77C H A P T E R

Mark A. Williams

Cardiovascular and Respiratory Anatomy and PhysiologyResponses to Exercise

Cardiovascular and Respiratory Anatomy and PhysiologyResponses to Exercise

Chapter Outline

Cardiovascular anatomy and physiology

Respiratory anatomy and physiology

Cardiovascular and respiratory responses to acute exercise

Cardiovascular and respiratory responses to aerobic and resistance exercise training

External influences on cardiorespiratory response

Human Heart Structure and Blood FlowHuman Heart Structure and Blood Flow

Electrical Conduction System of the HeartElectrical Conduction System of the Heart

Transmission of Cardiac Impulse Through the HeartTransmission of Cardiac Impulse Through the Heart

Normal ElectrocardiogramNormal Electrocardiogram

Arterial and Venous Components of the Circulatory System

Arterial and Venous Components of the Circulatory System

The cardiovascular system transports

nutrients and removes waste products while

helping to maintain the environment for all the

body’s functions. The blood transports oxygen

from the lungs to the tissues for use in cellular

metabolism; blood also transports carbon

dioxide—the most abundant by-product of

metabolism—from the tissues to the lungs,

where it is removed from the body.

Gross Anatomy of the Human Respiratory SystemGross Anatomy of the Human Respiratory System

Contraction and Expansion of the Thoracic CageContraction and Expansion of the Thoracic Cage

The primary function of the

respiratory system is the basic

exchange of oxygen and carbon

dioxide.

The Brain’s Respiratory CenterThe Brain’s Respiratory Center

Blood Pressures in Different Portions of the Circulatory SystemBlood Pressures in Different Portions of the Circulatory System

Acute aerobic exercise results in increased

cardiac output, stroke volume, heart rate,

oxygen uptake, systolic blood pressure, and

blood flow to active muscles and a decrease in

diastolic blood pressure. Resistance exercise

with low intensity and high volume generally

results in similar responses, some to a lesser

degree.

Acute bouts of high-intensity, low-volume

resistance exercise result in increased heart

rate and increased diastolic and systolic blood

pressure but no change in oxygen uptake, no

change or a slight increase in cardiac output,

and no change or a slight decrease in stroke

volume.

Distribution of Tidal Volume in a Healthy Subject at RestDistribution of Tidal Volume in a Healthy Subject at Rest

During aerobic exercise, large amounts of

oxygen diffuse from the capillaries into the

tissues, increased levels of carbon dioxide

move from the blood into the alveoli, and minute

ventilation increases to maintain appropriate

alveolar concentrations of these gases.

Pressure Gradients for Gas Transfer in the Body at RestPressure Gradients for Gas Transfer in the Body at Rest

Aerobic exercise training results in

increased maximal cardiac output and maximal

oxygen uptake, slower resting heart rate,

increased capillarization, improved ventilation

efficiency, increased oxygen extraction, and

OBLA occurring at a higher percentage of

aerobic capacity.

Resistance training is not effective in

improving maximal oxygen uptake. Training

with high intensity and low volume results in no

change or a decrease in capillary density, no

known change in ventilation, no improvement

in oxygen extraction, and very high blood

lactate concentrations. Conversely, low-

intensity, high-volume training may increase

capillarization and improve oxygen extraction.