Transcript Infratemporal fossa via inferior orbital fissure (4)

ORBITAL CAVITY
A pyramidal space with a base, apex and four walls.
Boundaries and Walls:
Roof
Orbital plate of frontal b.
Lesser wing of sphenoid b.
•
1.
2.
3.
Floor
Orbital surface of maxilla
Zygomatic bone
Orbital process of palatine b.
•
1.
2.
3.
Medial wall
Lacrimal bone
Orbital plate of ethmoid b.
Body of sphenoid b.
•
1.
2.
Lateral wall
Zygomatic b.
Greater wing of sphenoid b.
Frontal
bone
Greater wing
of sphenoid
Ethmoid
bone
Maxillary
bone
Lacrimal bone
•
1.
2.
Some Features of The Orbit
•Lacrimal fossa (1)
•Lacrimal groove and crests (2)
•Trochlear fovea (3)
•Ant. and post. ethmoidal canals (4)
•Zygomatico-facial and Z-temporal canals
•Optic canal (5)
•Supraorbital foramen (6)
•Infraorbital groove, canal and foramen (7)
•Superior orbital fissure (8)
•Inferior orbital fissure (9)
(lodges the orbital part of the lacrimal gland)
(lodges the lacrimal sac)
(attachment of the trochlea)
(ant. and post. ethmoidal nerves and vessels)
(zygomaticofacial and z-temporal n. and v.)
(optic nerve, ophthalmic a. & meningeal sheath)
(supraorbital n. and v.)
(infraorbital n. and v.)
6
1
3
4
8
9
5
2
7
7
Communications of the Orbit
The orbital cavity communicates with the:
•Anterior cranial fossa via ant. and post. ethmoidal canals (1)
•Middle cranial fossa
via optic canal and the superior orbital fissure (2, 3)
•Infratemporal fossa
via inferior orbital fissure (4)
•Nasal cavity
via nasolacrimal canal (5)
1
2
3
5
4
Contents of the Orbital Cavity
•Orbital fat
•Eyeball
•Muscles
•Vessels
•Nerves
•Ciliary ganglion
•Lacrimal gland
Muscles of the Orbit
Levator palpebrae suprioris
Extrinsic muscles of the eye
4 Recti muscles
•Superior rectus
•Inferior rectus
•Medial rectus
•Lateral rectus
2 Oblique muscle
•Superior oblique
•Inferior oblique
Intrinsic muscles of the eye
•Dilator pupillae
•Constrictor pupillae
•Ciliary muscle
Levator palpebrae superioris m.
O:
I:
A:
N:
roof of the orbit in front of the optic canal
superficial lamella:
front of superior tarsus & skin of upper eyelid
deep lamella:
upper border of superior tarsus & superior fornix of conjunctiva
elevation of upper eyelid and sup fornix of conjunctiva
sup division of oculomotor n.
Levator
palp sup
Lev
Palp
Sup
Insertion of
lev palp sup
Superior
tarsus