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ACE Group Fitness Instructor Manual
Chapter
 Exercise
1
Physiology
CARDIO-RESPIRATORY SYSTEM
1
Components of the cardiorespiratory system

Blood

Vessels

Heart

Lungs

Airways
2
Components of the cardiorespiratory system

Blood: carries nutrients, gases,
wastes, and hormones




Nutrients—carbohydrates, fats,
and proteins
Gases—oxygen and carbon dioxide
(carried in red blood cells on the
protein hemoglobin)
Wastes—lactic acid and other
metabolic by-products
Hormones—sympathetic and
parasympathetic nervous system
activation
3
Components of the cardiorespiratory system

Vessels: transport system for
blood throughout the body



Arteries—carry oxygenated blood
away from the heart (with the
exception of the pulmonary artery)
Veins—carry de-oxygenated blood to
the heart (with the exception of the
pulmonary vein)
Capillaries—tiny vessels across which
the exchange of gases, nutrients, and
wastes occurs between the blood and
the cells of the body
4
Arterial Blood Pressure


Expressed as systolic/diastolic

Normal is 120/80 mmHg

High is ≥140/90 mmHg
Systolic pressure (top number)


Pressure generated during ventricular contraction
(systole)
Diastolic pressure

Pressure in the arteries during cardiac relaxation
(diastole)
Measurement of Blood Pressure
Blood Pressure throughout circulatory system
Arteries & Veins
The Skeletal Muscle Pump


Rhythmic skeletal
muscle contractions
force blood in the
extremities toward
the heart
One-way valves in
veins prevent
backflow of blood
Components of the cardiorespiratory system

Heart: a four-chambered
pump responsible for
distributing blood to the lungs
and to the rest of the body


Right side—receives venous
blood returning from the
body
Left side—receives arterial
blood returning from the
lungs
11
Components of the cardiorespiratory system

Heart

Atria—the two upper chambers of the heart

Ventricles—the two lower chambers of the heart
12
Components of the cardiorespiratory system

Heart--Blood distribution

The left and right sides of the
heart contract simultaneously.

At the same time the blood from
the right ventricle is pumped to
the lungs through the pulmonary
arteries, the blood from the left
ventricle is ejected to the rest of
the body through the aorta.
13
Heart
Anatomy
Figure 12.2
Copyright © 2007 Lippincott Williams & Wilkins
Components of the cardiorespiratory system

Heart


Systole—contraction phase of the
cardiac cycle
Diastole—relaxation phase of the
cardiac cycle


During diastole, the heart muscle is
supplied with oxygen through the
coronary arteries.
Having a high level of cardiorespiratory
fitness means the heart spends more
time in diastole at rest and during
submaximal exercise due, in part, to a
decreased resting heart rate (RHR).
15
Components of the cardiorespiratory system


Lungs: encase the smaller
branches of the trachea that
allow gas exchange between the
blood and the atmosphere
Airways: transport system for
carrying gases into and out of
the body—commonly referred to
as the bronchial tree

Alveoli—microscopic ducts responsible
for gas exchange in the lungs

The lungs contain an estimated 300
million alveoli providing a surface area
of approximately 230 square feet (the
size of a tennis court).
16
Major Organs of the Respiratory System
Alveoli
Pulmonary Ventilation




Pulmonary ventilation is the process by which
air is moved into and out of the lung
(inspiration, expiration)
Inspiration is an active process in which the
diaphragm and intercostal muscles contract,
increasing dimensions and volume of the
thoracic cage
Expiration at rest is normally passive; the
inspiratory muscles relax, decreasing the
thoracic cage
Forced inspiration and expiration are active
processes involving accessory muscles