logo

PreLab Video Model Lung

Pearson
46 views
Was this helpful ?
0
Operating the model lung. Pulmonary ventilation is the act of breathing. It involves two phases: inspiration, when air moves into the lungs, and expiration, when air exits the lungs. This video will demonstrate how to use a plastic bell jar to model pulmonary ventilation and relate Boyle's law to inspiration and expiration. We will use a model lung to simulate pulmonary ventilation. The bell jar represents the thoracic cavity. The jar has a rubber membrane that acts as the diaphragm. It is equipped with two balloons representing the lungs, and a Y-shaped tube representing the trachea and main bronchi. Boyle's law states that at a constant temperature, pressure and volume are inversely proportional to each other. Thus, if the volume of the container decreases, the pressure of the gas inside the container increases. Likewise, an increase in the container volume will result in a decrease in the pressure inside the container. When you pull down on the diaphragm, moving it from a superior position to a more inferior position, the volume inside the bell jar increases. This action simulates the contraction of the diaphragm muscle, which increases the volume of the thoracic cavity. What happened to the pressure in the thoracic cavity when the diaphragm was pulled downward: pressure increased because volume increased, pressure decreased because volume increased, pressure increased because volume decreased, pressure decreased because volume decreased. Recall that pressure is inversely proportional to volume. Pulling the diaphragm down increases the volume in the thoracic cavity. This results in a decrease in pressure. When exploring pulmonary ventilation, it is important to remember that volume changes lead to pressure changes, which lead to the flow of gases to equalize the pressure. When the volume of the thoracic cavity increases, the pressure inside the thoracic cavity decreases. The pressure inside the thoracic cavity is now lower than the pressure outside the thoracic cavity, creating a pressure gradient. Gases flow down their pressure gradients, from higher pressure to lower pressure. In the case of our model lung, air flows into the balloons, simulating inspiration. In the body, air flows into the lungs. What do you predict will happen when the diaphragm is pushed upward? The balloons will inflate, simulating inspiration. The balloons will deflate, simulating inspiration. The balloons will inflate, simulating expiration. The balloons will deflate, simulating expiration. Pushing the diaphragm up reduces the volume and increases the pressure in the thoracic cavity. The air flows down its pressure gradient and out of the balloons. This simulates relaxation of the diaphragm, which results in an increase in pressure in the thoracic cavity. Air will exit the balloons, simulating expiration.
Operating the model lung. Pulmonary ventilation is the act of breathing. It involves two phases: inspiration, when air moves into the lungs, and expiration, when air exits the lungs. This video will demonstrate how to use a plastic bell jar to model pulmonary ventilation and relate Boyle's law to inspiration and expiration. We will use a model lung to simulate pulmonary ventilation. The bell jar represents the thoracic cavity. The jar has a rubber membrane that acts as the diaphragm. It is equipped with two balloons representing the lungs, and a Y-shaped tube representing the trachea and main bronchi. Boyle's law states that at a constant temperature, pressure and volume are inversely proportional to each other. Thus, if the volume of the container decreases, the pressure of the gas inside the container increases. Likewise, an increase in the container volume will result in a decrease in the pressure inside the container. When you pull down on the diaphragm, moving it from a superior position to a more inferior position, the volume inside the bell jar increases. This action simulates the contraction of the diaphragm muscle, which increases the volume of the thoracic cavity. What happened to the pressure in the thoracic cavity when the diaphragm was pulled downward: pressure increased because volume increased, pressure decreased because volume increased, pressure increased because volume decreased, pressure decreased because volume decreased. Recall that pressure is inversely proportional to volume. Pulling the diaphragm down increases the volume in the thoracic cavity. This results in a decrease in pressure. When exploring pulmonary ventilation, it is important to remember that volume changes lead to pressure changes, which lead to the flow of gases to equalize the pressure. When the volume of the thoracic cavity increases, the pressure inside the thoracic cavity decreases. The pressure inside the thoracic cavity is now lower than the pressure outside the thoracic cavity, creating a pressure gradient. Gases flow down their pressure gradients, from higher pressure to lower pressure. In the case of our model lung, air flows into the balloons, simulating inspiration. In the body, air flows into the lungs. What do you predict will happen when the diaphragm is pushed upward? The balloons will inflate, simulating inspiration. The balloons will deflate, simulating inspiration. The balloons will inflate, simulating expiration. The balloons will deflate, simulating expiration. Pushing the diaphragm up reduces the volume and increases the pressure in the thoracic cavity. The air flows down its pressure gradient and out of the balloons. This simulates relaxation of the diaphragm, which results in an increase in pressure in the thoracic cavity. Air will exit the balloons, simulating expiration.