Arachnoid granulations are small protrusions of the arachnoid mater into the outer membrane of the dura mater. They protrude into the dural venous sinuses of the brain, and allow cerebrospinal fluid (CSF) to exit the subarachnoid space and enter the blood stream.
Dura mater is a thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord. It is the outermost of the three layers of membrane called the meninges that protect the central nervous system. The other two meningeal layers are the arachnoid mater and the pia mater. The dura surrounds the brain and the spinal cord. It envelops the arachnoid mater, which is responsible for keeping in the cerebrospinal fluid. It is derived primarily from the neural crest cell population, with postnatal contributions of the paraxial mesoderm.
The great cerebral vein is one of the large blood vessels in the skull draining the cerebrum of the brain. It is also known as the "vein of Galen", named for its discoverer, the Greek physician Galen. However, it is not the only vein with this eponym.
Cerebral circulation is the movement of blood through a network of cerebral arteries and veins supplying the brain. The rate of cerebral blood flow in an adult human is typically 750 milliliters per minute, or about 15% of cardiac output. Arteries deliver oxygenated blood, glucose and other nutrients to the brain. Veins carry "used or spent" blood back to the heart, to remove carbon dioxide, lactic acid, and other metabolic products. Because the brain would quickly suffer damage from any stoppage in blood supply, the cerebral circulatory system has safeguards including autoregulation of the blood vessels. The failure of these safeguards may result in a stroke. The volume of blood in circulation is called the cerebral blood flow. Sudden intense accelerations change the gravitational forces perceived by bodies and can severely impair cerebral circulation and normal functions to the point of becoming serious life-threatening conditions.
In anatomy, the epidural space is the potential space between the dura mater and vertebrae (spine)
The falx cerebri, also known as the cerebral falx, is a large, crescent-shaped fold of meningeal layer of dura mater that descends vertically in the longitudinal fissure between the cerebral hemispheres of the human brain. The falx cerebri attaches anteriorly at the crista galli in proximity to the cribriform plate and to the frontal and ethmoid sinuses. Posteriorly, it is connected with the upper surface of the cerebellar tentorium. Its superior margin is attached at midline to the internal surface of skull, as far back as the internal occipital protuberance. The superior sagittal sinus is contained in the superior margin of the falx cerebri and overlies the longitudinal fissure of the brain. The inferior sagittal sinus is contained in the inferior margin of the falx cerebri and arches over the corpus callosum, deep in the longitudinal fissure. The falx cerebri is named for its sickle-like form.
The cerebellar tentorium or tentorium cerebelli is an extension of the dura mater that separates the cerebellum from the inferior portion of the occipital lobes.
The cavernous sinus within the human head is one of the dural venous sinuses creating a cavity called the lateral sellar compartment bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica.
The dural venous sinuses are venous channels found between the endosteal and meningeal layers of dura mater in the brain. They receive blood from the cerebral veins, receive cerebrospinal fluid (CSF) from the subarachnoid space via arachnoid granulations, and mainly empty into the internal jugular vein.
The confluence of sinuses, torcular Herophili, or torcula is the connecting point of the superior sagittal sinus, straight sinus, and occipital sinus. It is below the internal occipital protuberance of the skull. It drains venous blood from the brain into the transverse sinuses. It may be affected by arteriovenous fistulas, a thrombus, major trauma, or surgical damage, and may be imaged with many radiology techniques.
The straight sinus, also known as tentorial sinus or the sinus rectus, is an area within the skull beneath the brain. It receives blood from the inferior sagittal sinus and the great cerebral vein, and drains into the confluence of sinuses.
The superior sagittal sinus, within the human head, is an unpaired area along the attached margin of the falx cerebri. It allows blood to drain from the lateral aspects of anterior cerebral hemispheres to the confluence of sinuses. Cerebrospinal fluid drains through arachnoid granulations into the superior sagittal sinus and is returned to venous circulation.
The inferior petrosal sinuses are two small sinuses situated on the inferior border of the petrous part of the temporal bone, one on each side. Each inferior petrosal sinus drains the cavernous sinus into the internal jugular vein.
The sigmoid sinuses, also known as the pars sigmoid, are venous sinuses within the skull that receive blood from posterior dural venous sinus veins.
The transverse sinuses, within the human head, are two areas beneath the brain which allow blood to drain from the back of the head. They run laterally in a groove along the interior surface of the occipital bone. They drain from the confluence of sinuses to the sigmoid sinuses, which ultimately connect to the internal jugular vein. See diagram : labeled under the brain as "SIN. TRANS.".
The frontal crest of the frontal bone ends below in a small notch which is converted into a foramen, the foramen cecum, by articulation with the ethmoid.
The occipital vein is a vein of the scalp. It originates from a plexus around the external occipital protuberance and superior nuchal line to the back part of the vertex of the skull. It usually drains into the internal jugular vein, but may also drain into the posterior auricular vein. It drains part of the scalp.
The cerebellar veins are veins which drain the cerebellum. They consist of the superior cerebellar veins and the inferior cerebellar veins. The superior cerebellar veins drain to the straight sinus and the internal cerebral veins. The inferior cerebellar veins drain to the transverse sinus, the superior petrosal sinus, and the occipital sinus.
The sphenoparietal sinus is one of the paired dural venous sinuses which drains blood from the brain. It drains the superficial middle cerebral vein, frontal ramus of middle meningeal vein and anterior temporal diploic vein to the cavernous sinus. The sphenoparietal sinus travels along the sphenoidal ridge of the sphenoid bone between the anterior cranial fossa and middle cranial fossa.
This article describes anatomical terminology that is used to describe the central and peripheral nervous systems - including the brain, brainstem, spinal cord, and nerves.
