Transcript The Cardiorespiratory System

Chapter 3
The Cardiorespiratory
System
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Purpose
• To provide the fitness professional with a
fundamental knowledge and explanation of
the cardiorespiratory system.
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Objectives
• Following this presentation the participant will be able
to:
– Describe the structure and function of:
• The cardiorespiratory system
• The cardiovascular system
• The respiratory system
– Explain how each of those systems relates to human
movement.
– Go through oxygen-testing procedures.
– Relate how oxygen is related to energy expenditure as well
as the influence that dysfunctional breathing can have on
the kinetic chain.
– Outline the bioenergetic continuum.
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The Cardiorespiratory System
• To maintain a constant state of efficient
operation, the kinetic chain needs to have
support systems.
• The cardiorespiratory system comprises the
cardiovascular and respiratory systems.
• Together they provide the tissues of the
kinetic chain with oxygen, nutrients, protective
agents, and a means to remove waste byproducts.
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Cardiovascular System
• The cardiovascular
system is composed of
the heart, blood, and
blood vessels.
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Heart
• A muscular pump that
rhythmically contracts to
push blood throughout the
body
• Heart muscle is termed
cardiac muscle and has
characteristics similar to
skeletal muscle.
– Cardiac muscle contraction
is involuntary.
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Cardiac Muscle Contraction
• Cardiac muscle fibers are shorter and more
tightly connected.
– Enables the contraction of one fiber to stimulate
the others to contract synchronously
• All cardiac muscle fibers have a built-in
contraction rhythm, and the fibers with the
highest rhythm determine the heartbeat or
heart rate.
– Typical discharge rate (heart rate) is 70–80 beats
per minute
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• The Right Atrium, receives "used blood" from the body. Blood will be
pushed through the tricuspid valve to the
• Right Ventricle, the chamber which will pump to the lungs through the
pulmonic valve to the
• Pulmonary Arteries, providing blood to both lungs. Blood is circulated
through the lungs where carbon dioxide is removed and oxygen added. It
returns through the
• Pulmonary Veins, which empty into the
• Left Atrium, a chamber which will push the Mitral Valve open. Blood then
passes into the
• Left Ventricle. Although it doesn't always look like it in drawings done from
this angle, this is the largest and most important chamber in the heart. It
pumps to the rest of the body. As it pumps, the pressure will close the mitral
valve and open the aortic valve, with blood passing through to the
• Aorta, where it will be delivered to the rest of the body.
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Cardiac Muscle Contraction
• Specialized conduction system of cardiac
muscle that provides the rhythm for the
heart rate includes:
– Sinoatrial (SA) node
• Located in the right atrium.
• Called the “pacemaker” because it
initiates the heartbeat
– Internodal pathways
• Transfers the impulse from the SA to the
atrioventricular (AV) nodes
– Atrioventricular (AV) node
• Delays the impulse before moving on to
the ventricles
– Atrioventricular (AV) bundle (bundle of His)
• Passes the impulse to the ventricles for
contraction via the left and right bundle
branches of the Purkinje fibers.
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Structure of the Heart
• The heart is composed of
four chambers that form two
interdependent but separate
pumps.
– Each side of the
heart has two
chambers.
• Atrium
• Ventricle
• Atrium gathers blood coming
to the heart.
• Ventricles pump the blood
out to the rest of the body.
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Function of the Heart
• Each contraction of a ventricle pushes blood from the
heart into the body.
• The amount of blood that is pumped out with each
contraction of a ventricle is the stroke volume (SV).
• The rate at which the heart pumps is the heart rate
(HR).
• Together, the heart rate and the stroke volume make
up the overall performance of the heart (cardiac
output).
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Monitoring Heart Rate
• Place index and middle fingers around the backside of
the wrist (about one inch from the top of wrist, on the
thumb side).
• Locate the artery by feeling for a pulse with the index
and middle fingers. Apply light pressure to feel the
pulse.
• When measuring the pulse during rest, count the
number of beats in 60 seconds. When measuring the
pulse during exercise, count the number of beats in 6
seconds and add a zero to that number.
– Example: Beats in 6 seconds = 17. Add a zero = 170.
Pulse rate = 170 bpm
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Blood
• Blood acts as a medium to deliver and collect
essential products to and from the body’s tissues.
• The average human body holds about 5 L (roughly
1.5 gallons) of blood at any given time.
• Blood is a vital support mechanism as it:
– Transports oxygen, hormones, and nutrients to specific
tissues and collects waste products
– Regulates body temperature
– Protects from injury and blood loss through its clotting
mechanism to seal off damaged tissue
– Provides specialized immune cells to fight against foreign
toxins within the body, decreasing disease and sickness
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Blood Vessels
• Blood vessels form a closed circuit of hollow
tubes that allow blood to be transported to and
from the heart.
– Arteries transport blood away from the heart.
– Veins transport blood back to the heart.
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Respiratory System
• The second functional component
of the cardiorespiratory system is
the respiratory system.
• Its primary role is to ensure proper
cellular functioning.
• Works intimately with the
cardiovascular system by
providing a means to collect
oxygen from the environment and
transport it to the bloodstream.
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Respiratory System
• The collection and transportation of oxygen is
made possible by the respiratory pump and
the respiratory passageways.
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Respiratory Pump
• Located in the thoracic cavity.
• Provides framework and flexibility to allow for
the expansion and compression needed for
ventilation.
– Divided into two phases
• Inspiratory (inhalation)
• Expiratory (exhalation)
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Respiratory Pump
• Bones
– Sternum, ribs, vertebrae
– Muscles
• Inspiration: Diaphragm, external intercostals, scalenes,
sternocleidomastoid, pectoralis minor
• Expiration: Internal intercostals, abdominals
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Respiratory Passageways
• Air must have
passageways to funnel
it in and out of the lungs
for proper utilization.
• Respiratory
passageways are
divided into:
– Conduction passageway
– Respiratory passageway
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Respiratory Passageways
• Conduction passageways
–
–
–
–
–
–
Nasal cavity
Oral cavity
Pharynx
Larynx
Trachea
Right and left pulmonary bronchi
• Respiratory passageway
– Alveoli
– Alveolar sacs
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Cardiorespiratory Function
• Cardiovascular and respiratory systems make
up the cardiorespiratory system.
– Respiratory system provides the means to gather
oxygen from the environment and transfer it to the
body.
– Cardiovascular system provides the means to
transport oxygen to the tissues of the body.
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Oxygen Consumption
• The usage of oxygen by the body is known as
oxygen consumption.
• Maximal oxygen consumption is generally accepted
as the best means of gauging cardiorespiratory
fitness.
– Submaximal testing procedures have been established to
estimate maximal oxygen consumption.
• Used in a fitness assessment, it can provide
important structural and mechanical information that
may help a fitness professional limit the risk of injury.
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Oxygen and Energy
• Oxygen is the necessary catalyst for sustaining many
bodily functions when activity is prolonged for periods
longer than 30 seconds.
– Aerobic activities last longer than 30 seconds and are
dependent on oxygen for proper execution.
– Anaerobic activities last for only a few seconds and are not
dependent on oxygen for proper execution.
• Energy is essentially the capacity to do work.
– The study of energy in the human body (bioenergetics)
looks at how chemical energy (food) is converted into
mechanical energy (work).
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Bioenergetic Continuum
• Energy can only be productive if it can be captured and
transferred to a place where it can be used.
• The storage and transfer unit within the cells of the body
is typically adenosine triphosphate (ATP).
• The supply of ATP in each cell is limited, and cells must
have a means of producing more.
• There are three main bioenergetic pathways that
produce ATP and are known as the bioenergetic
continuum.
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Bioenergetic Continuum
Pathway
ATP-CP (Creatine
Phosphate)
Glycolysis
Oxidative (Oxygen)
System
Use
Time
Anaerobic
High-intensity, short-duration
activity such as during heavy
weight training
Up to
approximately
10 seconds of
activity
Anaerobic
Moderate- to high-intensity,
moderate-duration activities
such as a typical set of 8–12
repetitions
30–50
seconds of
activity
Aerobic
Lower-intensity, longerduration activities such as
walking on the treadmill for
20–30 minutes
Activities
longer than 2
minutes
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Dysfunctional Breathing
• The importance of all systems in the body
working synergistically can be further
demonstrated in the intimacy between the
cardiorespiratory system and the kinetic chain.
• If there is a dysfunction in the
cardiorespiratory system, this can directly
impact the components of the kinetic chain
and perpetuate into further dysfunction.
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Dysfunctional Breathing
• Alterations in breathing patterns are a prime example
of this relationship.
– During shallow breathing patterns, the secondary respiratory
muscles are used more predominantly.
– If this shallow, upper-chest breathing pattern becomes
habitual, it can cause overuse of muscles including the
scalenes, sternocleidomastoid, levator scapulae, and upper
trapezius.
– These muscles also play a major postural role in the kinetic
chain as they all connect directly to the head and neck.
– Their increased activity and excessive tension often result in
headaches, lightheadedness, and dizziness.
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Summary
•
•
•
•
The respiratory system gathers oxygen from the environment, inhales it
through the nose and mouth, and processes it to be delivered to the
tissues of the body.
As cells use oxygen, they produce carbon dioxide, which is transported
back to the heart and lungs in the deoxygenated blood to be released
through exhalation.
Oxygen is the necessary catalyst for sustaining many bodily functions
when activity is prolonged for periods longer than 30 seconds.
– Aerobic activities last longer than 30 seconds and are dependent
on oxygen for proper execution.
– Anaerobic activities last for only a few seconds and are not
dependent on oxygen for proper execution.
Energy is essentially the capacity to do work.
– The study of energy in the human body (bioenergetics) looks at
how chemical energy (food) is converted into mechanical energy
(work).
– Three bioenergetic pathways include ATP-CP, glycolysis, and
oxidative.
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