|
Fossa Navicularis Magna
Fossa navicularis magna (also known as ''pharyngeal fossa'' or ''phyaryngeal fovela'') is a variant bony depression found at the midline of the occipital part of clivus. This fossa was first described by Tourtual. Its prevalence ranges from 0.9 to 5.3%. Structure Fossa navicularis magna is located on the anterior surface or pharyngeal surface of the clivus. Its position when present is between the spheno-occipital synchondrosis and the foramen magnum. Size of this fossa varies considerably and its depth ranges from 3.49 to 4.94 mm. A histological study reported the presence of loose connective tissue containing collagen and elastic fibers within the fossa navicularis magna. Development Two theories have been proposed to explain the formation of fossa navicularis magna. It is believed that the fossa is formed as a remnant of the notochord or residue of the channels for emissary veins. Clinical significance Different pathologies were found associated with fossa navicularis m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossa Navicularis Magna CT
Fossa may refer to: Animals * Fossa (animal), the common name of a carnivoran mammal of genus ''Cryptoprocta'' endemic to Madagascar * ''Fossa'', the Latin genus name of the Malagasy civet, a related but smaller mammal endemic to Madagascar Places * Fossa, Abruzzo, a town in Italy * Fossa, County Kerry, a village in Ireland * Fossá, Faroe Islands, an abandoned village * Fossá, a waterfall in the Faroe islands * Fossa (river), Iceland Other uses * Fossa (anatomy), a depression in part of the body * Fossa (geology), a depression in a planet * La Fossa, an Italian rap group * Fossa (drowning pit): for executions See also * Fosse (other) Fosse a ditch or moat, may also refer to: Places * Fossé, Ardennes, a commune in France * Fosse, Belgium, a district of the municipality of Trois-Ponts, Wallonia * Fossé, Loir-et-Cher, a commune in central France * Fosse, Pyrénées-Orient ... * Fossato (other) {{Disambiguation, geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clivus (anatomy)
The clivus (, Latin for "slope"), or Blumenbach clivus, is a bony part of the cranium at the base of the skull. It is a shallow depression behind the dorsum sellae of the sphenoid bone. It slopes gradually to the anterior part of the basilar occipital bone at its junction with the sphenoid bone. It extends to the foramen magnum. It is related to the pons and the abducens nerve (CN VI). Structure The clivus is a shallow depression behind the dorsum sellae of the sphenoid bone. It slopes gradually to the anterior part of the basilar occipital bone at its junction with the sphenoid bone. Synchondrosis of these two bones forms the clivus. The clivus extends inferiorly to the foramen magnum. On axial planes, it sits just posterior to the sphenoid sinuses. It is medial to the foramen lacerum (the internal carotid artery reaches the middle cranial fossa above the foramen lacerum), proximal to its anastomosis with the Circle of Willis. It is anterior to the basilar artery. On sagi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synchondrosis and A synchondrosis (or primary cartilaginous joint) is a type of cartilaginous joint where hyaline cartilage completely joins together two bones. Synchondroses are different than symphyses (secondary cartilaginous joints) which are formed of fibrocartilage. Synchondroses are immovable joints and are thus referred to as synarthroses. Examples in the human body Permanent synchondroses * first sternocostal joint (where first rib meets the manubrium of the sternum) *petro-occipital synchondrosis Temporary synchondroses (fuse during development) *epiphyseal plates * apophyses * synchondroses in the developing hip bone composed of the ilium, ischium The ischium () form ... [...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] |
Collagen
Collagen () is the main structural protein in the extracellular matrix found in the body's various connective tissues. As the main component of connective tissue, it is the most abundant protein in mammals, making up from 25% to 35% of the whole-body protein content. Collagen consists of amino acids bound together to form a triple helix of elongated fibril known as a collagen helix. It is mostly found in connective tissue such as cartilage, bones, tendons, ligaments, and skin. Depending upon the degree of mineralization, collagen tissues may be rigid (bone) or compliant (tendon) or have a gradient from rigid to compliant (cartilage). Collagen is also abundant in corneas, blood vessels, the gut, intervertebral discs, and the dentin in teeth. In muscle tissue, it serves as a major component of the endomysium. Collagen constitutes one to two percent of muscle tissue and accounts for 6% of the weight of the skeletal muscle tissue. The fibroblast is the most common cell tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elastic Fiber
Elastic fibers (or yellow fibers) are an essential component of the extracellular matrix composed of bundles of proteins ( elastin) which are produced by a number of different cell types including fibroblasts, endothelial, smooth muscle, and airway epithelial cells. These fibers are able to stretch many times their length, and snap back to their original length when relaxed without loss of energy. Elastic fibers include elastin, elaunin and oxytalan. Elastic tissue is classified as "connective tissue proper". Elastic fibers are formed via elastogenesis, a highly complex process involving several key proteins including fibulin-4, fibulin-5, latent transforming growth factor β binding protein 4, and microfibril associated protein 4. In this process tropoelastin, the soluble monomeric precursor to elastic fibers is produced by elastogenic cells and chaperoned to the cell surface. Following excretion from the cell, tropoelastin self associates into ~200 nm particles by c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Notochord
In anatomy, the notochord is a flexible rod which is similar in structure to the stiffer cartilage. If a species has a notochord at any stage of its life cycle (along with 4 other features), it is, by definition, a chordate. The notochord consists of inner, vacuolated cells covered by fibrous and elastic sheaths, lies along the anteroposterior axis (''front to back''), is usually closer to the dorsal than the ventral surface of the embryo, and is composed of cells derived from the mesoderm. The most commonly cited functions of the notochord are: as a midline tissue that provides directional signals to surrounding tissue during development, as a skeletal (structural) element, and as a vertebral precursor. In lancelets the notochord persists throughout life as the main structural support of the body. In tunicates the notochord is present only in the larval stage, being completely absent in the adult animal. In these invertebrate chordates, the notochord is not vacuolated ... [...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 bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tornwaldt Cyst
A Tornwaldt cyst also spelt as Thornwaldt or Thornwald cyst is a benign cyst located in the upper posterior nasopharynx. It can be seen on computed tomography (CT) or magnetic resonance imaging Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio wave ... (MRI) of the head as a well-circumscribed round mass lying in the midline. In most cases, treatment is not necessary. It was first described by Gustav Ludwig Tornwaldt. See also * Tornwaldt's disease References External links {{Commons category, Tornwaldt's cyst Cysts Human throat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Craniopharyngeal Canal
The craniopharyngeal canal is a human anatomical feature sometimes found in the sphenoid bone opening to the sella turcica. It is a canal (a passage or channel) sometimes found extending from the anterior part of the fossa hypophyseos of the sphenoid bone to the under surface of the skull, and marks the original position of Rathke's pouch; while at the junction of the septum of the nose with the palate The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly s ... traces of the stomodeal end are occasionally present. This canal is found in 0.4% of individuals. References *''Dorland's Illustrated Medical Dictionary'', 27th ed. 1988 W.B. Saunders Company. Philadelphia, PA. Bones of the head and neck {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatomical Variations
An anatomical variation, anatomical variant, or anatomical variability is a presentation of body structure with morphological features different from those that are typically described in the majority of individuals. Anatomical variations are categorized into three types including morphometric (size or shape), consistency (present or absent), and spatial (proximal/distal or right/left). Variations are seen as normal in the sense that they are found consistently among different individuals, are mostly without symptoms, and are termed anatomical variations rather than abnormalities. Anatomical variations are mainly caused by genetics and may vary considerably between different populations. The rate of variation considerably differs between single organs, particularly in muscles. Knowledge of anatomical variations is important in order to distinguish them from pathological conditions. A very early paper published in 1898, presented anatomic variations to have a wide range and signi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.svg "Click for more on -> Collagen")
