The student understands the homeostatic role of the cardiovascular system, the basic principles of cardiovascular transport, and the basic structure and function of the components of the system.
- Defines homeostasis.
- Identifies the major body fluid compartments and states the approximate volume of each.
- Lists three conditions, provided by the cardiovascular system, that are essential for regulating the composition of interstitial fluid (ie, the internal environment).
- Diagrams the blood flow pathways between the heart and other major body organs.
- States the relationship among blood flow, blood pressure, and vascular resistance.
- Predicts the relative changes in flow through a tube caused by changes in tube length, tube radius, fluid viscosity, and pressure difference.
- Identifies the chambers and valves of the heart and describes the pathway of blood flow through the heart.
- Defines cardiac output.
- Describes the pathway of action potential propagation in the heart.
- Lists the five factors essential to proper ventricular pumping action.
- States the relationship between ventricular filling and cardiac output (Starling's law of the heart) and describes its importance in the control of cardiac output.
- Identifies the distribution of sympathetic and parasympathetic nerves in the heart and lists the basic effects of these nerves on the heart.
- Lists the major different types of vessels in a vascular bed and describes the morphological differences among them.
- Describes the basic anatomical features and function of the different vessel types.
- Identifies the major mechanisms in vascular control and blood flow distribution.
- Describes the basic composition of the fluid and cellular portions of blood.
A 19th-century French physiologist, Claude Bernard (1813–1878), first recognized that all higher organisms actively and constantly strive to prevent the external environment from upsetting the conditions necessary for life within the organism. Thus, the temperature, oxygen concentration, pH, ionic composition, osmolarity, and many other important variables of our internal environment are closely controlled. This process of maintaining the “constancy” of our internal environment has come to be known as homeostasis. To accomplish this task, an elaborate material transport network, the cardiovascular system, has evolved.
Three compartments of watery fluids, known collectively as the total body water, account for approximately 60% of body weight. This water is distributed among the intracellular, interstitial, and plasma compartments, as indicated in Figure 1–1. Note that about two-thirds of our body water is contained within cells and communicates with the interstitial fluid across the plasma membranes of cells. Of the fluid that is outside cells (ie, extracellular fluid), only a small amount, the plasma volume, circulates within the cardiovascular system. Blood is composed of plasma and roughly an equal volume of formed elements (primarily red cells). The circulating plasma fluid communicates with the interstitial fluid across the walls of small capillary vessels within organs.
Major body fluid compartments with average volumes indicated for a 70-kg human. Total body water ...