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Nasal Cycle
The nasal cycle is the unconscious alternating partial congestion and decongestion of the nasal cavities in humans and other animals. This results in greater airflow through one nostril with periodic alternation between the nostrils. It is a physiological congestion of the nasal conchae, also called the nasal turbinates (curled bony projections within the nasal cavities), due to selective activation of one half of the autonomic nervous system by the hypothalamus. It should not be confused with pathological nasal congestion. Description The nasal cycle was studied and discussed in the ancient Indian yoga of literature of pranayama. In the modern western literature, it was first described by the German physician Richard Kayser in 1895. In 1927, Heetderks described the alternating turgescence of the inferior turbinates in 80% of a normal population. According to Heetderks, the cycle is the result of alternating congestion and decongestion of the nasal conchae or turbinates, pr ...
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Concha Nasalis
In anatomy, a nasal concha (), plural conchae (), also called a nasal turbinate or turbinal, is a long, narrow, curled shelf of bone that protrudes into the breathing passage of the nose in humans and various animals. The conchae are shaped like an elongated seashell, which gave them their name (Latin ''concha'' from Greek ''κόγχη''). A concha is any of the scrolled spongy bones of the nasal passages in vertebrates.''Anatomy of the Human Body''
Gray, Henry (1918) The Nasal Cavity.
In humans, the conchae divide the nasal airway into four groove-like air passages, and are responsible for forcing inhaled air to flow in a steady, regular pattern around the largest possible surface area of

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Nasal Fossa
The nasal cavity is a large, air-filled space above and behind the nose in the middle of the face. The nasal septum divides the cavity into two cavities, also known as fossae. Each cavity is the continuation of one of the two nostrils. The nasal cavity is the uppermost part of the respiratory system and provides the nasal passage for inhaled air from the nostrils to the nasopharynx and rest of the respiratory tract. The paranasal sinuses surround and drain into the nasal cavity. Structure The term "nasal cavity" can refer to each of the two cavities of the nose, or to the two sides combined. The lateral wall of each nasal cavity mainly consists of the maxilla. However, there is a deficiency that is compensated for by the perpendicular plate of the palatine bone, the medial pterygoid plate, the labyrinth of ethmoid and the inferior concha. The paranasal sinuses are connected to the nasal cavity through small orifices called ostia. Most of these ostia communicate with the ...
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Nervous System
In biology, the nervous system is the highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. The nervous system detects environmental changes that impact the body, then works in tandem with the endocrine system to respond to such events. Nervous tissue first arose in wormlike organisms about 550 to 600 million years ago. In vertebrates it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal cord. The PNS consists mainly of nerves, which are enclosed bundles of the long fibers or axons, that connect the CNS to every other part of the body. Nerves that transmit signals from the brain are called motor nerves or '' efferent'' nerves, while those nerves that transmit information from the body to the CNS are called sensory nerves or '' afferent''. Spinal nerves are mixed nerves that serv ...
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Ultradian
In chronobiology, an ultradian rhythm is a recurrent period or cycle repeated throughout a 24-hour day. In contrast, circadian rhythms complete one cycle daily, while infradian rhythms such as the human menstrual cycle have periods longer than a day. The ''Oxford English Dictionary's'' definition of ''Ultradian'' specifies that it refers to cycles with a period shorter than a day but longer than an hour. The descriptive term ultradian is used in sleep research in reference to the 90–120 minute cycling of the sleep stages during human sleep. There is a circasemidian rhythm in body temperature and cognitive function which is technically ultradian. However, this appears to be the first harmonic of the circadian rhythm of each and not an endogenous rhythm with its own rhythm generator. Other ultradian rhythms include blood circulation, blinking, pulse, hormonal secretions such as growth hormone, heart rate, thermoregulation, micturition, bowel activity, nostril dilation, ap ...
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Brain Hemisphere
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 p ...
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Penguin Group
Penguin Group is a British trade book publisher and part of Penguin Random House, which is owned by the German media conglomerate Bertelsmann. The new company was created by a merger that was finalised on 1 July 2013, with Bertelsmann initially owning 53% of the joint venture, and Pearson PLC initially owning the remaining 47%. Since 18 December 2019, Penguin Random House has been wholly owned by Bertelsmann. Penguin Books has its registered office in City of Westminster, London.Maps
." City of Westminster. Retrieved 28 August 2009.
Its British division is Penguin Books Ltd. Other separate divisions are located in the

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Pathology
Pathology is the study of the causes and effects of disease or injury. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in the context of modern medical treatment, the term is often used in a narrower fashion to refer to processes and tests that fall within the contemporary medical field of "general pathology", an area which includes a number of distinct but inter-related medical specialties that diagnose disease, mostly through analysis of tissue, cell, and body fluid samples. Idiomatically, "a pathology" may also refer to the predicted or actual progression of particular diseases (as in the statement "the many different forms of cancer have diverse pathologies", in which case a more proper choice of word would be " pathophysiologies"), and the affix ''pathy'' is sometimes used to indicate a state of disease in cases of both physical ailment (as in cardi ...
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Australian Broadcasting Corporation
The Australian Broadcasting Corporation (ABC) is the national broadcaster of Australia. It is principally funded by direct grants from the Australian Government and is administered by a government-appointed board. The ABC is a publicly-owned body that is politically independent and fully accountable, with its charter enshrined in legislation, the ''Australian Broadcasting Corporation Act 1983''. ABC Commercial, a profit-making division of the corporation, also helps to generate funding for content provision. The ABC was established as the Australian Broadcasting Commission on 1 July 1932 by an act of federal parliament. It effectively replaced the Australian Broadcasting Company, a private company established in 1924 to provide programming for A-class radio stations. The ABC was given statutory powers that reinforced its independence from the government and enhanced its news-gathering role. Modelled after the British Broadcasting Corporation (BBC), which is funded by a tel ...
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Nature (journal)
''Nature'' is a British weekly scientific journal founded and based in London, England. As a multidisciplinary publication, ''Nature'' features peer-reviewed research from a variety of academic disciplines, mainly in science and technology. It has core editorial offices across the United States, continental Europe, and Asia under the international scientific publishing company Springer Nature. ''Nature'' was one of the world's most cited scientific journals by the Science Edition of the 2019 '' Journal Citation Reports'' (with an ascribed impact factor of 42.778), making it one of the world's most-read and most prestigious academic journals. , it claimed an online readership of about three million unique readers per month. Founded in autumn 1869, ''Nature'' was first circulated by Norman Lockyer and Alexander Macmillan as a public forum for scientific innovations. The mid-20th century facilitated an editorial expansion for the journal; ''Nature'' redoubled its efforts in ...
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Nose-blowing
Nose-blowing is the act of expelling nasal mucus by exhaling forcefully through the nose. This is usually done into a facial tissue or handkerchief, facial tissues being more hygienic as they are disposed of after each use while handkerchiefs are softer and more environmentally-friendly. Nose-blowing may be used to alleviate nasal congestion or rhinorrhea (runny nose) resulting from colds, seasonal allergies, or to expel nasal irritants. Technique The tissue or handkerchief is held gently against the nose. Prior to nose blowing, a deep inhale through the mouth or nose provides the air required to eject the nasal mucus. Exhaling hard through both nostrils at once (or, if only one nostril is congested, just the affected nostril) will effectively eject the mucus. The process may need to be repeated several times to sufficiently clear the entire nose. Health effects While nose-blowing helps to alleviate symptoms of the common cold and hayfever, when it is done excessively ...
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Deviated Septum
Nasal septum deviation is a physical disorder of the nose, involving a displacement of the nasal septum. Some displacement is common, affecting 80% of people, mostly without their knowledge. Signs and symptoms The nasal septum is the bone and cartilage in the nose that separates the nasal cavity into the two nostrils. The cartilage is called the quadrangular cartilage and the bones comprising the septum include the maxillary crest, vomer and the perpendicular plate of the ethmoid. Normally, the septum lies centrally, and thus the nasal passages are symmetrical. A deviated septum is an abnormal condition in which the top of the cartilaginous ridge leans to the left or the right, causing obstruction of the affected nasal passage. It is common for nasal septa to depart from the exact centerline; the septum is only considered deviated if the shift is substantial or causes problems. By itself, a deviated septum can go undetected for years and thus be without any need for corre ...
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