respiratory physiology Flashcards
What is the primary function of the respiratory system?
The primary function of the respiratory system is to bring oxygen into the body and remove carbon dioxide.
Explain Dalton’s Law and its relevance to respiration.
Dalton’s Law states that the total pressure of a gas mixture is the sum of the partial pressures of each individual gas. In respiration, gases move down their own partial pressure gradients, from an area of high partial pressure to an area of low partial pressure
Explain Boyle’s Law and how it applies to breathing.
Boyle’s Law states that there is an inverse relationship between the volume of a container and the pressure inside it. We breathe by changing the volume of our thoracic cavity; increasing volume decreases internal pressure (inhalation), and decreasing volume increases internal pressure (exhalation).
Explain Henry’s Law and its role in gas exchange.
Henry’s Law states that each gas moves down its own pressure gradient through a fluid. This law helps explain how oxygen and carbon dioxide dissolve in and move across the fluid lining of the alveoli and the capillary membranes during gas exchange.
What muscles are primarily involved in the breathing mechanism?
The diaphragm and intercostal muscles are crucial for inhalation and exhalation, changing the volume of the thoracic cavity.
What is the role of the pleural cavity and pleura in breathing?
The pleural cavity, enclosed by the visceral and parietal pleura, contains a small amount of fluid that creates surface tension, causing the lungs to stick to the thoracic wall. This adherence allows the lungs to move with the changes in the volume of the thoracic cavity during breathing.
Describe the process of gas exchange in the lungs.
Gas exchange occurs across the respiratory membrane in the alveoli. Oxygen moves from the alveoli (high partial pressure) into the bloodstream (low partial pressure), while carbon dioxide moves from the bloodstream (high partial pressure) into the alveoli (low partial pressure).
What is surfactant, where is it produced, and what is its function?
Surfactant is a substance secreted by Type II alveolar cells. Its function is to reduce the surface tension of the water lining the alveoli, preventing them from collapsing, especially during exhalation.
Differentiate between ventilation and respiration.
Ventilation is the physical movement of air into and out of the lungs. Respiration is the process of gas exchange (oxygen and carbon dioxide) across membranes, such as in the alveoli and tissues.
What is the role of elastic tissue in the airways, and what happens when it’s damaged?
Elastic tissue in the airways helps keep them open. Damage to this tissue, for example in conditions like emphysema, can cause the airways to collapse during exhalation, leading to breathing difficulties.
What are the basic structural components of the lungs
composed of thin epithelial tissue and areolar connective tissue, with alveoli being the smallest structural units.
Describe the layers of the pleura and the space between them.
visceral pleura is the inner layer directly covering the lungs. The parietal pleura is the outer layer connected to the chest wall. The pleural cavity is the potential space between these two layers.
What is the function of pleural fluid?
Pleural fluid is a serous fluid within the pleural cavity that reduces friction between the visceral and parietal pleura during breathing.
What condition can result from insufficient pleural fluid?
Pleurisy is a condition resulting from inflammation due to insufficient pleural fluid, causing increased friction.
Define Intrapulmonary Pressure.
Intrapulmonary pressure is the pressure within the alveoli. It is approximately 760 mm Hg at rest, equal to atmospheric pressure.
Define Intrapleural Pressure.
Intrapleural pressure is the pressure within the pleural cavity. It is normally negative relative to atmospheric pressure (about 756 mm Hg or -4 mm Hg) and always negative relative to intrapulmonary pressure.
Define Atmospheric Pressure.
Atmospheric pressure is the pressure outside the body, approximately 760 mm Hg at sea level.
What factors contribute to the negative intrapleural pressure?
The negative intrapleural pressure is caused by the elastic recoil of the lungs (tendency to collapse), the surface tension in the alveoli (also promoting collapse), and the elastic recoil of the chest wall (tendency to expand outwards).
How do lymphatic vessels contribute to maintaining proper intrapleural pressure?
Lymphatic vessels drain excess fluid from the pleural cavity, helping to maintain the appropriate volume and pressure within the space.
Define Transpulmonary Pressure and its significance.
Transpulmonary pressure is the difference between intrapulmonary pressure and intrapleural pressure. A positive transpulmonary pressure keeps the lungs inflated.
Define Transthoracic Pressure.
Transthoracic pressure is the difference between intrapleural pressure and atmospheric pressure. It reflects the forces acting on the chest wall.
Define Transrespiratory Pressure.
Transrespiratory pressure is the difference between intrapulmonary pressure and atmospheric pressure. It represents the overall pressure gradient across the respiratory system and is zero at rest
