Chapter 18
- Cardiac Physiology
- Lena S. Sun
- Johanna Schwarzenberger
Introduction
The modern concept of circulation and that the heart is the generator
for the circulation was initially advanced by Harvey in 1628. Since that time, the
field of cardiac physiology has developed to now include the physiology of the heart
as a pump, cellular and molecular biology of the cardiomyocyte, and regulation of
cardiac function by neural and humoral factors. Moreover, we now appreciate that
physiology of the heart is only a component of the interrelated and integrated cardiovascular
and circulatory physiology. This chapter will discuss only the physiology of the
heart. It begins with the physiology of the intact heart. The second part of the
chapter focuses on cellular cardiac physiology. Finally, we will briefly discuss
the various factors that regulate cardiac function.
The basic anatomy of the heart consists of two atria and two ventricles
providing two separate circulations in series. The pulmonary circulation, a low-resistance
and high-capacitance vascular bed, receives output from the right side of the heart,
and its chief function is bidirectional gas exchange. The left side of the heart
provides the output for the systemic circulation. It functions to deliver oxygen
and nutrients and remove CO2
and metabolites from various tissue beds.
