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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). It terminates by draining into the confluence of the sinuses. Communications The occipital sinus communicates with the marginal sinus Marginal may refer to: * ''Marginal'' (album), the third album of the Belgian rock band Dead Man Ray, released in 2001 * ''Marginal'' (manga) * '' El Marginal'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Confluence Of Sinuses
The confluence of sinuses (Latin: confluens sinuum), 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. Structure The confluence of sinuses is found deep to the internal occipital protuberance of the occipital bone of the skull. This puts it inferior to the occipital lobes of the brain, and posterosuperior to the cerebellum. It connects the ends of the superior sagittal sinus, the straight sinus, and the occipital sinus. Blood from it can drain into the left and right transverse sinuses. It is lined with endothelium, with some smooth muscle. Variation The confluence of sinuses shows significant variation. Most commonly, there is a conti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dural Venous Sinuses
The dural venous sinuses (also called dural sinuses, cerebral sinuses, or cranial 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. Venous sinuses Structure The walls of the dural venous sinuses are composed of dura mater lined with endothelium, a specialized layer of flattened cells found in blood vessels. They differ from other blood vessels in that they lack a full set of vessel layers (e.g. tunica media) characteristic of arteries and veins. It also lacks valves (in veins; with exception of materno-fetal blood circulation i.e. placental artery and pulmonary arteries both of which carry deoxygenated blood). Clinical relevance The sinuses can be injured by trauma in which damage to the dura mater, may result in blood clot formation (throm ... [...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. Ana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foramen Magnum
The foramen magnum ( la, great hole) is a large, oval-shaped opening in the occipital bone of the skull. It is one of the several oval or circular openings (foramina) in the base of the skull. The spinal cord, an extension of the medulla oblongata, passes through the foramen magnum as it exits the cranial cavity. Apart from the transmission of the medulla oblongata and its membranes, the foramen magnum transmits the vertebral arteries, the anterior and posterior spinal arteries, the tectorial membranes and alar ligaments. It also transmits the accessory nerve into the skull. The foramen magnum is a very important feature in bipedal mammals. One of the attributes of a biped's foramen magnum is a forward shift of the anterior border of the cerebellar tentorium; this is caused by the shortening of the cranial base. Studies on the foramen magnum position have shown a connection to the functional influences of both posture and locomotion. The forward shift of the foramen magnum i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guichard Joseph Duverney
Joseph Guichard Duverney or Joseph-Guichard Du Verney (5 August 1648 – 10 September 1730) was a French anatomist known for his work in comparative anatomy and for his treatise on the ear. The fracture of the iliac wing of the pelvis is sometimes called the Duverney fracture. Biography Du Verney was a native of Feurs in the province of Forez. His father Jacques Duverny was a doctor in the small community Feurs. His mother was born Antoinette Pittre. His two other older brothers studied medicine and he too studied at the University of Avignon, where in 1667 he obtained his medical degree. Shortly afterwards, he relocated to Paris where he was active in the circle of Abbé Pierre Michon Bourdelot where he came into contact with Claude Perrault. He became known for his assiduous anatomical dissections apart from dealing with patients. In 1676 he became the anatomist at the Royal Academy of Sciences to replace Louis Gayant (died 1673) and Jean Pecquet (died 1674). He began ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 dura mater. The sigmoid sinus receives blood from the transverse sinuses, which track the posterior wall of the cranial cavity, travels inferiorly along the parietal bone, temporal bone and occipital bone, and converges with the inferior petrosal sinuses to form the internal jugular vein. Each sigmoid sinus begins beneath the temporal bone and follows a tortuous course to the jugular foramen, at which point the sinus becomes continuous with the internal jugular vein. Function The sigmoid sinus receives blood from the transverse sinuses, which receive blood from the posterior aspect of the skull. Along its course, the sigmoid sinus also receives blood from the cerebral veins, cerebellar veins, diploic veins, and emissary veins. See als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Confluence Of The Sinuses
The confluence of sinuses (Latin: confluens sinuum), 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. Structure The confluence of sinuses is found deep to the internal occipital protuberance of the occipital bone of the skull. This puts it inferior to the occipital lobes of the brain, and posterosuperior to the cerebellum. It connects the ends of the superior sagittal sinus, the straight sinus, and the occipital sinus. Blood from it can drain into the left and right transverse sinuses. It is lined with endothelium, with some smooth muscle. Variation The confluence of sinuses shows significant variation. Most commonly, there is a conti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marginal Sinus
Marginal may refer to: * ''Marginal'' (album), the third album of the Belgian rock band Dead Man Ray, released in 2001 * ''Marginal'' (manga) * '' El Marginal'', Argentine TV series * Marginal seat or marginal constituency or marginal, in politics See also Economics * Marginalism *Marginal analysis *Marginal concepts *Marginal cost *Marginal demand *Marginal product *Marginal product of labor *Marginal propensity to consume *Marginal rate of substitution *Marginal use *Marginal utility *Marginal rate Other * Margin (other) * Marginalization * Marginal intra-industry trade, where the change in a country's exports are essentially of the same products as its change in imports * Marginal land, land that is of little value because of its unsuitability for growing crops and other uses * Marginal model, in hierarchical linear modeling * Marginal observables, in physics; see Renormalization group * Marginal person, in sociology; see Marginalization * Marginal plant, see Bog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Vertebral Venous Plexuses
The internal vertebral venous plexuses (intraspinal veins) lie within the vertebral canal in the epidural space, and receive tributaries from the bones and from the spinal cord. They form a closer network than the external plexuses, and, running mainly in a vertical direction, form four longitudinal veins, two in front and two behind; they therefore may be divided into anterior and posterior groups. * The ''anterior internal plexuses'' consist of large veins which lie on the posterior surfaces of the vertebral bodies and intervertebral fibrocartilages on either side of the posterior longitudinal ligament; under cover of this ligament they are connected by transverse branches into which the basivertebral veins open. * The ''posterior internal plexuses'' are placed, one on either side of the middle line in front of the vertebral arches and ligamenta flava, and anastomose by veins passing through those ligaments with the posterior external plexuses. The anterior and posterior plexuses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
