Turbulent flow b has disorganized layers and high resistance. Privacy Policy. Skip to main content. Respiratory System. Search for:. Factors Affecting Pulmonary Ventilation. Factors Affecting Pulmonary Ventilation: Surface Tension of Alveolar Fluid The surface tension of alveolar fluid is regulated by pulmonary surfactant, allowing efficient respiration.
Learning Objectives Describe surfactant and its role in alveolar fluid surface tension. Key Takeaways Key Points Type II avleolar epithelial cells secrete pulmonary surfactant to lower the surface tension of water, which helps prevent airway collapse.
Reinflation of the alveoli following exhalation is made easier by pulmonary surfactant. The surfactant reduces surface tension within all alveoli through hydrophilic and hydrophobic forces. Insufficient pulmonary surfactant in the alveoli can contribute to atelectasis collapse of part or all of the lung. Key Terms atelectasis : The collapse of a part of or the whole lung caused by inner factors, rather than a pneumothorax.
Surface tension : The inward force created by films of molecules that can reduce the area of a surface. Examples Elective cesarean sections are becoming more common. Factors Affecting Pulmonary Ventilation: Compliance of the Lungs Lung compliance refers to the magnitude of change in lung volume as a result of the change in pulmonary pressure.
Learning Objectives Evaluate the factors involved in lung compliance. Key Takeaways Key Points A low lung compliance would mean that the lungs would need a greater-than-average change in intrapleural pressure to change the volume of the lungs. A high lung compliance would indicate that little pressure difference in intrapleural pressure is needed to change the volume of the lungs. Persons with low lung compliance due to obstructive lung diseases tend to take rapid shallow breaths and sit hunched over to make exhalation less difficult.
Persons with high lung compliance due to restrictive lung diseases tend to have difficulty expanding and deflating the lungs. Two factors determine lung compliance: elasticity of the lung tissue and surface tensions at air water interfaces. Two factors determine lung compliance — elasticity of the lung tissue and surface tensions at air water interfaces. Key Terms Lung compliance : The ability of the lungs and pleural cavity to change in volume based on changes in pressure.
Examples Low lung compliance can be the result of interstitial lung diseases resulting from the inhalation of particulate substances such as asbestos asbestosis and silicon silicosis. Factors Affecting Pulmonary Ventilation: Airway Resistance Airway resistance refers to resistance in the respiratory tract to airflow.
Learning Objectives Describe airway resistance and how it affects pulmonary ventilation. Key Takeaways Key Points Airway resistance is a concept in respiratory physiology that describes the resistance of the respiratory tract to airflow during inspiration and expiration.
Airway resistance can be indirectly measured with body plethysmography. Diseases affecting the respiratory tract can increase airway resistance. Laminar flow is orderly and has low resistance while turbulent flow is disorganized and has high resistance. Key Terms Airway resistance : Airway Resistance is a concept in respiratory physiology that describes the resistance of the respiratory tract to airflow during inspiration and expiration. Turbulent flow : Air with disorganized layers that has higher resistance.
It is often located in areas where the airways branch or diverge. Examples Airway resistance can change over time, especially during an asthma attack when the airways constricts causing an increase in airway resistance. Scuba diving and dysbarism. Philadelphia, PA: Elsevier; chap Hallifax R, Rahman NM. Murray and Nadel's Textbook of Respiratory Medicine. Raja AS. Thoracic trauma. Editorial team. Collapsed lung pneumothorax. The medical name of this condition is pneumothorax.
Tall, thin people and smokers are more at risk for a collapsed lung. Lung diseases can also increase the chance of getting a collapsed lung. Common symptoms of a collapsed lung include: Sharp chest or shoulder pain, made worse by a deep breath or a cough Shortness of breath Nasal flaring from shortness of breath A larger pneumothorax causes more severe symptoms, including: Bluish color of the skin due to lack of oxygen Chest tightness Lightheadedness and near fainting Easy fatigue Abnormal breathing patterns or increased effort of breathing Rapid heart rate Shock and collapse.
Exams and Tests. Tests that may be ordered include: Chest x-ray Arterial blood gases and other blood tests CT scan if other injuries or conditions are suspected Electrocardiogram ECG. Some people with a collapsed lung need extra oxygen. Outlook Prognosis. If you have a collapsed lung, you are more likely to have another one in the future if you: Are tall and thin Continue to smoke Have had two collapsed lung episodes in the past How well you do after having a collapsed lung depends on what caused it.
Possible Complications. The respiratory system is situated in the thorax, and is responsible for gaseous exchange between the circulatory system and the outside world. Air is taken in via the upper airways the nasal cavity, pharynx and larynx through the lower airways trachea, primary bronchi and bronchial tree and into the small bronchioles and alveoli within the lung tissue.
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