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Dural Sinus
The dural venous sinuses (also called dural sinuses, cerebral sinuses, or cranial sinuses) are venous sinuses (channels) found between the periosteal and meningeal layers of dura mater in the brain. They receive blood from the cerebral veins, and cerebrospinal fluid (CSF) from the subarachnoid space via arachnoid granulations. They mainly empty into the internal jugular vein. Cranial venous sinuses communicate with veins outside the skull through emissary veins. These communications help to keep the pressure of blood in the sinuses constant. The major dural venous sinuses included the superior sagittal sinus, inferior sagittal sinus, transverse sinus, straight sinus, sigmoid sinus and cavernous sinus. These sinuses play a crucial role in cerebral venous drainage. A dural venous sinus, in human anatomy, is any of the channels of a branching complex sinus network that lies between layers of the dura mater, the outermost covering of the brain, and functions to collect oxygen-de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vein
Veins () are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal circulations which carry oxygenated blood to the heart. In the systemic circulation, arteries carry oxygenated blood away from the heart, and veins return deoxygenated blood to the heart, in the deep veins. There are three sizes of veins: large, medium, and small. Smaller veins are called venules, and the smallest the post-capillary venules are microscopic that make up the veins of the microcirculation. Veins are often closer to the skin than arteries. Veins have less smooth muscle and connective tissue and wider internal diameters than arteries. Because of their thinner walls and wider lumens they are able to expand and hold more blood. This greater capacity gives them the term of ''capacitance vessels''. At any time, nearly 70% o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Sagittal Sinus
The inferior sagittal sinus (also known as inferior longitudinal sinus), within the human head, is an area beneath the brain which allows blood to drain outwards posteriorly from the center of the head. It drains (from the center of the brain) to the straight sinus (at the back of the head), which connects to the transverse sinuses. ''See diagram (at right)'': labeled in the brain as "" (for Latin: ''sinus sagittalis inferior''). The inferior sagittal sinus courses along the inferior border of the falx cerebri, superior to the corpus callosum. It receives blood from the deep and medial aspects of the cerebral hemispheres and drains into the straight sinus. Additional images File:Gray568.png, Sagittal section of the skull, showing the sinuses of the dura. File:Human brain dura mater (reflections) description.JPG, Human brain dura mater (reflections) See also * Dural venous sinuses The dural venous sinuses (also called dural sinuses, cerebral sinuses, or cranial sinuses) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artery
An artery () is a blood vessel in humans and most other animals that takes oxygenated blood away from the heart in the systemic circulation to one or more parts of the body. Exceptions that carry deoxygenated blood are the pulmonary arteries in the pulmonary circulation that carry blood to the lungs for oxygenation, and the umbilical arteries in the fetal circulation that carry deoxygenated blood to the placenta. It consists of a multi-layered artery wall wrapped into a tube-shaped channel. Arteries contrast with veins, which carry deoxygenated blood back towards the heart; or in the pulmonary and fetal circulations carry oxygenated blood to the lungs and fetus respectively. Structure The anatomy of arteries can be separated into gross anatomy, at the macroscopic scale, macroscopic level, and histology, microanatomy, which must be studied with a microscope. The arterial system of the human body is divided into systemic circulation, systemic arteries, carrying blood from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tunica Media
The tunica media (Neo-Latin "middle coat"), or media for short, is the middle tunica (layer) of an artery or vein. It lies between the internal elastic lamina of the tunica intima on the inside and the tunica externa on the outside. Artery The tunica media is made up of smooth muscle cells, elastic tissue and collagen. It lies between the tunica intima on the inside and the tunica externa on the outside. The middle coat (tunica media) is distinguished from the inner (tunica intima) by its color and by the transverse arrangement of its fibers. * In the ''smaller arteries'', it consists principally of smooth muscle fibers in fine bundles, arranged in lamellae and disposed circularly around the vessel. These lamellae vary in number according to the size of the vessel; the smallest arteries having only a single layer, and those slightly larger three or four layers - up to a maximum of six layers. It is to this coat that the thickness of the wall of the artery is mainly due. * I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lymph Vessel
The lymphatic vessels (or lymph vessels or lymphatics) are thin-walled vessels (tubes), structured like blood vessels, that carry lymph. As part of the lymphatic system, lymph vessels are complementary to the cardiovascular system. Lymph vessels are lined by endothelial cells, and have a thin layer of smooth muscle, and adventitia that binds the lymph vessels to the surrounding tissue. Lymph vessels are devoted to the propulsion of the lymph from the lymph capillaries, which are mainly concerned with the absorption of interstitial fluid from the tissues. Lymph capillaries are slightly bigger than their counterpart capillaries of the vascular system. Lymph vessels that carry lymph to a lymph node are called afferent lymph vessels, and those that carry it from a lymph node are called efferent lymph vessels, from where the lymph may travel to another lymph node, may be returned to a vein, or may travel to a larger lymph duct. Lymph ducts drain the lymph into one of the subclavian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Vessel
Blood vessels are the tubular structures of a circulatory system that transport blood throughout many Animal, animals’ bodies. Blood vessels transport blood cells, nutrients, and oxygen to most of the Tissue (biology), tissues of a Body (biology), body. They also take waste and carbon dioxide away from the tissues. Some tissues such as cartilage, epithelium, and the lens (anatomy), lens and cornea of the eye are not supplied with blood vessels and are termed ''avascular''. There are five types of blood vessels: the arteries, which carry the blood away from the heart; the arterioles; the capillaries, where the exchange of water and chemicals between the blood and the tissues occurs; the venules; and the veins, which carry blood from the capillaries back towards the heart. The word ''vascular'', is derived from the Latin ''vas'', meaning ''vessel'', and is mostly used in relation to blood vessels. Etymology * artery – late Middle English; from Latin ''arteria'', from Gree ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squamous Cell
Epithelium or epithelial tissue is a thin, continuous, protective layer of Cell (biology), cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial (Mesothelium, mesothelial) tissues line the outer surfaces of many internal organ (anatomy), organs, the corresponding inner surfaces of body cavities, and the inner surfaces of blood vessels. Epithelial tissue is one of the four basic types of animal Tissue (biology), tissue, along with connective tissue, muscle tissue and nervous tissue. These tissues also lack blood or lymph supply. The tissue is supplied by nerves. There are three principal shapes of epithelial cell: squamous (scaly), columnar, and cuboidal. These can be arranged in a singular layer of cells as simple epithelium, either simple squamous, simple columnar, or simple cuboidal, or in layers of two or more cells deep as stratified (layered), or ''compound'', either squamous, columnar or cuboidal. In some tissues, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endothelium
The endothelium (: endothelia) is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. Endothelial cells in direct contact with blood are called vascular endothelial cells whereas those in direct contact with lymph are known as lymphatic endothelial cells. Vascular endothelial cells line the entire circulatory system, from the heart to the smallest capillaries. These cells have unique functions that include fluid filtration, such as in the glomerulus of the kidney, blood vessel tone, hemostasis, neutrophil recruitment, and hormone trafficking. Endothelium of the interior surfaces of the heart chambers is called endocardium. An impaired function can lead to serious health issues throughout the body. Structure The endothelium is a thin layer of single flat (squamous) cells that line the inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sigmoid Sinuses
The sigmoid sinuses (sigma- or s-shaped hollow curve), also known as the , are paired dural venous sinuses within the skull that receive blood from posterior transverse sinuses. 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. Refe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Petrosal Sinus
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. Structure The inferior petrosal sinus is situated in the inferior petrosal sulcus, formed by the junction of the petrous part of the temporal bone with the basilar part of the occipital bone. It begins below and behind the cavernous sinus and, passing through the anterior part of the jugular foramen, ends in the superior bulb of the internal jugular vein. Function The inferior petrosal sinus receives the internal auditory veins and also veins from the medulla oblongata, pons, and under surface of the cerebellum. Additional images File:Gray568.png, Sagittal section of the skull, showing the sinuses of the dura. See also * Dural venous sinuses The dural venous sinuses (also called dural sinuses, cerebral sinuses, or cranial sinuses) are veno ... [...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'' https://www.ncbi.nlm.nih.gov/books/NBK482257] 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 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 c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
