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Porion
''For people with the surname, see Porion (surname).'' The porion is the point on the human skull located at the upper margin of each ear canal (external auditory meatus, external acoustic meatus). It lies on the superior margin of the tragus. It is a cephalometric landmark with significance in biological anthropology and in clinical applications such as oral and maxillofacial surgery. Anatomical significance The porion is one of the three anatomical points used to determine the Frankfurt plane. The Frankfurt plane (also called the auriculo-orbital plane) was established at the World Congress on Anthropology in Frankfurt, Germany in 1884, and decreed as the anatomical position of the human skull for comparative craniometric measurements. It was decided that a plane passing through the inferior margin of the left orbit (the point called the left orbitale) and the upper margin of each ear canal or external auditory meatus, a point called the porion, was most nearly parallel to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porion (surname)
Porion is a French surname French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with France .... Notable people with the surname include: * Charles Porion (1814–1868), French painter * Louis Porion (1805–1858), French politician {{surname, Porion French-language surnames Surnames of French origin ... [...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] |
Ear Canal
The ear canal (external acoustic meatus, external auditory meatus, EAM) is a pathway running from the outer ear to the middle ear. The adult human ear canal extends from the pinna to the eardrum and is about in length and in diameter. Structure The human ear canal is divided into two parts. The elastic cartilage part forms the outer third of the canal; its anterior and lower wall are cartilaginous, whereas its superior and back wall are fibrous. The cartilage is the continuation of the cartilage framework of pinna. The cartilaginous portion of the ear canal contains small hairs and specialized sweat glands, called apocrine glands, which produce cerumen ( ear wax). The bony part forms the inner two thirds. The bony part is much shorter in children and is only a ring (''annulus tympanicus'') in the newborn. The layer of epithelium encompassing the bony portion of the ear canal is much thinner and therefore, more sensitive in comparison to the cartilaginous portion. Size and sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tragus (ear)
The tragus is a small pointed eminence of the external ear, situated in front of the concha, and projecting backward over the meatus. It also is the name of hair growing at the entrance of the ear. Its name comes the Ancient Greek (), meaning 'goat', and is descriptive of its general covering on its under surface with a tuft of hair, resembling a goat's beard. The nearby antitragus projects forwards and upwards. Because the tragus faces rearwards, it aids in collecting sounds from behind. These sounds are delayed more than sounds arriving from the front, assisting the brain to sense front vs. rear sound sources. In a positive fistula test (for the presence of a fistula from cholesteatoma to the labyrinth), pressure on the tragus causes vertigo or eye deviation by inducing movement of perilymph. Other animals The tragus is a key feature in many bat species. As a piece of skin in front of the ear canal, it plays an important role in directing sounds into the ear for prey locati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalometric Analysis
Cephalometric analysis is the clinical application of cephalometry. It is analysis of the dental and skeletal relationships of a human skull. It is frequently used by dentists, orthodontists, and oral and maxillofacial surgeons as a treatment planning tool. Two of the more popular methods of analysis used in orthodontology are the Steiner analysis (named after Cecil C. Steiner) and the Downs analysis (named after William B. Downs). There are other methods as well which are listed below. Cephalometric radiographs Cephalometric analysis depends on cephalometric radiography to study relationships between bony and soft tissue landmarks and can be used to diagnose facial growth abnormalities prior to treatment, in the middle of treatment to evaluate progress, or at the conclusion of treatment to ascertain that the goals of treatment have been met. A Cephalometric radiograph is a radiograph of the head taken in a Cephalometer (Cephalostat) that is a head-holding device introduced ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Anthropology
Biological anthropology, also known as physical anthropology, is a scientific discipline concerned with the biological and behavioral aspects of human beings, their extinct hominin ancestors, and related non-human primates, particularly from an evolutionary perspective. This subfield of anthropology systematically studies human beings from a biological perspective. Branches As a subfield of anthropology, biological anthropology itself is further divided into several branches. All branches are united in their common orientation and/or application of evolutionary theory to understanding human biology and behavior. * Bioarchaeology is the study of past human cultures through examination of human remains recovered in an archaeological context. The examined human remains usually are limited to bones but may include preserved soft tissue. Researchers in bioarchaeology combine the skill sets of human osteology, paleopathology, and archaeology, and often consider the cultural and mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frankfurt Plane
The standard anatomical position, or standard anatomical model, is the scientifically agreed upon reference position for anatomical location terms. Standard anatomical positions are used to standardise the position of appendages of animals with respect to the main body of the organism. In medical disciplines, all references to a location on or in the body are made based upon the standard anatomical position. A straight position is assumed when describing a proximo-distal axis (towards or away from a point of attachment). This helps avoid confusion in terminology when referring to the same organism in different postures. For example, if the elbow is flexed, the hand remains distal to the shoulder even if it approaches the shoulder. Human anatomy In standard anatomical position, the human body is standing erect and at rest. Unlike the situation in other vertebrates, the limbs are placed in positions reminiscent of the supine position imposed on cadavers during autopsy. Therefo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbit (anatomy)
In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents. In the adult human, the volume of the orbit is , of which the eye occupies . The orbital contents comprise the eye, the orbital and retrobulbar fascia, extraocular muscles, cranial nerves II, III, IV, V, and VI, blood vessels, fat, the lacrimal gland with its sac and duct, the eyelids, medial and lateral palpebral ligaments, cheek ligaments, the suspensory ligament, septum, ciliary ganglion and short ciliary nerves. Structure The orbits are conical or four-sided pyramidal cavities, which open into the midline of the face and point back into the head. Each consists of a base, an apex and four walls."eye, human."Encyclopædia Britannica from Encyclopædia Britannica 2006 Ultimate Reference Suite DVD 2009 Openings There are two important foramina, or windows, two important fissu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surface is made up of the ocean, dwarfing Earth's polar ice, lakes, and rivers. The remaining 29% of Earth's surface is land, consisting of continents and islands. Earth's surface layer is formed of several slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Earth's liquid outer core generates the magnetic field that shapes the magnetosphere of the Earth, deflecting destructive solar winds. The atmosphere of the Earth consists mostly of nitrogen and oxygen. Greenhouse gases in the atmosphere like carbon dioxide (CO2) trap a part of the energy from the Sun close to the surface. Water vapor is widely present in the atmosphere and forms clouds that cover most of the planet. More solar e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbit (anatomy)
In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents. In the adult human, the volume of the orbit is , of which the eye occupies . The orbital contents comprise the eye, the orbital and retrobulbar fascia, extraocular muscles, cranial nerves II, III, IV, V, and VI, blood vessels, fat, the lacrimal gland with its sac and duct, the eyelids, medial and lateral palpebral ligaments, cheek ligaments, the suspensory ligament, septum, ciliary ganglion and short ciliary nerves. Structure The orbits are conical or four-sided pyramidal cavities, which open into the midline of the face and point back into the head. Each consists of a base, an apex and four walls."eye, human."Encyclopædia Britannica from Encyclopædia Britannica 2006 Ultimate Reference Suite DVD 2009 Openings There are two important foramina, or windows, two important fissu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asterion (anatomy)
The asterion is a meeting point between three sutures between bones of the skull. It is an important surgical landmark. Structure In human anatomy, the asterion is a visible ( craniometric) point on the exposed skull. It is just posterior to the ear. It is the point where three cranial sutures meet: * the lambdoid suture. * parietomastoid suture. * occipitomastoid suture. It is also the point where three cranial bones meet: * the parietal bone. * the occipital bone. * the mastoid portion of the temporal bone. In the adult, it lies 4 cm behind and 12 mm above the center of the entrance to the ear canal. Its relation to other anatomical structures is fairly variable. Clinical significance Neurosurgeons may use the asterion to orient themselves, in order to plan safe entry into the skull for some operations, such as when using a retro-sigmoid approach. Etymology The asterion receives its name from the Greek ἀστέριον (''astērion''), meaning "star" or "starry" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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