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Introduction to Anatomy and Physiology
Published in Reginald L. Campbell, Roland E. Langford, Terry L. McArthur, Fundamentals of Hazardous Materials Incidents, 2020
Reginald L. Campbell, Roland E. Langford, Terry L. McArthur
The trachea branches into two major passages called bronchi (singular: bronchus), one going to each lung. These branch in turn into ever smaller passages called bronchioles. All these contain cartilage to prevent collapse. The very smallest bronchioles, however, do not have cartilage rings and simply end in sacs called atria (singular: atrium), each of which contains a number of chambers called alveoli (singular: alveolus). Alveoli are shown in Figure 2-1. It is at the alveoli that the exchange of oxygen to the blood’s hemoglobin and carbon dioxide from the blood takes place. The alveoli on the end of the bronchiole appear like bunches of grapes on a vine. The cells of the alveoli are very sensitive to many chemicals, and the blood lies only one cell thickness away so that transfer of these gases and other substances may occur.
Asbestos Identification and Abatement
Published in Benjamin Alter, Environmental Consulting Fundamentals, 2019
There are three known asbestos-related diseases: asbestosis, lung cancer, and mesothelioma. Asbestosis is a scarring (fibrosis) of the lung that impairs the elasticity of the lung tissue and restricts breathing. Asbestosis has a latency period of 10 to 30 years and generally is associated with a long, heavy exposure to airborne asbestos fibers.Lung cancer is a malignant tumor of the bronchi covering. Although there are many causes of lung cancer, there is a clear increase in risk among people who worked with asbestos. There is no threshold or level of exposure below which the risk of lung cancer is not increased. The typical latency period for lung cancer resulting from asbestos exposure is 20 to 30 years.Mesothelioma is a cancer of the mesothelium—the lining of the chest or the lining of the abdominal wall. It is the only known type of cancer directly attributed to asbestos exposure. By the time it is diagnosed, it is almost always fatal. There is no exposure threshold for mesothelioma, and the disease may not manifest itself until up to 40 years after the time of exposure to asbestos.
Critical Assessment of Epidemiologic Studies of Environmental Factors in Asthma
Published in John R. Goldsmith, Environmental Epidemiology: Epidemiological Investigation of Community Environmental Health Problems, 2019
Inge F. Goldstein, Diana Hartel
The American Thoracic Society has defined asthma as “a disease characterized by an increased responsiveness of the trachea and bronchi to various stimuli and manifested by a widespread narrowing of the airways that changes in severity either spontaneously or as a result of therapy.”1-2 Asthma is a complex heterogeneous disease, the biological mechanisms of which are as yet unknown. The illness is chronic with episodic manifestations of symptoms, usually wheezing, difficulty in breathing, fatigue, cough, and tightness in the chest. Persons with asthma constitute approximately 2 to 3% of the general population in the U.S.2 3 with 9 to 10 million affected people which, according to a 1975 study, incurred an estimated $629 million in direct medical costs.4 While mortality from asthma is infrequent, its chronicity and severity make it a major public health problem.
Computational modelling of airflow in distal airways using hybrid lung model
Published in Mathematical and Computer Modelling of Dynamical Systems, 2023
Olusegun J. Ilegbusi, Adnan Islam, Anand P. Santhanam
Finally, we validated the capacity of the CFD model to predict pressure drop in the airways by comparing our predicted results with pressure drop data obtained from an experimental measurement on a simplified pig lung airway [37]. The study measured the pressure drop between the trachea and selected mid-bronchus utilizing differential pressure transducer. The simplified pig airway and locations of pressure probes are illustrated in Figure 5(a). We performed CFD analysis on this simplified geometry with the same solver and mesh tolerances used in our study but matched the boundary conditions with the experiment. Figure 5b shows the predicted and experimental pressure drops presented as paired points for the three different flowrates considered. Both sets of results exhibit nonlinear increase in pressure drop with increasing flow rate due to greater energy loss at the bifurcations. The predictions are generally in good agreement with the experimental data. The slight increase in discrepancy between the two sets of results at higher flowrates may be attributed to the increase in uncertainty of the measurement.
GBDTMO: as new option for early-stage breast cancer detection and classification using machine learning
Published in Automatika, 2023
Vibith A. S., Jobin Christ M C
Breast cancer is a crippling illness that is becoming more common among women, but it can also strike men. Breast cancer can adversely harm one’s health and ultimately cause death if it is not detected in time or during the early stages of tumour formation. For effective treatment, the early stage diagnosis of tumour development is essential. Although the disease has some symptoms that can aid in the diagnosis, the majority of the symptoms are universal to many other conditions, making the tumour’s progression undetectable. The biologists had just a few traditional techniques for microscopic illness diagnostics, but these techniques could not correctly identify the tumour responsible for the breast cancer. Cancer is now one of the leading causes of morbidity and mortality all over the world. Cancer has resulted in the deaths of approximately 14.5 million people, with the number expected to rise to more than 28 million by 2030. After lung and bronchus cancer, breast cancer is the second leading cause of disease death in women. Furthermore, breast cancer growth accounts for 30% of all new disease cases [1]. From one end of the globe to the other, breast cancer is the most common type of cancer in females, and it is the second most common disease overall, with millions of new cases in 2018. The five-year endurance rate for ladies analysed at earlier stages is more than 90%, and it is around 15% for ladies determined to have the most exceptional stage [2]. Although breast disease can happen in men, it is extremely uncommon.
Deposition of droplets from the trachea or bronchus in the respiratory tract during exhalation: A steady-state numerical investigation
Published in Aerosol Science and Technology, 2020
Yong Guo, Jianjian Wei, Cuiyun Ou, Li Liu, Sasan Sadrizadeh, Tao Jin, Lingling Tang, Yinping Zhang, Yuguo Li
In this study, CFD is used to numerically investigate the motion and deposition of droplets that originate in the trachea or bronchus in the respiratory tract during exhalation. The influence of turbulence and jet flow caused by the complex respiratory tract structure on droplet deposition is studied to obtain a complete droplet deposition curve along the respiratory tract. Although the large droplets produced in the bronchi, trachea, and other structures carry viruses, they are easily deposited in the respiratory tract and rarely escape into the indoor environment. In addition, the virus content of large droplets that originate in the oral cavity is very small and thus plays a negligible role in respiratory disease transmission. This article thus addresses the key question of the critical droplet size via the study of droplet deposition characteristics.