LESSON 3
CARDIAC ARREST (DEFIBRILLATION)
Section I. REVIEW OF THE CARDIOVASCULAR SYSTEM AND
THE RESPIRATORY SYSTEM
3-1.
DEFINITIONS
Some of the terms used in this and following lessons are defined below.
a. Casualty. The casualty is the person with the medical problem, such as a
person who is not breathing.
b. Rescuer. The rescuer is the person who is assisting the casualty; for
example, the person who is giving mouth-to- mouth resuscitation to the casualty.
c. Airway. The airway consists of the body structures through which air from
the atmosphere passes while going to the lungs. The airway includes the oral and
nasal cavities (mouth and nose), pharynx (throat), larynx (voice box), trachea
(windpipe), and bronchi (two tubes leading from the trachea to the lungs).
d. Sign. A sign is anything that the rescuer can tell about the casualty's
condition by using his own senses. For example, a rescuer can see a wound, hear
breathing difficulty, feel that the casualty has a fever by touching the casualty's skin, and
smell an unusual odor on the casualty's Is breath, a possible sign of poisoning.
e. Symptom. A symptom is any change from the norm which is felt by the
casualty but which cannot be directly or objectively sensed by the rescuer. Examples of
symptoms felt by the victim are chest pains, nausea, a headache, and mental
confusion. An injury can produce both signs and symptoms; for example, pain which
only the victim can feel and a bump or bruise which can be viewed by others.
f. Aggravate. To aggravate a wound means to make it worse. For example,
moving a person with a fractured leg before the leg is splinted can cause the sharp ends
of the broken bone to cut nerves and blood vessels that were not damaged before the
person was moved.
3-2.
IMPORTANCE OF FOOD, OXYGEN, AND THE CARDIOVASCULAR SYSTEM
The human body is composed of cells. The average adult's body is made up of
around eighty trillion (80,000,000,000,000) living cells. Each living cell needs energy to
survive. Cells obtain energy through oxidation. That is, they combine a source of
potential energy with oxygen to liberate energy. The sources of potential energy come
from the food (carbohydrates, fats, and proteins) that is processed into usable units by
MD0571
3-2