Overview of the Respiratory Control System Breathing is one of those things in life that you almost never think about until something goes wrong with it. However, those with pulmonary disease become intensely aware of breathing, as do people who…
Although diffusion is at the very heart of the gas exchange, as we discussed in Chapter 30 , two other parameters are also extremely important. Ventilation and perfusion—both of which require energy—are critical because they set up the partial-pressure gradients…
The complex anatomy of the pulmonary tree, the mechanics of the respiratory system, and the sophisticated carriage mechanisms for O 2 and CO 2 combine to serve two essential purposes: the ready diffusion of O 2 from the alveoli to…
Carriage of O 2 The amount of O 2 dissolved in blood is far too small to meet the metabolic demands of the body Blood carries oxygen in two forms. More than 98% of the O 2 normally binds to…
Acid-base physiology is really the study of the proton, or hydrogen ion (H + ). Although they are present in exceedingly low concentrations in most intracellular and extracellular fluids, protons nevertheless have a major impact on biochemical reactions and on…
The field of pulmonary mechanics —the physics of the lungs, airways, and chest wall—deals with how the body moves air in and out of the lungs, producing a change in lung volume (V L ). When we examine these mechanical…
Comparative Physiology of Respiration External respiration is the exchange of O 2 and CO 2 between the atmosphere and the mitochondria For millennia, people have regarded breathing as being synonymous with life. Life begins and ends with breathing. The Bible…
In the preceding chapters, we examined cardiovascular regulation at several different levels. Powerful systemic mechanisms operate over both the short term and the long term to control mean arterial pressure and cardiac output. Operating independently of these are local mechanisms…
In the preceding chapters, we considered blood flow to peripheral capillary beds as if the “periphery” were a single entity. In this chapter, we break that entity down into some of its component parts. Because each organ in the body…
When faced with a patient who appears seriously ill, clinicians focus their immediate attention on the patient's vital signs: temperature, respiratory rate, pulse, and blood pressure. These parameters are aptly named vital because they reflect the most fundamental aspects of…