball from the optic nerve to the corneoscleral junction. Separates the eyeball from the orbital fat and provides it with a socket for free movement. It is perforated by the tendons of the orbital muscles and is reflected onto each of them as a tubular sheath. 30

Fascial Sheath of the Eyeball The sheaths for the tendons of the medial and lateral recti are attached to the medial and lateral walls of the orbit by triangular ligaments called the medial and

31 Fascial Sheath of the Eyeball The sheaths for the tendons of the medial and lateral recti are attached to the medial and lateral walls of the orbit by triangular ligaments called the medial and lateral check ligaments. The lower part of the fascial sheath, which passes beneath the eyeball and connects the check ligaments, is thickened and serves to suspend the eyeball; it is called the suspensory ligament of the eye. 31

32 Fibrous coat Sclera Cornea The Choroid Outer pigmented layer Inner vascular layer Eyeball Vascular pigmented coat Ciliary ring The Ciliary Body Ciliary processes Iris Ciliary muscle Nervous coat Outer pigmented layer Inner nervous layer

33 33

34 Ciliary body 34

35 Aqueous Humor Contents of the Eyeball Vitreous Body The Lens

36 Lens and zonula ciliaris 36

Eye Trauma The eyeball is protected anteriorly only from large objects, such as tennis balls, which tend to strike the orbital margin but not the globe.

37 Eye Trauma The eyeball is protected anteriorly only from large objects, such as tennis balls, which tend to strike the orbital margin but not the globe. The bony orbit provides no protection from small objects, such as golf balls, which can cause severe damage to the eye. The orbital margins shows that it is least protected from the lateral side. 37

38 38

The sebaceous glands (glands of Zeis) open directly into the eyelash follicles, ciliary glands (glands of Moll) are modified sweat glands that open

The sebaceous glands (glands of Zeis) open directly into the eyelash follicles, ciliary glands (glands of Moll) are modified sweat glands that open The Orbital Region The orbits are a pair of bony cavities that contain the eyeballs; their associated muscles, nerves, vessels, and fat; and most of the lacrimal apparatus upper eyelid is larger and more