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orbit

 [or´bit]
1. the bony cavity containing the eyeball and its associated muscles, vessels, and nerves; the ethmoid, frontal, lacrimal, nasal, palatine, sphenoid, and zygomatic bones and the maxilla contribute to its formation.
2. the path of an electron around the nucleus of an atom. adj., adj or´bital.

or·bit

(ōr'bit), [TA]
The bony cavity containing the eyeball and its adnexa; it is formed of parts of seven bones: the frontal, maxillary, sphenoid, lacrimal, zygomatic, ethmoid, and palatine.
Synonym(s): orbita [TA], eye socket

orbit

/or·bit/ (or´bit) the bony cavity containing the eyeball and its associated muscles, vessels, and nerves.or´bital

orbit

(ôr′bĭt)

orbit

[ôr′bit]
Etymology: L, orbita, wheel track
one of a pair of bony, conical cavities in the skull that accommodate the eyeballs and associated structures, such as the eye muscles, nerves, and blood vessels. The medial walls of the orbits are approximately parallel with each other and with the middle line, but the lateral walls diverge widely. The roof of each orbit is formed by the orbital plate of the frontal bone and the small wing of the sphenoid bones. The openings that communicate with each orbit are the optic foramen, the superior and the inferior orbital fissures, the supraorbital foramen, the infraorbital canal, the anterior and posterior ethmoidal foramina, the zygomatic foramen, and the canal for the nasolacrimal duct. orbital, adj.
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Bones of the orbit

ORBIT

Cardiology A clinical trial Oral Glycoprotein IIb/IIIa receptor Blockade to Inhibit Thrombosis

or·bit

(ōr'bit) [TA]
The bony cavity containing the eyeball and its adnexa; it is formed of parts of the frontal, maxillary, sphenoid, lacrimal, zygomatic, ethmoid, and palatine bones.
Synonym(s): orbita [TA] , orbital cavity.

orbit

The bony cavern in the skull that contains the eyeball and OPTIC NERVE, the muscles that move the eye, the LACRIMAL GLAND, a quantity of fat and various arteries, veins and nerves.

orbit

the body cavity or socket in the vertebrate skull containing the eyeball.

Orbit

The cavity in the skull containing the eye-ball; formed from seven bones: frontal, maxillary, sphenoid, lacrimal, zygomatic, ethmoid, and palatine.

orbit,

n hollow space where the eyeball and its muscles, nerves, and blood vessels are located.
Enlarge picture
Orbit.

orbit 

A rigid bony cavity in the skull which contains an eyeball, orbital fat, the extraocular muscles, the optic nerve, nerves and blood vessels, lacrimal system and fibrous tissue of various kinds. This packing serves to keep the eyeball reasonably well fixed in place as it rotates. The orbital cavity has the approximate form of a pyramid. The walls of the orbital cavity are formed by seven bones. The medial wall of the orbit consists of: (1) the frontal process of the maxilla (maxillary); (2) the lacrimal bone; (3) the lamina papyracea of the ethmoid; and (4) a small part of the body of the sphenoid. The floor of the orbit consists of: (1) the orbital plate of the maxilla; (2) the orbital surface of the zygomatic (malar) bone and (3) the orbital process of the palatine bone. The lateral wall of the orbit consists of (1) the orbital surface of the greater wing of the sphenoid, and (2) the orbital surface of the zygomatic. The roof of the orbit is made up mainly by the frontal bone and behind this by the lesser wing of the sphenoid. The orbit is lined with a membrane of tissue called the periorbita (or orbital periosteum) which extends to the orbital margin (anterior rim of the orbit) where it becomes continuous with the periosteum covering the facial bones. The periorbita is loosely attached to the bones except at sutures, foramina and the orbital margin where it is firmly attached. The bones are much thicker at the margin (rim) than they are along the walls of the orbital cavity. There are many apertures and gaps in the orbit through which blood vessels and nerves pass (see Table O4). See orbital axis; optic canal; inferior orbital fissure; superior orbital fissure; orbital fracture; cavernous haemangioma; lamina papyracea.
Table O3 Bones forming the walls of the orbit
roofmedial wall
1. frontal1. maxilla
2. lesser wing of sphenoid2. lacrimal
3. ethmoid
4. sphenoid
floorlateral wall
1. maxilla1. greater wing of sphenoid
2. zygomatic
3. palatine2. zygomatic

Table O4 Orbital apertures
aperturelocationcontents
optic canalat the apex (in lesser sphenoid)optic nerve
ophthalmic artery
sympathetic nerve fibres
superior orbital fissureat the apex (gap between greater and lesser sphenoid)III, IV, V, VI nerves
sympathetic nerve fibres
ophthalmic vein
recurrent lacrimal artery
inferior orbital fissurebetween lateral wall and posterior part of the floorinfraorbital nerve
zygomatic nerve
branch of inferior ophthalmic vein
nerve fibres from the
pterygopalatine (sphenopalatine)
ganglion to orbital periosteum
ethmoidal foramina (anterior and post.)medial wall (frontal/ethmoidal suture)ethmoidal vessels
ethmoidal nerve/external nasal nerve
zygomatic foramenlateral wallzygomatic nerve and vessels
nasolacrimal canalmedial wall (maxilla/lacrimal)nasolacrimal duct

or·bit

(ōr'bit) [TA]
Bony cavity containing eyeball and its adnexa.

orbit,

n 1. in chemistry, refers to the movement of an electron around an atom's nucleus.
2. the bony socket that contains the eyeball and all its supporting structures.

orbit

1. the bony cavity containing the eyeball and its associated muscles, vessels and nerves; the ethmoid, frontal, lacrimal, nasal, palatine, sphenoid and zygomatic bones and the maxilla contribute to its formation.
2. the path of an electron around the nucleus of an atom.
References in classic literature ?
The unusual size of the orbits in which they were set was enough of itself to attract attention; it gave a grandeur to his head, which the head, broad and firm as it was, did not possess.
His eyes which were blue like hers, only faded, without depth, seemed to start out of their orbits.
For example, in thinking of the Solar System, you are likely to have vague images of pictures you have seen of the earth surrounded by clouds, Saturn and his rings, the sun during an eclipse, and so on; but none of these form part of your belief that the planets revolve round the sun in elliptical orbits.
Rosenthall's revolvers were describing widening orbits.
In the dark patches of the orbits the eyeballs glimmered piercingly.
He had a superior eye-glass dangling round his neck, but unfortunately had such flat orbits to his eyes and such limp little eyelids that it wouldn't stick in when he put it up, but kept tumbling out against his waistcoat buttons with a click that discomposed him very much.
Then there was a wild yelp of agony and the poodle went sailing up the aisle; the yelps continued, and so did the dog; he crossed the house in front of the altar; he flew down the other aisle; he crossed before the doors; he clamored up the home-stretch; his anguish grew with his progress, till presently he was but a woolly comet moving in its orbit with the gleam and the speed of light.
To this catalogue of circumstances that tend to the amelioration of popular systems of civil government, I shall venture, however novel it may appear to some, to add one more, on a principle which has been made the foundation of an objection to the new Constitution; I mean the ENLARGEMENT of the ORBIT within which such systems are to revolve, either in respect to the dimensions of a single State or to the consolidation of several smaller States into one great Confederacy.
I am of another world," I answered, "the great planet Earth, which revolves about our common sun and next within the orbit of your Barsoom, which we know as Mars.
But Phileas Fogg, who was not travelling, but only describing a circumference, took no pains to inquire into these subjects; he was a solid body, traversing an orbit around the terrestrial globe, according to the laws of rational mechanics.
In other words the diameter of this orbit is about 480,000 miles.
Her mighty orbit vaults like the fresh rainbow into the deep, but no archangel's wing was yet strong enough to follow it and report of the return of the curve.