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Epidural Space
In anatomy, the epidural space is the potential space between the dura mater and vertebrae (spine). The anatomy term "epidural space" has its origin in the Ancient Greek language; , "on, upon" + dura mater also known as "epidural cavity", "extradural space" or "peridural space". In humans the epidural space contains lymphatics, spinal nerve roots, loose connective tissue, adipose tissue, small arteries, dural venous sinuses and a network of internal vertebral venous plexuses. Cranial epidural space In the skull, the periosteal layer of the dura mater adheres to the inner surface of the skull bones while the meningeal layer lays over the arachnoid mater. Between them is the epidural space. The two layers of the dura mater separate at several places, with the meningeal layer projecting deeper into the brain parenchyma forming fibrous septa that compartmentalize the brain tissue. At these sites, the epidural space is wide enough to house the epidural venous sinuses. There are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epidural Administration
Epidural administration (from Ancient Greek ἐπί, , upon" + ''dura mater'') is a method of medication administration in which a medicine is injected into the epidural space around the spinal cord. The epidural route is used by physicians and nurse anesthetists to administer local anesthetic agents, analgesics, diagnostic medicines such as radiocontrast agents, and other medicines such as glucocorticoids. Epidural administration involves the placement of a catheter into the epidural space, which may remain in place for the duration of the treatment. The technique of intentional epidural administration of medication was first described in 1921 by Spanish military surgeon Fidel Pagés. In the United States, over 50% of childbirths involve the use of epidural anesthesia. Epidural anaesthesia causes a loss of sensation, including pain, by blocking the transmission of signals through nerve fibres in or near the spinal cord. For this reason, epidurals are commonly used for pai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebral Hemisphere
The vertebrate cerebrum (brain) is formed by two cerebral hemispheres that are separated by a groove, the longitudinal fissure. The brain can thus be described as being divided into left and right cerebral hemispheres. Each of these hemispheres has an outer layer of grey matter, the cerebral cortex, that is supported by an inner layer of white matter. In eutherian (placental) mammals, the hemispheres are linked by the corpus callosum, a very large bundle of nerve fibers. Smaller commissures, including the anterior commissure, the posterior commissure and the fornix, also join the hemispheres and these are also present in other vertebrates. These commissures transfer information between the two hemispheres to coordinate localized functions. There are three known poles of the cerebral hemispheres: the ''occipital pole'', the '' frontal pole'', and the ''temporal pole''. The central sulcus is a prominent fissure which separates the parietal lobe from the frontal lobe and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occipital Sinus
The occipital sinus is the smallest of the dural venous sinuses. It is usually unpaired, and is sometimes altogether absent. It is situated in the attached margin of the falx cerebelli. It commences near the foramen magnum, and ends by draining into the confluence of sinuses. Occipital sinuses were discovered by Guichard Joseph Duverney. Anatomy The occipital sinus is present in around 65% of individuals. It is usually single, but occasionally paired. It is situated in the attached margin of the falx cerebelli. Course The occipital sinus commences around the margin of the foramen magnum by several small venous channels (one of which joins the terminal part of the sigmoid sinus The sigmoid sinuses (sigma- or s-shaped hollow curve), also known as the , are venous sinuses within the skull that receive blood from posterior dural venous sinus veins. Structure The sigmoid sinus is a dural venous sinus situated within the ...). It terminates by draining into the confluenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Falx Cerebelli
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 name comes from two Latin words: ''falx'', meaning "curved blade or scythe", and ''cerebellum'', meaning "little brain". Anatomy The falx cerebelli is a small midline fold of dura mater projecting anterior-ward from the skull and into the space between the cerebellar hemispheres. It generally measures between 2.8 and 4.5 cm in length, and approximately 1–2 mm in thickness. Attachments Superiorly, it (with its upwardly directed base) attaches at the midline to the posterior portion of the inferior surface of the tentorium cerebelli. Posteriorly, it attaches to the internal occipital crest; the inferior-most extremity of its posterior attachment frequently divides into two small folds that terminate at either side of the foramen magnum. An ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pituitary Gland
In vertebrate anatomy, the pituitary gland, or hypophysis, is an endocrine gland, about the size of a chickpea and weighing, on average, in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain. The hypophysis rests upon the hypophyseal fossa of the sphenoid bone in the center of the middle cranial fossa and is surrounded by a small bony cavity (sella turcica) covered by a Dura mater, dural fold (diaphragma sellae). The anterior pituitary (or adenohypophysis) is a lobe of the gland that regulates several physiological processes including stress, growth, reproduction, and lactation. The intermediate lobe synthesizes and secretes melanocyte-stimulating hormone. The posterior pituitary (or neurohypophysis) is a lobe of the gland that is functionally connected to the hypothalamus by the median eminence via a small tube called the pituitary stalk (also called the infundibular stalk or the infundibulum). Hormones secreted from the pitu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sella Turcica
The sella turcica (Latin for 'Turkish saddle') is a saddle-shaped depression in the body of the sphenoid bone of the human skull and of the skulls of other hominids including chimpanzees, gorillas and orangutans. It serves as a cephalometric landmark. The pituitary gland or hypophysis is located within the most inferior aspect of the sella turcica, the hypophyseal fossa. Structure The sella turcica is located in the sphenoid bone behind the chiasmatic groove and the tuberculum sellae. It belongs to the middle cranial fossa. The sella turcica's most inferior portion is known as the hypophyseal fossa (the "seat of the saddle"), and contains the pituitary gland (hypophysis). In front of the hypophyseal fossa is the tuberculum sellae. Completing the formation of the saddle posteriorly is the dorsum sellae, which is continuous with the clivus, inferoposteriorly. The dorsum sellae is terminated laterally by the posterior clinoid processes. Development It is widely belie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diaphragma Sellae
The diaphragma sellae or sellar diaphragm is a flat piece of dura mater with a circular hole allowing the vertical passage of the pituitary stalk. It retains the pituitary gland beneath it in the fossa hypophyseos as it almost completely roofs the fossa hypophyseos of the sella turcica, a part of the sphenoid bone. It has a posterior boundary at the dorsum sellae and an anterior boundary at the tuberculum sellae along with the two small eminences (one on either side) called the middle clinoid processes. The diaphragma sellae is innervated by the first division of the cranial trigeminal nerve. Surgical Significance Violation of the diaphragma sellae during an endoscopic endonasal transsphenoidal pituitary tumor resection will result in a cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates. CSF is produced by specialised ependymal cells in the choroid plexus of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Petrosal Sinus
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. Structure The superior petrosal sinus is located beneath the brain. It originates from the cavernous sinus. It passes backward and laterally to drain into the transverse sinus. The sinus runs in the attached margin of the tentorium cerebelli, in a groove in the petrous part of the temporal bone formed by the sinus itself - the superior petrosal sulcus. Function The superior petrosal sinus drains many veins of the brain, including superior petrosal veins, some cerebellar veins, some inferior cerebral veins, and veins from the tympanic cavit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Straight Sinus
The straight sinus, also known as tentorial sinus or the , 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. Structure The straight sinus is situated within the dura mater, where the falx cerebri meets the midline of tentorium cerebelli. It forms from the confluence of the inferior sagittal sinus and the great cerebral vein. It may also drain blood from the superior cerebellar veins and veins from the falx cerebri. In cross-section, it is triangular, contains a few transverse bands across its interior, and increases in size as it proceeds backward. It is usually around 5 cm long. Variation The straight sinus is usually an unpaired structure. However, there may be two straight sinuses, which may be one on top of the other or parallel. Function The straight sinus allows blood to drain from the inferior center of the head outwards posteriorly. It receives ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transverse Sinuses
The transverse sinuses (left and right lateral 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 (by the internal occipital protuberance) to the sigmoid sinuses, which ultimately connect to the internal jugular vein. ''See diagram (at right)'': labeled under the brain as "" (for Latin: ''sinus transversus''). Structure The transverse sinuses are of large size and begin at the internal occipital protuberance; one, generally the right, being the direct continuation of the superior sagittal sinus, the other of the straight sinus. Each transverse sinus passes lateral and forward, describing a slight curve with its convexity upward, to the base of the petrous portion of the temporal bone, and lies, in this part of its course, in the attached margin of the tentorium cerebelli; it then leave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebellum
The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebellum plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language as well as emotional control such as regulating fear and pleasure responses, but its movement-related functions are the most solidly established. The human cerebellum does not initiate movement, but contributes to coordination, precision, and accurate timing: it receives input from sensory systems of the spinal cord and from other parts of the brain, and integrates these inputs to fine-tune motor activity. Cerebellar damage produces disorders in fine movement, equilibrium, posture, and motor learning in humans. Anatomically, the human cerebellum has the appearance of a separate structure attached to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebellar Tentorium
The cerebellar tentorium or tentorium cerebelli (Latin for "tent of the cerebellum") is an extension of the dura mater that separates the cerebellum from the inferior portion of the occipital lobes. Structure The cerebellar tentorium is an arched lamina, elevated in the middle, and inclining downward toward the circumference. It covers the top of the cerebellum, and supports the occipital lobes of the brain. Its anterior border is free and concave, and bounds a large oval opening, the tentorial incisure, through which pass the cerebral peduncles. 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. At the apex of the petrous part of the temporal bone the free and attached borders meet, and, crossing one another, are continued forward to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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