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Starling Resistor
The Starling resistor was invented by English physiologist Ernest Starling and used in an isolated-heart preparation during work which would later lead to the " Frank–Starling law of the heart". The device consisted of an elastic fluid-filled collapsible-tube mounted inside a chamber filled with air. The static pressure inside the chamber was used to control the degree of collapse of the tube, so providing a variable resistor. This resistance was used to simulate TPR, or total peripheral (vascular) resistance. Starling resistors have been used both as an instrument in the study of interesting physiological phenomena (e.g. pharyngeal collapse during obstructed breathing or OSA) and as a rich source of physical phenomena in their own right. Two non-linear behaviours are characteristic: 1) the “waterfall effect” wherein, subsequent to collapse, the flow through the tube becomes independent of the downstream pressure and 2) self-excited oscillations. Expiratory flow-limitat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
England
England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe by the North Sea to the east and the English Channel to the south. The country covers five-eighths of the island of Great Britain, which lies in the North Atlantic, and includes over 100 smaller islands, such as the Isles of Scilly and the Isle of Wight. The area now called England was first inhabited by modern humans during the Upper Paleolithic period, but takes its name from the Angles, a Germanic tribe deriving its name from the Anglia peninsula, who settled during the 5th and 6th centuries. England became a unified state in the 10th century and has had a significant cultural and legal impact on the wider world since the Age of Discovery, which began during the 15th century. The English language, the Anglican Church, and Engli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physiologist
Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical and physical functions in a living system. According to the classes of organisms, the field can be divided into medical physiology, animal physiology, plant physiology, cell physiology, and comparative physiology. Central to physiological functioning are biophysical and biochemical processes, homeostatic control mechanisms, and communication between cells. ''Physiological state'' is the condition of normal function. In contrast, ''pathological state'' refers to abnormal conditions, including human diseases. The Nobel Prize in Physiology or Medicine is awarded by the Royal Swedish Academy of Sciences for exceptional scientific achievements in physiology related to the field of medicine. Foundations Cells Although there are difference ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernest Starling
Ernest Henry Starling (17 April 1866 – 2 May 1927) was a British physiologist who contributed many fundamental ideas to this subject. These ideas were important parts of the British contribution to physiology, which at that time led the world. He made at least four significant contributions: 1. In the capillary, water is forced out through the pores in the wall by hydrostatic pressure and driven in by the osmotic pressure of plasma proteins (or oncotic pressure). These opposing forces approximately balance; which is known as Starling's Principle. 2. The discovery of the hormone secretinwith his brother-in-law William Baylissand the introduction of the word hormone. 3. The analysis of the heart's activity as a pump, which is known as the Frank–Starling law. 4. Several fundamental observations on the action of the kidneys. These include evidence for the existence of vasopressin, the anti-diuretic hormone. He also wrote the leading textbook of physiology in English, which ran t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sleep Apnea
Sleep apnea, also spelled sleep apnoea, is a sleep disorder in which pauses in breathing or periods of shallow breathing during sleep occur more often than normal. Each pause can last for a few seconds to a few minutes and they happen many times a night. In the most common form, this follows loud snoring. There may be a choking or snorting sound as breathing resumes. Because the disorder disrupts normal sleep, those affected may experience sleepiness or feel tired during the day. In children, it may cause hyperactivity or problems in school. Sleep apnea may be either obstructive sleep apnea (OSA), in which breathing is interrupted by a blockage of air flow, central sleep apnea (CSA), in which regular unconscious breath simply stops, or a combination of the two. OSA is the most common form. OSA has four key contributors; these include a narrow, crowded, or collapsible upper airway, an ineffective pharyngeal dilator muscle function during sleep, airway narrowing during sleep and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chronic Obstructive Pulmonary Disease
Chronic obstructive pulmonary disease (COPD) is a type of progressive lung disease characterized by long-term respiratory symptoms and airflow limitation. The main symptoms include shortness of breath and a cough, which may or may not produce mucus. COPD progressively worsens, with everyday activities such as walking or dressing becoming difficult. While COPD is incurable, it is preventable and treatable. The two most common conditions of COPD are emphysema and chronic bronchitis and they have been the two classic COPD phenotypes. Emphysema is defined as enlarged airspaces ( alveoli) whose walls have broken down resulting in permanent damage to the lung tissue. Chronic bronchitis is defined as a productive cough that is present for at least three months each year for two years. Both of these conditions can exist without airflow limitation when they are not classed as COPD. Emphysema is just one of the structural abnormalities that can limit airflow and can exist without ai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snoring
Snoring is the vibration of respiratory structures and the resulting sound due to obstructed air movement during breathing while sleeping. The sound may be soft or loud and unpleasant. Snoring during sleep may be a sign, or first alarm, of obstructive sleep apnea (OSA). Research suggests that snoring is one of the factors of sleep deprivation. Causes Snoring is the result of the relaxation of the uvula and soft palate. These tissues can relax enough to partially block the airway, resulting in irregular airflow and vibrations. Snoring can be attributed to one or more of the following: * Genetic predisposition, a proportion of which may be mediated through other heritable lifestyle factors such as body mass index, smoking and alcohol consumption. *Throat weakness, causing the throat to close during sleep. * Mispositioned jaw, often caused by tension in the muscles. * Obesity that has caused fat to gather in and around the throat. * Obstruction in the nasal passageway. * Obstruct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
