BIOLOGY 20 Lecture Notes - Lecture 32: Elastic Fiber, Bronchiole, East Los Angeles College
Document Summary
Respiratory airflow is governed by the same principles of flow, pressure and resistance s blood flow. Boyle"s law: at a constant temperature, the pressure of a given quantity of gas is inversely proportional to its volume. If the lungs contain a quantity of a gas and the lung volume increases, their internal pressure falls: if the pressure falls below atmospheric pressure the air moves into the lungs. If the lung volume decreases, intrapulmonary pressure rises: if the pressure rises above atmospheric pressure the air moves out of the lungs. Passive process achieved mainly by the elastic recoil of the thoracic cage. Raises intrapulmonary pressure to about 3+mm hg. Air flows down the pressure gradient and out of the lungs. Accessory muscles raise intrapulmonary pressure as high as 30+ mm hg. Massive amounts of air moves out of the lung. Arthritis and other skeletal disorders that affect the articulations of the ribs and spinal column also reduce compliance.
