Physiology of Respiration and Circulation (Magill’s Medical Guide, Sixth Edition)
Every cell in the human body needs a constant and steady supply of oxygen. The delivery of oxygen is possible only through a continuous movement of oxygen-rich blood, with the heart and lungs working efficiently together. To survive, the body must have a functioning heart and lungs, or an outside force that makes both organs function artificially. Two major life-threatening conditions include respiratory arrest (cessation of breathing) and cardiac arrest (cessation of heartbeat). Death is certain unless something is done to put oxygen into the blood and circulate it throughout the body. Cardiopulmonary resuscitation (CPR) is the artificial action of putting oxygen into the lungs and making the heart pump blood throughout the body. By understanding the anatomy and physiology of the heart and lungs, and their entire systems, it is easier to see how CPR can help a person who is not breathing and whose heart is not pumping blood.
The respiratory system. This system has many parts, from the nose down to the smallest sacs of the lungs. After air is taken in through the nose or mouth, it moves farther down into the throat (pharynx), past the larynx (voice box) and the trachea (windpipe). Next, the inhaled air goes through specialized tubes called bronchi, one connected to each lung. From this larger tube, the air passage narrows into smaller tubes called bronchioles. The bronchioles become smaller...
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Indications and Procedures (Magill’s Medical Guide, Sixth Edition)
Whether the heart is functioning is not a matter of yes or no, black or white. There are many gray areas that represent a heart that is beating but not working in a manner that will support life. One of these gray areas includes many types of abnormal beats, known as arrhythmias, or abnormal rhythms. If the heart is beating too fast (tachycardia) or extremely slowly (bradycardia), then it cannot supply body tissues with needed oxygenated blood. A constant and even pressure of blood flow must also be maintained.
The amount of pressure inside the circulatory system varies. Blood pressure is measured as systolic pressure over diastolic pressure. In a blood pressure reading of 120/70, the top number, 120, indicates the amount of pressure on the walls of the vessels when the heart is beating (contracting). The bottom number, 70, reflects the amount of pressure on the vessel walls between beats when the heart is at rest. In cases when both numbers are extremely low or high, the system is not working properly and urgent measures must be taken to identify and fix the problem.
When either the circulatory or the respiratory system is not able to perform properly, the entire body suffers quickly. Without oxygenated blood, brain damage begins within four to six minutes. While sitting, the human heart pumps sixty to one hundred times each minute, moving about 5.5 liters of blood throughout the body every minute. The...
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Perspective and Prospects (Magill’s Medical Guide, Sixth Edition)
Over the years, huge advances have been made in resuscitation measures. More lives have been saved by the training of medical personnel to administer advanced life support before a patient reaches the hospital. Lifesaving drugs and defibrillation have greatly decreased the death rate for heart attack victims and cardiac patients. With the continued training of emergency medical technicians, the survival rate can improve as a result of earlier and more aggressive medical treatment.
Medical treatment could be avoided entirely, however, if more preventive health measures were implemented. With continued research identifying risk factors, the public can be educated about how to prevent conditions that lead to heart attacks. Among the known risk factors are cigarette smoking, hypertension (high blood pressure), high cholesterol and triglycerides, lack of exercise, excess weight and improper nutrition, stress, and diabetes mellitus. Three risk factors cannot be changed: predisposing heredity, gender (men are more likely to have heart attacks), and increasing age.
With further research, the first group of risk factors may be addressed in society through extensive education, but heart attack rates cannot be curbed unless people change their lifestyles. An understanding of heredity, gender, and age risk factors can bring changes in these rates only through further research into their relationship to heart...
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For Further Information: (Magill’s Medical Guide, Sixth Edition)
American Heart Association. Heartsaver CPR. Dallas, Tex.: Author, 2006. This handbook is used when teaching the CPR courses offered by the American Heart Association. Offers easy-to-understand descriptions of anatomy and physiology, and lists health risk factors. It comes with a supplemental CD with video clips of CPR and relief of choking procedures.
_______. “2005 AHA Guidelines for CPR and ECC.” Circulation 1112, no. 24 (December 12, 2005): IV 1-IV 203. This journal provides a detailed description of the new CPR guidelines made by the panel of experts at the International Consensus conference in February, 2000. Also available at http://www .americanheart.org.
Cayley, William E., Jr. “2005 AHA Guidelines for CPR and Emergency Cardiac Care.” American Family Physician 73, no. 9 (May 1, 2006): 1645. Provides a concise overview of the changes to care.
Hamilton, Glenn C., et al. Emergency Medicine: An Approach to Clinical Problem-Solving. 2d ed. New York: W. B. Saunders, 2003. Addressed to students of medicine, this text provides a detailed, well-written script for the clinical setting. Facilitates the reader’s understanding of the emergency scene. Actual medical cases are integrated into the chapters in order to reinforce concepts.
Handal, Kathleen A. The American Red Cross First Aid and Safety Handbook. Boston: Little, Brown, 1992. A...
(The entire section is 336 words.)