superior orbital fissure

Examples of superior orbital fissure in the following topics:

• Oculomotor (III) Nerve

  • It enters the orbit via the superior orbital fissure and controls most of the eye's movements, including constriction of the pupil and maintaining an open eyelid by innervating the levator palpebrae superiors muscle.
  • The oculomotor nucleus originates at the level of the superior colliculus.
  • The muscles it controls are the striated muscle in the levator palpebrae superioris and all extraocular muscles, except for the superior oblique muscle and the lateral rectus muscle.
  • It then divides into two branches that enter the orbit through the superior orbital fissure, between the two heads of the lateral rectus (a muscle on the lateral side of the eyeball in the orbit).
  • Here the nerve is placed below the trochlear nerve and the frontal and lacrimal branches of the ophthalmic nerve, while the nasociliary nerve is placed between its two rami (the superior and inferior branch of oculomotor nerve).

• Abducens (VI) Nerve

  • It then enters the orbit through the superior orbital fissure and innervates the lateral rectus muscle of the eye.

• Cranial Bones

  • The squamous region is the largest and most superior region.
  • The sphenoid bone is situated in the middle of the skull towards the front and forms the rear of the orbit.
  • The lesser wings project laterally and form the floor of the anterior cranial fossa and the superior orbital fissure through which several key optical nerves pass.
  • It is lightweight due to its spongy, air-filled construction and is located at the roof of the nose and between the two orbits.
  • Orbital: This part lies inferiorly and forms the superior border of the orbit.

• Orbits

  • The orbital cavity is formed from seven bones.
  • The frontal bone forms the superior border of the orbital rim and also the superior wall (roof) of the orbital surface.
  • The zygomatic bone forms the lateral (and half of the basal) border of the orbital rim, and also the lateral wall of the orbital surface—this is the thickest region of the orbit as it is most exposed to external trauma.
  • Completing the basal and medial border of the orbital rim is the maxillary bone, which also forms the inferior wall (floor) of the orbital surface.
  • The lacrimal and ethmoid bones contribute to the medial wall of the orbit and also to the medial wall of the orbital canal.

• Lobes, Fissures, and Lobules

  • It lies beneath the oblique fissure.
  • It bears medial, lateral, superior, anterior, and posterior bronchopulmonary segments.
  • It is above the oblique fissure.
  • The lower lobe of the left lung contains superior, anterior, posterior, medial, and lateral bronchopulmonary segments.
  • It contains superior and inferior bronchopulmonary segments.

• Parts of the Cerebellum

  • Based on surface appearance, three lobes can be distinguished in the cerebellum: the flocculonodular lobe, anterior lobe (above the primary fissure), and the posterior lobe (below the primary fissure).
  • Superior view of an "unrolled" cerebellum, placing the vermis in one plane.

• Paranasal Sinuses

  • The maxillary sinuses (also called the maxillary antrechea, the largest of the paranasal sinuses) are located under the orbits in the maxillary bones.
  • The frontal sinuses are superior to the orbits and are in the frontal bone.
  • The ethmoid sinuses are formed from several discrete air cells within the ethmoid bone between the nose and the orbits.

• Medulla Oblongata

  • An open or superior part where the dorsal surface of the medulla is formed by the fourth ventricle.
  • In the lower part of the medulla, some of these fibers cross each other, thus obliterating the anterior median fissure.
  • Other fibers that originate from the anterior median fissure above the decussation of the pyramids and run laterally across the surface of the pons are known as the external arcuate fibers.

• Cerebral Lobes

  • The frontal lobe is an area in the mammalian brain located at the front of each cerebral hemisphere and positioned anterior to (in front of) the parietal lobe and superior and anterior to the temporal lobes.
  • The parietal lobe is a part of the brain positioned above (superior to) the occipital lobe and behind (posterior to) the frontal lobe.
  • The temporal lobe is a region of the cerebral cortex located beneath the lateral fissure on both cerebral hemispheres of the mammalian brain.
  • Adjacent areas in the superior, posterior, and lateral parts of the temporal lobes are involved in high-level auditory processing.
  • The superior temporal gyrus includes an area where auditory signals from the ear first reach the cerebral cortex and are processed by the primary auditory cortex in the left temporal lobe.

• White Matter of the Cerebrum

  • Superior to the brainstem, such tracts form a broad, dense sheet called the internal capsule between the thalamus and basal nuclei, then radiate in a diverging, fanlike array to specific areas of the cortex.
  • The corpus callosum (Latin: "tough body"), also known as the colossal commissure, is a wide, flat bundle of neural fibers beneath the cortex in the eutherian brain at the longitudinal fissure.