375
5
T
Control of
Cardiovascular
Function
17
C h a p t e r
Organization of the Circulatory System
Pulmonary and Systemic Circulations
Volume and Pressure Distribution
Principles of Blood Flow
Pressure, Resistance, and Flow
Flow in Series and Parallel Vessels
Velocity, Cross-Sectional Area, and Flow
Laminar Versus Turbulent Flow
Wall Tension, Radius, and Pressure
Vascular Distensibility
The Heart as a Pump
Functional Anatomy of the Heart
Pericardium
Myocardium
Endocardium
Heart Valves and Fibrous Skeleton
Electrical Activity of the Heart
Cardiac Conduction System
Action Potentials
Absolute and Relative Refractory Periods
Arrhythmias and Conduction Disorders
Electrocardiography
Cardiac Cycle
Ventricular Systole and Diastole
Atrial Filling and Contraction
Regulation of Cardiac Performance
Preload
Afterload
Cardiac Contractility
Heart Rate
The Systemic Circulation and Control of Blood Flow
Blood Vessels
Arterial System
Venous System
Capillaries
Lymphatic System
The Microcirculation
Autoregulation of Blood Flow
Endothelial Control of Blood Flow
Humoral Control of Blood Flow
Collateral Circulation
Neural Control of Blood Flow
he main function of the cardiovascular or circulatory
system, which consists of the heart and blood ves-
sels, is transport. The circulatory system transports and
distributes oxygen and nutrients needed for metabolic
processes to the tissues, carries waste products from
cellular metabolism to the kidneys and other excretory
organs for elimination, and circulates fluids, electro-
lytes, and hormones needed to regulate body function.
This process is carried out with exquisite precision so
that oxygen and nutrient delivery is exactly matched to
meet tissue needs.
Organization of the Circulatory
System
The circulatory system can be divided into two parts:
the
pulmonary
(or
central
)
circulation,
which moves
blood through the lungs and creates a link with the gas
exchange function of the respiratory system, and the
systemic
(or
peripheral
)
circulation
, which moves blood
throughout all the other tissues of the body (Fig. 17-1).
Pulmonary and Systemic Circulations
The pulmonary circulation consists of the right side
of the heart, the pulmonary arteries and arterioles,
the pulmonary capillaries, and the pulmonary veins.
The large pulmonary vessels are unique in that the
Circulatory
Function
U N I T
