What structures pass through the optic canals of the sphenoid bone?
The blood vessels pass through the foramina present in the wings of the sphenoid bone. The ophthalmic artery passes through the optic canal to enter the orbit. The ophthalmic veins pass out of the orbit through the superior orbital fissure.
Which bones form the optic canal?
The optic foramen is the opening to the optic canal. The canal is located in the sphenoid bone; it is bounded medially by the body of the sphenoid and laterally by the lesser wing of the sphenoid.
What part of the sphenoid bone houses the optic nerve?
The lesser wing arises from the anterior aspect of the sphenoid body in a superolateral direction. It separates the anterior cranial fossa from the middle cranial fossa. It also forms the lateral border of the optic canal – through which the optic nerve and ophthalmic artery travel to reach the eye.
What runs through optic canal?
The optic canal is a cylindrical canal running obliquely through the lesser wing of sphenoid bone near the base where it joins the body of sphenoid. It transmits the optic nerve and ophthalmic artery (and its associated sympathetic fibers). The optic canal opens into the skull base at the optic foramen.
What does the optic nerve pass through?
When the nerve emerges from the back of the eye, it passes through the remainder of the posterior orbit (eye socket) and through the bony optic canal to emerge intracranially on the underside of the front of the brain.
What three structures does the sphenoid bone have?
The sphenoid bone consists of four main parts: the body, the lesser and greater wings and the pterygoid processes. These parts participate in the formation of important bony cavities (e.g. sella turcica, orbit), as well as canals and foramina of the cranium that serve as passageways for neurovascular structures.
Is the optic canal in the anterior cranial fossa?
The lesser wings of the sphenoid bone form the crescentic posterior borders of the anterior fossa. The optic canal is formed by the two roots of the lesser wing of the sphenoid and runs forward and laterally in the superolateral wall of the sphenoid sinus to the orbital apex.
What is unique about the sphenoid bone?
What’s particularly unique about the sphenoid bone, is that on its cranial surface, the body has a deeply concave surface called the sella turcica. It is bordered by the anterior, middle and posterior clinoid processes, which are points of attachment for the dura mater of the brain.
What sits in the sella turcica?
The pituitary sits protected inside a saddle-like bony compartment in the base of the skull. This compartment is called the sella. When the pituitary gland shrinks or becomes flattened, it cannot be seen on an MRI scan.
Where does the optic canal exit?
Anatomy of the eye and orbit The optic nerves leave the cranial end of the optic canal and pass medially, backwards and slightly upwards within the subarachnoid space of the middle cranial fossa. They end by forming the optic chiasma in the floor of the third ventricle.
What part of the brain is the optic nerve connected to?
The optic nerve connects the retina to the visual cortex in the back of the brain.
Where does the optic nerve enter the skull?
Accompanied by the ophthalmic artery, the optic nerve enters the bony skull through the optic foramen and travels within the optic canal to reach the middle cranial fossa. Located in the middle cranial fossa is the optic chiasm.
Where is optic foramen?
The optic foramen, the opening through which the optic nerve runs back into the brain and the large ophthalmic artery enters the orbit, is at the nasal side of the apex; the superior orbital fissure is a larger hole through which pass large veins and nerves.…
What bones are in the anterior cranial fossa?
The anterior cranial fossa is an important anatomical landmark in clinical orthodontics consisting of the frontal, ethmoid, and sphenoid bones. The relationships between these bones remain poorly understood.
Why is sphenoid bone called the Keystone?
A prominent, irregular, wedge-shaped bone at the base of the skull. The sphenoid bone has been called the “keystone” of the cranial floor since it is in contact with all of the other cranial bones.
Why is the sella turcica important?
During embryological development, the sella turcica area is the key point for the migration of the neural crest cells to the frontonasal and maxillary developmental fields. The neural crest cells are involved in the formation and development of sella turcica and teeth.
What is another name for sella turcica?
human skull portion of this seat, or sella turcica (“Turk’s saddle”), is actually wall-like and is called the dorsum sellae. The pituitary gland is thus situated in almost the centre of the cranial cavity.
How long is optic canal?
Results: In average: (1) The transverse diameter of the optic canal was (3.57 +/- 0.61) mm, the longitudinal diameter was (4.82 +/- 0.38) mm, the length of the inner wall was (12.62 +/- 2.59) mm, the length of the outer wall was (10.18 +/- 2.19) mm, and the length of the optic canal was (11.46 +/- 2.35) mm.