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Pores Of Kohn
The pores of Kohn (also known as interalveolar connections or alveolar pores) are discrete holes in alveolar wall, walls of adjacent Pulmonary alveolus, alveoli. Cuboidal type II alveolar cells, which produce Pulmonary surfactant, surfactant, usually form part of aperture. Etymology The pores of Kohn take their name from the German physician and pathologist Hans Nathan Kohn (1866–1935) who first described them in 1893. Development They are absent in human newborns. They develop at 3–4 years of age along with canals of Lambert during the process of thinning of alveolar septa. Function The pores allow the passage of other materials such as fluid and bacteria, which is an important mechanism of spread of infection in lobar pneumonia and spread of fibrin in the Hepatization of lungs , grey hepatisation phase of recovery from the same. They also equalize the pressure in adjacent alveoli and, combined with increased distribution of surfactant, thus play an important role in preventio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alveolar Wall
A pulmonary alveolus (; ), also called an air sac or air space, is one of millions of hollow, distensible cup-shaped cavities in the lungs where pulmonary gas exchange takes place. Oxygen is Molecular diffusion#Biology, exchanged for carbon dioxide at the blood–air barrier between the alveolar air and the Pulmonary circulation, pulmonary capillary. 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 Pulmonary acinus, 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 capillary, capillaries. Oxygen is Diffusion#Dif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulmonary Alveolus
A pulmonary alveolus (; ), also called an air sac or air space, is one of millions of hollow, distensible cup-shaped cavities in the lungs where pulmonary gas exchange takes place. Oxygen is exchanged for carbon dioxide at the blood–air barrier between the alveolar air and the pulmonary capillary. 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. Oxygen is diffused across the membrane into the capillaries and carbon dioxide is released fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulmonary Surfactant
Pulmonary surfactant is a surface-active complex of phospholipids and proteins formed by Type II cells, type II alveolar cells. The proteins and lipids that make up the surfactant have both hydrophilic and hydrophobic regions. By adsorption, adsorbing to the air-water Interface (chemistry), interface of pulmonary alveolus, alveoli, with hydrophilic head groups in the water and the hydrophobic tails facing towards the air, the main lipid component of the surfactant, dipalmitoylphosphatidylcholine (DPPC), reduces surface tension. As a medication, Pulmonary surfactant (medication), pulmonary surfactant is on the WHO Model List of Essential Medicines, the most important medications needed in a basic health system. Function * To increase pulmonary compliance. * To prevent atelectasis (collapse of the alveoli or atriums) at the end of expiration. * To facilitate recruitment of collapsed airways. Alveoli can be compared to gas in water, as the alveoli are wet and surround a central a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canals Of Lambert
Collateral ventilation is a back-up system of alveolar ventilation that can bypass the normal route of airflow when airways are restricted or obstructed. The pathways involved include those between adjacent alveoli (pores of Kohn), between bronchioles and alveoli (canals of Lambert), and those between bronchioles (channels of Martin). Collateral ventilation also serves to modulate imbalances in ventilation and perfusion a feature of many diseases. The pathways are altered in lung diseases particularly asthma, and emphysema. A similar functional pattern of collateralisation is seen in the circulatory system of the heart. Interlobar collateral ventilation has also been noted and is a major unwanted factor in the consideration of lung volume reduction surgery and some lung volume reduction procedures. Pathways In normal respiratory conditions, airflow is through the pathway of least resistance offered by the bronchial tree, to the alveoli and back to the bronchi and trachea. In t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lobar Pneumonia
Lobar pneumonia is a form of pneumonia characterized by inflammatory exudate within the intra-alveolar space resulting in consolidation that affects a large and continuous area of the lobe of a lung. It is one of three anatomic classifications of pneumonia (the other being bronchopneumonia and atypical pneumonia). In children round pneumonia develops instead because the pores of Kohn which allow the lobar spread of infection are underdeveloped. Pathophysiology The invading organism starts multiplying, thereby releasing toxins that cause inflammation and edema of the lung parenchyma. This leads to the accumulation of cellular debris within the lungs. This leads to consolidation or solidification, terms used for macroscopic or radiologic appearance of the lungs affected by pneumonia. Bacterial pneumonia is mainly classified into lobar and diffuse depending on the degree of lung irritation or damage. Stages Lobar pneumonia usually has an acute progression. Classically, the dis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatization Of Lungs
Hepatization of the lungs is an old name for changes to the visual appearance of the lungs so that they resemble the liver. This happens when they are gorged with effuse matter and are no longer pervious to the air. The main cause is lobar pneumonia. Hepatization appears in ultrasounds as consolidations. Red hepatization is when there are red blood cells, neutrophils, and fibrin in the pulmonary alveolus/alveoli. The texture of the lungs changes, and, unlike healthy lungs, they no longer float if placed in a bowl of water. Red hepatization precedes or may be found in combination with gray hepatization, where the red cells have been broken down, leaving a fibrinosuppurative exudate. Yellow hepatization is uncommon due to treatment with antibiotics, but it may occasionally be seen, e.g., during an autopsy An autopsy (also referred to as post-mortem examination, obduction, necropsy, or autopsia cadaverum) is a surgical procedure that consists of a thorough examination ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atelectasis
Atelectasis is the partial collapse or closure of a lung resulting in reduced or absence in gas exchange. It is usually unilateral, affecting part or all of one lung. It is a condition where the Pulmonary alveolus, alveoli are deflated down to little or no volume, as distinct from pulmonary consolidation, in which they are filled with liquid. It is often referred to wikt:Appendix:Glossary#informal, informally as a collapsed lung, although more accurately it usually involves only a partial collapse, and that ambiguous term is also informally used for a fully collapsed lung caused by a pneumothorax. It is a very common finding in chest X-rays and other radiological studies, and may be caused by normal exhalation or by various medical conditions. Although frequently described as a ''collapse of lung tissue'', atelectasis is not synonymous with a pneumothorax, which is a more specific condition that can cause atelectasis. Acute atelectasis may occur as a post-operative complication ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Round Pneumonia
Lobar pneumonia is a form of pneumonia characterized by inflammatory exudate within the intra-alveolar space resulting in consolidation that affects a large and continuous area of the lobe of a lung. It is one of three anatomic classifications of pneumonia (the other being bronchopneumonia and atypical pneumonia). In children round pneumonia develops instead because the pores of Kohn which allow the lobar spread of infection are underdeveloped. Pathophysiology The invading organism starts multiplying, thereby releasing toxins that cause inflammation and edema of the lung parenchyma. This leads to the accumulation of cellular debris within the lungs. This leads to consolidation or solidification, terms used for macroscopic or radiologic appearance of the lungs affected by pneumonia. Bacterial pneumonia is mainly classified into lobar and diffuse depending on the degree of lung irritation or damage. Stages Lobar pneumonia usually has an acute progression. Classically, the dis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lung Anatomy
The lungs are the primary organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, 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 atmosphere 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 musculoskeletal systems to support and foster breathing. In early tetrapods, air was driven into the lungs by the pharyngeal muscles via buccal pumping, a mechanism still seen in amphibians. In humans, the primary muscle that drives breathing is the diaphragm. The lungs also provide airflow that makes vocalisation including speech possible. Humans have two lungs, a right lung and a left lung. They are situated within the thoracic cavity of the chest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holes
A hole is an opening in or through a particular medium, usually a solid body. Holes occur through natural and artificial processes, and may be useful for various purposes, or may represent a problem needing to be addressed in many fields of engineering. Depending on the material and the placement, a hole may be an indentation in a surface (such as a hole in the ground), or may pass completely through that surface (such as a hole created by a hole puncher in a piece of paper). Types Holes can occur for a number of reasons, including natural processes and intentional actions by humans or animals. Holes in the ground that are made intentionally, such as holes made while searching for food, for replanting trees, or postholes made for securing an object, are usually made through the process of digging. Unintentional holes in an object are often a sign of damage. Potholes and sinkholes can damage human settlements. Holes can occur in a wide variety of materials, and at a wide range ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
