BIOL 221 Lecture Notes - Lecture 7: Internal Intercostal Muscles, Abdominal Cavity, Abdomen
3 Mar 2020
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Document Summary
Forced expiration is an active process that requires the contraction of expiratory muscles. The internal intercostal muscles pull down on the ribs to decrease the volume of the thoracic cavity such that it will become smaller than normal. Abdominal muscles include the external and internal oblique muscles, transversus abdominis and rectus abdominis. They compress the contents of the abdominal cavity and increase abdominal pressure such that contents push up against diaphragm. In addition, the transversus thoracis aids the decrease of the thoracic cavity but plays a very minor role. Define the following lung volumes and capacities. Show the equations for those that can be calculated. Review your notes from lab then define the lung volumes and capacities given. For the capacities, which are combinations of two or more volumes, give the equation to calculate the capacity. Also, indicate which can be directly measured with a spirometer and which need to be calculated based on other values.
