The oculomotor nerve, also known as the third cranial nerve, cranial nerve III, or simply CN III, is a cranial nerve that enters the orbit through the superior orbital fissure and innervates extraocular muscles that enable most movements of the eye and that raise the eyelid. The nerve also contains fibers that innervate the intrinsic eye muscles that enable pupillary constriction and accommodation. The oculomotor nerve is derived from the basal plate of the embryonic midbrain. Cranial nerves IV and VI also participate in control of eye movement.
The cerebral peduncles are the two stalks that attach the cerebrum to the brainstem. They are structures at the front of the midbrain which arise from the ventral pons and contain the large ascending (sensory) and descending (motor) tracts that run to and from the cerebrum from the pons. Mainly, the three common areas that give rise to the cerebral peduncles are the cerebral cortex, the spinal cord and the cerebellum. The region includes the tegmentum, crus cerebri and pretectum. By this definition, the cerebral peduncles are also known as the basis pedunculi, while the large ventral bundle of efferent fibers is referred to as the cerebral crus or the pes pedunculi.
In neuroanatomy, the optic tract is a part of the visual system in the brain. It is a continuation of the optic nerve that relays information from the optic chiasm to the ipsilateral lateral geniculate nucleus (LGN), pretectal nuclei, and superior colliculus.
The salpingopharyngeus muscle is a muscle of the pharynx. It arises from the lower part of the cartilage of the Eustachian tube, and inserts into the palatopharyngeus muscle by blending with its posterior fasciculus. It is innervated by vagus nerve via the pharyngeal plexus. It raises the pharynx and larynx during deglutition (swallowing) and laterally draws the pharyngeal walls up. It opens the pharyngeal orifice of the Eustachian tube during swallowing to allow for the equalization of pressure between it and the pharynx.
The nasociliary nerve is a branch of the ophthalmic nerve (CN V1) (which is in turn a branch of the trigeminal nerve (CN V)). It is intermediate in size between the other two branches of the ophthalmic nerve, the frontal nerve and lacrimal nerve.
The lacrimal nerve is the smallest of the three main branches of the ophthalmic nerve (CN V1) (itself a branch of the trigeminal nerve (CN V)).
The anterior ethmoidal artery is a branch of the ophthalmic artery in the orbit. It exits the orbit through the anterior ethmoidal foramen alongside the anterior ethmoidal nerve. It contributes blood supply to the ethmoid sinuses, frontal sinuses, the dura mater, lateral nasal wall, and nasal septum. It issues a meningeal branch, and nasal branches.
The deep temporal nerves are typically two nerves (one anterior and one posterior) which arise from the mandibular nerve (CN V3) and provide motor innervation to the temporalis muscle.
The zygomaticotemporal nerve (zygomaticotemporal branch, temporal branch) is a cutaneous (sensory) nerve of the head. It is a branch of the zygomatic nerve (itself a branch of the maxillary nerve (CN V2)). It arises in the orbit and exits the orbit through the zygomaticotemporal foramen in the zygomatic bone to enter the temporal fossa. It is distributed to the skin of the side of the forehead. It also contains a parasympathetic secretomotor component for the lacrimal gland which it confers to the lacrimal nerve (which then delivers it to the gland).
The tuber cinereum is the portion of hypothalamus forming the floor of the third ventricle situated between the optic chiasm, and the mammillary bodies. The tuberal region is one of the three regions of the hypothalamus, the other two being the chiasmatic region and the mamillary region.
The sphenopalatine foramen is a foramen of the skull that connects the nasal cavity and the pterygopalatine fossa. It gives passage to the sphenopalatine artery, nasopalatine nerve, and the superior nasal nerve.
The middle cranial fossa is formed by the sphenoid bones, and the temporal bones. It lodges the temporal lobes, and the pituitary gland. It is deeper than the anterior cranial fossa, is narrow medially and widens laterally to the sides of the skull. It is separated from the posterior cranial fossa by the clivus and the petrous crest.
The posterior meningeal artery is one of the meningeal branches of the ascending pharyngeal artery. It passes through the jugular foramen to enter the posterior cranial fossa. It is the largest vessel supplying the dura of the posterior cranial fossa.
The posteromedial central arteries or paramedian arteries (also are branches of the posterior cerebral artery, and posterior communicating artery. They entering the substance of the brain through the posterior perforated substance. They supply a large portion of the diencephalon as well as some subcortical telencephalic structures.
The prepontine cistern, or pontine cistern is one of the subarachnoid cisterns situated ventral to the pons. It contains the basilar artery. Each lateral aperture opens into the pontine cistern just posterior to the cranial nerve VIII.
The interpeduncular cistern is the subarachnoid cistern situated between the dorsum sellae (anteriorly) and the two cerebral peduncles at the front of the midbrain. Its roof is represented by the floor of the third ventricle. Its floor is formed by the arachnoid membrane extending between the temporal lobes of either side. Anteriorly, it extends to the optic chiasm.
The chiasmatic cistern or suprasellar cistern is a small subarachnoid cistern related to the optic chiasm.
The cistern of lateral cerebral fossa is an elongated subarachnoid cistern formed by arachnoid mater bridging the lateral sulcus between the frontal, temporal, and parietal opercula. The cistern contains the middle cerebral artery (MCA) and its branches, and the two middle cerebral veins (MCVs).
The ambient cistern is a bilaterally paired subarachnoid cistern situated at either lateral aspect of the mesencephalon (midbrain). Each ambient cistern has a supratentorial compartment and an infratentorial compartment. Each is continuous anteriorly with the interpeduncular cistern, and posteriorly with the quadrigeminal cistern.
Posterolateral central arteries are arteries that arise from the posterior cerebral artery distal to its first - pre-communicating (P1) -segment.
