Cerebellar tentorium | |
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Details | |
Part of | Meninges |
Identifiers | |
Latin | tentorium cerebelli |
NeuroNames | 1240 |
TA98 | A14.1.01.104 |
TA2 | 5375 |
FMA | 83966 |
Anatomical terms of neuroanatomy |
The cerebellar tentorium or tentorium cerebelli (Latin for "tent of the cerebellum") is one of four dural folds that separate the cranial cavity into four (incomplete) compartments. The cerebellar tentorium separates the cerebellum from the cerebrum forming a supratentorial and an infratentorial region; the cerebrum is supratentorial and the cerebellum infratentorial. [1]
The free border of the tentorium gives passage to the midbrain (the upper-most part of the brainstem).
The free border of the tentorium is U-shaped; it forms an aperture - the tentorial notch (tentorial incisure) - which gives passage to the midbrain. The free border of each side extends anteriorly beyond the medial end of the superior petrosal sinus (i.e. the apex of the petrous part of the temporal bone[ citation needed ]) to overlap the attached margin, thenceforth forming a ridge of dura matter upon the roof of the cavernous sinus, terminating anteriorly by attaching at the anterior clinoid process. [2] : 440
The tentorium slopes superior-ward so that the free border is situated at a more superior level than its bony attachment, thus conforming to the shape of the surfaces of the cerebrum and cerebellum with which it is in contact. [2] : 440
The attached margin of the tentorium cerebelli is attached at the edges of the transverse sinuses and superior petrosal sinus (here, the two layers of the tentorium diverge to embrace the sinuses); [2] : 440 it thus attaches onto the occipital bone posteriorly, and (the superior angle of) the petrous part of the temporal bone anteriorly.[ citation needed ]
Anteriorly, its attachment extends to the posterior clinoid processes; posteriorly, it extends to the internal occipital protuberance. [2] : 440
It is attached, behind, by its convex border, to the transverse ridges upon the inner surface of the occipital bone, and there encloses the transverse sinuses; in front, to the superior angle of the petrous part of the temporal bone on either side, enclosing the superior petrosal sinuses.[ citation needed ]
The posterior end of the falx cerebri attaches onto the midline of the upper surface of the tentorium; the straight sinus runs along this line of junction.[ citation needed ]
Brain tumors are often characterized as supratentorial (above the tentorium) and infratentorial (below the tentorium). The location of the tumor can help in determining the type of tumor, as different tumors occur with different frequencies at each location. Additionally, most childhood primary brain tumors are infratentorial, while most adult primary brain tumors are supratentorial. The location of the tumor may have prognostic significance as well.
Since the tentorium is a hard structure, if there is an expansion of the volume of the brain or its surrounding matter above the tentorium, such as because of a tumour or bleeding, the brain can get pushed down partly through the tentorium. This is called herniation and will often cause an enlarged pupil on the affected side, due to pressure on the oculomotor nerve. Tentorial herniation is a serious symptom, especially since the brainstem is likely to be compressed as well if the intracranial pressure rises further. A common type of herniation is uncal herniation.
Calcifications within the cerebellar tentorium are not very common in elderly people; they are not accompanied by any disease and have no known cause. [3]
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The internal carotid artery is an artery in the neck which supplies the anterior and middle cerebral circulation.
In neuroanatomy, 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. 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.
In anatomy, the epidural space is the potential space between the dura mater and vertebrae (spine).
In anatomy, the supratentorial region of the brain is the area located above the tentorium cerebelli. The area of the brain below the tentorium cerebelli is the infratentorial region. The supratentorial region contains the cerebrum, while the infratentorial region contains the cerebellum.
The posterior cranial fossa is the part of the cranial cavity located between the foramen magnum, and tentorium cerebelli. It is formed by the sphenoid bones, temporal bones, and occipital bone. It lodges the cerebellum, and parts of the brainstem.
The falx cerebri is a large, crescent-shaped fold of dura mater that descends vertically into the longitudinal fissure to separate the cerebral hemispheres. It supports the dural sinuses that provide venous and CSF drainage from the brain. It is attached to the crista galli anteriorly, and blends with the tentorium cerebelli posteriorly.
Brain herniation is a potentially deadly side effect of very high pressure within the skull that occurs when a part of the brain is squeezed across structures within the skull. The brain can shift across such structures as the falx cerebri, the tentorium cerebelli, and even through the foramen magnum. Herniation can be caused by a number of factors that cause a mass effect and increase intracranial pressure (ICP): these include traumatic brain injury, intracranial hemorrhage, or brain tumor.
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 petrosal sinus is one of the dural venous sinuses located beneath the brain. It receives blood from the cavernous sinus and passes backward and laterally to drain into the transverse sinus. The sinus receives superior petrosal veins, some cerebellar veins, some inferior cerebral veins, and veins from the tympanic cavity. They may be affected by arteriovenous malformation or arteriovenous fistula, usually treated with surgery.
The falx cerebelli is a small sickle-shaped fold of dura mater projecting forwards into the posterior cerebellar notch as well as projecting into the vallecula of the cerebellum between the two cerebellar hemispheres.
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 petrous part of the temporal bone is pyramid-shaped and is wedged in at the base of the skull between the sphenoid and occipital bones. Directed medially, forward, and a little upward, it presents a base, an apex, three surfaces, and three angles, and houses in its interior the components of the inner ear. The petrous portion is among the most basal elements of the skull and forms part of the endocranium. Petrous comes from the Latin word petrosus, meaning "stone-like, hard". It is one of the densest bones in the body. In other mammals, it is a separate bone, the petrosal bone.
The squamous part of occipital bone is situated above and behind the foramen magnum, and is curved from above downward and from side to side.
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 clinoid processes are the tubercles of the sphenoid bone situated at the superior angles of the dorsum sellæ which represents the posterior boundary of the sella turcica. They vary considerably in size and form. The posterior clinoid processes deepen the sella turcica, and give attachment to the tentorium cerebelli, and the dura forming the floor of the hypophyseal fossa.
The body of the sphenoid bone, more or less cubical in shape, is hollowed out in its interior to form two large cavities, the sphenoidal sinuses, which are separated from each other by a septum.
In anatomy, the infratentorial region of the brain is the area located below the tentorium cerebelli. The area of the brain above the tentorium cerebelli is the supratentorial region. The infratentorial region contains the cerebellum, while the supratentorial region contains the cerebrum. The infratentorial dura is innervated by nerves from C1-C3.
The tentorial notch refers to the anterior opening between the free edge of the cerebellar tentorium and the clivus for the passage of the brainstem.
Pacchionian foramen means:
This article incorporates text in the public domain from page 874 of the 20th edition of Gray's Anatomy (1918)