Multiple Functions of the Kidneys Most people are familiar with one important function of the kidneys—to rid the body of waste materials that are ingested or produced by metabolism. A second function that is especially critical is to control the…
The maintenance of a relatively constant volume and stable composition of the body fluids is essential for homeostasis. Some of the most common and important problems in clinical medicine arise because of abnormalities in the control systems that maintain this…
Circulatory shock means generalized inadequate blood flow through the body to the extent that the body tissues are damaged, especially because too little oxygen and other nutrients are delivered to the tissue cells. Even the cardiovascular system itself—the heart musculature,…
Function of the heart valves was discussed in Chapter 9 , where we pointed out that closing of the valves causes audible sounds. Ordinarily, no audible sounds occur when the valves open. In this chapter, we first discuss the factors…
One of the most important ailments treated by the physician is cardiac failure (heart failure). This ailment can result from any heart condition that reduces the ability of the heart to pump enough blood to meet the body’s needs. The…
In this chapter we consider the following: (1) blood flow to the skeletal muscles; and (2) coronary artery blood flow to the heart. Regulation of each of these types of blood flow is achieved mainly by local control of vascular…
Cardiac output is the quantity of blood pumped into the aorta each minute by the heart. This is also the quantity of blood that flows through the circulation. Because cardiac output is the sum of the blood flow to all…
In addition to the rapidly acting mechanisms for regulation of arterial pressure discussed in Chapter 18 , the body also has powerful mechanisms for regulating arterial pressure week after week and month after month. This long-term control of arterial pressure…
Nervous Regulation of the Circulation As discussed in Chapter 17 , adjustment of blood flow in the tissues and organs of the body is mainly the function of local tissue control mechanisms. In this chapter, we discuss how nervous control…
Local Control of Blood Flow in Response to Tissue Needs A fundamental principle of circulatory function is that most tissues have the ability to control their own local blood flow in proportion to their specific metabolic needs. Some of the…