Physiology and Testing of Respiratory Muscles

p0010 The respiratory muscles are the only muscles, along with the heart, that have to work continuously, though intermittently, to sustain life. They have to repetitively move a rather complex elastic structure, the thorax, to achieve the entry of air into the lungs and thence effect gas exchange. Their great number mandates that they should interact properly to perform their task despite their different anatomic location, geometric orientation, and motor innervation. They should also be able to adapt to a variety of working conditions and respond to many different chemical and neural stimuli. This chapter describes some aspects of the respiratory muscles’ function that are relevant to the understanding of the way the respiratory muscles accomplish the action of breathing and how their function can be tested in the laboratory.