Chapter 3 The Cardiorespiratory System

1. Chapter 3The Cardiorespiratory System

2. Purpose • To provide the fitness professional with a fundamental knowledge and explanation of the cardiorespiratory system.

3. 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.

4. 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 by-products.

5. Cardiovascular System • The cardiovascular system is composed of the heart, blood, and blood vessels.

6. 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.

8. 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

9. 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.

10. 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.

11. 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.

12. 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).

13. 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

14. 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

15. 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.

16. 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.

17. Respiratory System • The collection and transportation of oxygen is made possible by the respiratory pump and the respiratory passageways.

18. 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)

19. Respiratory Pump • Bones • Sternum, ribs, vertebrae • Muscles • Inspiration: Diaphragm, external intercostals, scalenes, sternocleidomastoid, pectoralis minor • Expiration: Internal intercostals, abdominals

20. 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

21. Respiratory Passageways • Conduction passageways • Nasal cavity • Oral cavity • Pharynx • Larynx • Trachea • Right and left pulmonary bronchi • Respiratory passageway • Alveoli • Alveolar sacs

22. 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.

23. 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.

24. 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).

25. 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.

26. Bioenergetic Continuum

27. 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.

28. 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.

29. 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.