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Sphenoidal Emissary Foramen
In the base of the skull, in the great wings of the sphenoid bone, medial to the foramen ovale, a small aperture, the sphenoidal emissary foramen, may occasionally be seen (it is often absent) opposite the root of the pterygoid process. When present, it opens below near the scaphoid fossa. Vesalius was the first to describe and illustrate this foramen, and it thus sometimes bears the name of foramen Vesalii (meaning foramen of Vesalius). Other names include foramen venosum and canaliculus sphenoidalis. Importance If at all present, the sphenoidal emissary foramen gives passage to a small vein (vein of Vesalius) that connects the pterygoid plexus with the cavernous sinus. The importance of this passage lies in the fact that an infected thrombus from an extracranial source may reach the cavernous sinus. The mean area of the foramen is small, which may suggest that it plays a minor role in the dynamics of blood circulation in the venous system of the head. Structure The sph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenoid Bone
The sphenoid bone is an unpaired bone of the neurocranium. It is situated in the middle of the skull towards the front, in front of the basilar part of the occipital bone. The sphenoid bone is one of the seven bones that articulate to form the orbit. Its shape somewhat resembles that of a butterfly or bat with its wings extended. Structure It is divided into the following parts: * a median portion, known as the body of sphenoid bone, containing the sella turcica, which houses the pituitary gland as well as the paired paranasal sinuses, the sphenoidal sinuses * two greater wings on the lateral side of the body and two lesser wings from the anterior side. * Pterygoid processes of the sphenoides, directed downwards from the junction of the body and the greater wings. Two sphenoidal conchae are situated at the anterior and inferior part of the body. Intrinsic ligaments of the sphenoid The more important of these are: * the pterygospinous, stretching between the spina angu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cavernous Sinus
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 cavernous sinus is one of the dural venous sinuses of the head. It is a network of veins that sit in a cavity. It sits on both sides of the sphenoidal bone and pituitary gland, approximately 1 × 2 cm in size in an adult. The carotid siphon of the internal carotid artery, and cranial nerves III, IV, V (branches V1 and V2) and VI all pass through this blood filled space. Both sides of cavernous sinus is connected to each other via intercavernous sinuses. The cavernous sinus lies in between the inner and outer layers of dura mater. Nearby structures * Above: optic tract, optic chiasma, internal carotid artery. * Inferiorly: foramen lacerum, and the junction of the body and greater wing of sphenoid bone. * Medially: pituitary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurofibromatosis
Neurofibromatosis (NF) is a group of three conditions in which tumors grow in the nervous system. The three types are neurofibromatosis type I (NF1), neurofibromatosis type II (NF2), and schwannomatosis. In NF1 symptoms include light brown spots on the skin, freckles in the armpit and groin, small bumps within nerves, and scoliosis. In NF2, there may be hearing loss, cataracts at a young age, balance problems, flesh colored skin flaps, and muscle wasting. In schwannomatosis there may be pain either in one location or in wide areas of the body. The tumors in NF are generally non-cancerous. The cause is a genetic mutation in certain oncogenes. These can be inherited from a person's parents, or in about half of cases spontaneously occur during early development. Different mutations result in the three types of NF. Neurofibromatosis arise from the supporting cells of the nervous system rather than the neurons themselves. In NF1, the tumors are neurofibromas (tumors of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emissary Veins
The emissary veins connect the extracranial venous system with the intracranial venous sinuses. They connect the veins outside the cranium to the venous sinuses inside the cranium. They drain from the scalp, through the skull, into the larger meningeal veins and dural venous sinuses. Emissary veins have an important role in selective cooling of the head. They also serve as routes where infections are carried into the cranial cavity from the extracranial veins to the intracranial veins. There are several types of emissary veins including posterior condyloid, mastoid, occipital and parietal emissary vein. Structure There are also emissary veins passing through the foramen ovale, jugular foramen, foramen lacerum, and hypoglossal canal. Function Because the emissary veins are valveless, they are an important part in selective brain cooling through bidirectional flow of cooler blood from the evaporating surface of the head. In general, blood flow is from external to internal but t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carotid-cavernous Fistula
A carotid-cavernous fistula results from an abnormal communication between the arterial and venous systems within the cavernous sinus in the skull. It is a type of arteriovenous fistula. As arterial blood under high pressure enters the cavernous sinus, the normal venous return to the cavernous sinus is impeded and this causes engorgement of the draining veins, manifesting most dramatically as a sudden engorgement and redness of the eye of the same side. Presentation CCF symptoms include bruit (a humming sound within the skull due to high blood flow through the arteriovenous fistula), progressive visual loss, and pulsatile proptosis Exophthalmos (also called exophthalmus, exophthalmia, proptosis, or exorbitism) is a bulging of the eye anteriorly out of the orbit. Exophthalmos can be either bilateral (as is often seen in Graves' disease) or unilateral (as is often seen i ... or progressive bulging of the eye due to dilatation of the veins draining the eye. Pain is the sympto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Circulation
The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels (from Greek ''kardia'' meaning ''heart'', and from Latin ''vascula'' meaning ''vessels''). The circulatory system has two divisions, a systemic circulation or circuit, and a pulmonary circulation or circuit. Some sources use the terms ''cardiovascular system'' and ''vascular system'' interchangeably with the ''circulatory system''. The network of blood vessels are the great vessels of the heart including large elastic arteries, and large veins; other arteries, smaller arterioles, capillaries that join with venules (small veins), and other veins. The circulatory system is closed in vertebrates, which means that the blood never leaves the network of blood vessels. Some invertebrates such as art ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrombus
A thrombus (plural thrombi), colloquially called a blood clot, is the final product of the blood coagulation step in hemostasis. There are two components to a thrombus: aggregated platelets and red blood cells that form a plug, and a mesh of cross-linked fibrin protein. The substance making up a thrombus is sometimes called cruor. A thrombus is a healthy response to injury intended to stop and prevent further bleeding, but can be harmful in thrombosis, when a clot obstructs blood flow through healthy blood vessels in the circulatory system. In the microcirculation consisting of the very small and smallest blood vessels the capillaries, tiny thrombi known as microclots can obstruct the flow of blood in the capillaries. This can cause a number of problems particularly affecting the alveoli in the lungs of the respiratory system resulting from reduced oxygen supply. Microclots have been found to be a characteristic feature in severe cases of COVID-19, and in long COVID. Mur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterygoid Plexus
The pterygoid plexus (; in Merriam-Webster Online Dictionary '. from ''pteryx'', "wing" and ''eidos'', "shape") is a of considerable size, and is situated between the and lateral pter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base Of The Skull
The base of skull, also known as the cranial base or the cranial floor, is the most inferior area of the skull. It is composed of the endocranium and the lower parts of the calvaria. Structure Structures found at the base of the skull are for example: Bones There are five bones that make up the base of the skull: * Ethmoid bone *Sphenoid bone *Occipital bone *Frontal bone *Temporal bone Sinuses * Occipital sinus * Superior sagittal sinus * Superior petrosal sinus Foramina of the skull * Foramen cecum * Optic foramen * Foramen lacerum * Foramen rotundum *Foramen magnum * Foramen ovale * Jugular foramen * Internal auditory meatus * Mastoid foramen * Sphenoidal emissary foramen * Foramen spinosum Sutures * Frontoethmoidal suture * Sphenofrontal suture * Sphenopetrosal suture *Sphenoethmoidal suture * Petrosquamous suture *Sphenosquamosal suture Other * Sphenoidal lingula * Subarcuate fossa *Dorsum sellae * Jugular process * Petro-occipital fissure * Condylar canal * Jug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vesalius
Andreas Vesalius (Latinized from Andries van Wezel) () was a 16th-century anatomist, physician, and author of one of the most influential books on human anatomy, ''De Humani Corporis Fabrica Libri Septem'' (''On the fabric of the human body'' ''in seven books''). Vesalius is often referred to as the founder of modern human anatomy. He was born in Brussels, which was then part of the Habsburg Netherlands. He was a professor at the University of Padua (1537–1542) and later became Imperial physician at the court of Emperor Charles V. ''Andreas Vesalius'' is the Latinized form of the Dutch name Andries van Wesel. It was a common practice among European scholars in his time to Latinize their names. His name is also given as ''Andrea Vesalius'', ''André Vésale'', ''Andrea Vesalio'', ''Andreas Vesal'', ''Andrés Vesalio'' and ''Andre Vesale''. Early life and education Vesalius was born as Andries van Wesel to his father Anders van Wesel and mother Isabel Crabbe on 31 December 151 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scaphoid Fossa
In the pterygoid processes of the sphenoid, above the pterygoid fossa is a small, oval, shallow depression, the scaphoid fossa, which gives origin to the Tensor veli palatini The tensor veli palatini muscle (tensor palati or tensor muscle of the velum palatinum) is a broad, thin, ribbon-like muscle in the head that tenses the soft palate. Structure The tensor veli palatini is found anterior-lateral to the levator ve .... It is not the same as and has to be distinguished from the scaphoid fossa of the external ear or pinna. References External links Diagram - look for #28(sourchere Bones of the head and neck {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
