Alveolar Pressure

	Alveolar Pressure Alveolar pressure (Palv) is the pressure of air inside the lung Pulmonary alveolus, alveoli. When the glottis is opened and no air is flowing into or out of the lungs, alveolar pressure is equal to the atmospheric pressure, that is, zero cmH2O, cmH2O.Guyton and Hall Textbook of Medical Physiology, 12th edition. 23 May 2016 Significance During inhalation, the increased volume of Pulmonary alveolus, alveoli as a result of lung expansion decreases the intra-alveolar pressure to a value below atmospheric pressure about -1 cmH2O. This slight negative pressure is enough to move 500 ml of air into the lungs in the 2 seconds required for inspiration. At the end of inspiration, the alveolar pressure returns to atmospheric pressure (zero cmH2O). During exhalation, the opposite change occurs. The lung alveoli collapse before air is expelled from them. The alveolar pressure rises to about +1 cmH2O. This forces the 500 ml of inspired air out of the lung during the 2–3 seconds of expiratio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Lung The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of the heart. Their function in the respiratory system is to extract oxygen from the air and transfer it into the bloodstream, and to release carbon dioxide from the bloodstream into the atmosphere, in a process of gas exchange. Respiration is driven by different muscular systems in different species. Mammals, reptiles and birds use their different muscles to support and foster breathing. In earlier tetrapods, air was driven into the lungs by the pharyngeal muscles via buccal pumping, a mechanism still seen in amphibians. In humans, the main muscle of respiration that drives breathing is the diaphragm. The lungs also provide airflow that makes vocal sounds including human speech possible. Humans have two lungs, one on the left and on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Pulmonary Alveolus A pulmonary alveolus (plural: alveoli, from Latin ''alveolus'', "little cavity"), also known as an air sac or air space, is one of millions of hollow, distensible cup-shaped cavities in the lungs where oxygen is exchanged for carbon dioxide. Alveoli make up the functional tissue of the mammalian lungs known as the lung parenchyma, which takes up 90 percent of the total lung volume. Alveoli are first located in the respiratory bronchioles that mark the beginning of the respiratory zone. They are located sparsely in these bronchioles, line the walls of the alveolar ducts, and are more numerous in the blind-ended alveolar sacs. The acini are the basic units of respiration, with gas exchange taking place in all the alveoli present. The alveolar membrane is the gas exchange surface, surrounded by a network of capillaries. Across the membrane oxygen is diffused into the capillaries and carbon dioxide released from the capillaries into the alveoli to be breathed out. Alveoli are pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Glottis The glottis is the opening between the vocal folds (the rima glottidis). The glottis is crucial in producing vowels and voiced consonants. Etymology From Ancient Greek ''γλωττίς'' (glōttís), derived from ''γλῶττα'' (glôtta), variant of ''γλῶσσα'' (glôssa, "tongue"). Function Phonation As the vocal folds vibrate, the resulting vibration produces a "buzzing" quality to the speech, called voice or voicing or pronunciation. Sound production that involves moving the vocal folds close together is called ''glottal''. English has a voiceless glottal transition spelled "h". This sound is produced by keeping the vocal folds spread somewhat, resulting in non-turbulent airflow through the glottis. In many accents of English the glottal stop (made by pressing the folds together) is used as a variant allophone of the phoneme (and in some dialects, occasionally of and ); in some languages, this sound is a phoneme of its own. Skilled players of the Australian di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	CmH2O A centimetre or millimetre of water (US spelling ''centimeter'' or ''millimeter of water'') are less commonly used measures of pressure Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and e ... derived from pressure head. Centimetre of water A ''centimetre of water'' (US spelling ''centimeter of water'')NOTE: A centimetre of water is abbreviated as ''cm'' or ''cm H2O''. is a unit of pressure. It may be defined as the pressure exerted by a column of water of 1 centimetre, cm in height at 4 celsius, °C (temperature of maximum density) at the standard acceleration of gravity, so that = × × 1 cm = ≈ , but conventionally a nominal maximum water density of is used, giving . The centimetre of water unit is frequently used to measure the central venous pressure, the intracranial pres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Inhalation Inhalation (or Inspiration) happens when air or other gases enter the lungs. Inhalation of air Inhalation of air, as part of the cycle of breathing, is a vital process for all human life. The process is autonomic (though there are exceptions in some disease states) and does not need conscious control or effort. However, breathing can be consciously controlled or interrupted (within limits). Breathing allows oxygen (which humans and a lot of other species need for survival) to enter the lungs, from where it can be absorbed into the bloodstream. Other substances – accidental Examples of accidental inhalation includes inhalation of water (e.g. in drowning), smoke, food, vomitus and less common foreign substances (e.g. tooth fragments, coins, batteries, small toy parts, needles). Other substances – deliberate Recreational use Legal – helium, nitrous oxide ("laughing gas") Illegal – various gaseous, vaporised or aerosolized recreational drugs Medical use Diag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Exhalation Exhalation (or expiration) is the flow of the breath out of an organism. In animals, it is the movement of air from the lungs out of the airways, to the external environment during breathing. This happens due to elastic properties of the lungs, as well as the internal intercostal muscles which lower the rib cage and decrease thoracic volume. As the thoracic diaphragm relaxes during exhalation it causes the tissue it has depressed to rise superiorly and put pressure on the lungs to expel the air. During forced exhalation, as when blowing out a candle, expiratory muscles including the abdominal muscles and internal intercostal muscles generate abdominal and thoracic pressure, which forces air out of the lungs. Exhaled air is 4% carbon dioxide, a waste product of cellular respiration during the production of energy, which is stored as ATP. Exhalation has a complementary relationship to inhalation which together make up the respiratory cycle of a breath. Exhalation and gas e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Respiratory Therapy A respiratory therapist is a specialized healthcare professional, healthcare practitioner trained in Intensive care medicine, critical care and cardio-pulmonary medicine in order to work therapeutically with people who have acute critical conditions, Cardiovascular disease, cardiac and Respiratory disease, pulmonary disease. Respiratory therapists graduate from a college or university with a degree in respiratory therapy and have passed a national board certifying examination. The NBRC (National Board for Respiratory Care) is responsible for credentialing as a CRT (Certified Respiratory Therapist, certified respiratory therapist), or RRT (Registered Respiratory Therapist, registered respiratory therapist), The specialty certifications of respiratory therapy include: CPFT and RPFT (Certified or Registered Pulmonary Function Technologist), ACCS (Adult Critical Care Specialist), NPS (Neonatal/Pediatric Specialist), and SDS (Sleep disorder specialist, Sleep Disorder Specialist). Re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Pulmonology Pulmonology (, , from Latin ''pulmō, -ōnis'' "lung" and the Greek suffix "study of"), pneumology (, built on Greek πνεύμων "lung") or pneumonology () is a medical specialty that deals with diseases involving the respiratory tract.ACP: Pulmonology: Internal Medicine Subspecialty . Acponline.org. Retrieved on 2011-09-30. It is also known as respirology, respiratory medicine, or chest medicine in some countries and areas. Pulmonology is considered a branch of internal medicine, and is related to intensive care medicine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]