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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 * Occipital sinus * Superficial veins of the brain Within the human brain, the superficial v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dura Mater
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. Structure The dura mater has several functions and layers. The dura mater is a membrane that envelops the arachnoid mater. It surrounds and supports the dural sinuses (also called dural venous sinuses, cerebral sinuses, or cranial sinuses) and carries blood from the brain toward the heart. Cranial dura mater has two layers called ''lamellae'', a superficial layer (also called the periosteal layer), which serves as the skull's inner periosteum, called the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Skull
The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, these two parts are the neurocranium and the viscerocranium ( facial skeleton) that includes the mandible as its largest bone. The skull forms the anterior-most portion of the skeleton and is a product of cephalisation—housing the brain, and several sensory structures such as the eyes, ears, nose, and mouth. In humans these sensory structures are part of the facial skeleton. Functions of the skull include protection of the brain, fixing the distance between the eyes to allow stereoscopic vision, and fixing the position of the ears to enable sound localisation of the direction and distance of sounds. In some animals, such as horned ungulates (mammals with hooves), the skull also has a defensive function by providing the mount (on the front ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brain
A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a vertebrate's body. In a human, the cerebral cortex contains approximately 14–16 billion neurons, and the estimated number of neurons in the cerebellum is 55–70 billion. Each neuron is connected by synapses to several thousand other neurons. These neurons typically communicate with one another by means of long fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body targeting specific recipient cells. Physiologically, brains exert centralized control over a body's other organs. They act on the rest of the body both by generating patterns of muscle activity and by driving the secretion of chemicals called hormones. This centralized control allows rapid and coordinated respon ... [...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 blo ... [...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 leaves th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Falx Cerebri
The falx cerebri (also known as the cerebral falx) is a large, crescent-shaped fold of dura mater that descends vertically into the longitudinal fissure between the cerebral hemispheres of the human brain,Saladin K. "Anatomy & Physiology: The Unity of Form and Function. New York: McGraw Hill, 2014. Print. pp 512, 770-773 separating the two hemispheres and supporting dural sinuses that provide venous and CSF drainage to the brain. The falx cerebri is often subject to age-related calcification, and a site of falcine meningiomas. The falx cerebri is named for its sickle-like form. Anatomy The falx cerebri is a strong, crescent-shaped sheet lying in the sagittal plane. It is a dural formation (one of four dural partitions of the brain along with the falx cerebelli, tentorium cerebelli, and diaphragma sellae); it is formed through invagination of the dura mater into the longitudinal fissure between the cerebral hemispheres. Anteriorly, the falx cerebri is narrower, thinner, and m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corpus Callosum
The corpus callosum (Latin for "tough body"), also callosal commissure, is a wide, thick nerve tract, consisting of a flat bundle of commissural fibers, beneath the cerebral cortex in the brain. The corpus callosum is only found in placental mammals. It spans part of the longitudinal fissure, connecting the left and right cerebral hemispheres, enabling communication between them. It is the largest white matter structure in the human brain, about in length and consisting of 200–300 million axonal projections. A number of separate nerve tracts, classed as subregions of the corpus callosum, connect different parts of the hemispheres. The main ones are known as the genu, the rostrum, the trunk or body, and the splenium. Structure The corpus callosum forms the floor of the longitudinal fissure that separates the two cerebral hemispheres. Part of the corpus callosum forms the roof of the lateral ventricles. The corpus callosum has four main parts – individual nerve tracts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebral Hemispheres
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 prim ... [...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] |
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] |
Superficial Veins Of The Brain
Within the human brain, the superficial veins of the brain are those veins that are close to the surface of the brain. They consist of a superior group that empties into the superior sagittal sinus and inferior sagittal sinus, and an inferior group which empties into the transverse sinuses and the cavernous sinuses 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. Structure The cav .... References Veins of the head and neck {{circulatory-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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