This section describes ways to recognize cardiovascular emergencies (determined by heart function and circulation) and provide first aid. You will learn how to assist a patient during a heart attack and perform cardiopulmonary resuscitation during cardiac arrest.
Circulatory system
The circulatory system, along with the respiratory system, is involved in delivering oxygen to all parts of the body. Through it, nutrients and waste products are supplied to the body. The circulatory system includes the heart, blood vessels and blood.
The heart is a muscular organ located behind the sternum. Through arteries and veins, the heart circulates blood throughout the body, re-
pumping about five liters of blood per minute.
Arteries are blood vessels that carry blood from the heart to other parts of the body. There are also coronary arteries that supply blood specifically to the heart tissue. The arteries branch into even smaller vessels, ending in thin capillaries that allow the exchange of oxygen and carbon dioxide in the cells. After this, the oxygen-deprived blood flows through the veins back to the heart. The heart then pumps the blood to the lungs, where it is reoxygenated before returning to the heart and traveling to other parts of the body. This process is called the circulatory cycle. Figure 6-3 shows how blood flows through the heart during this cycle.
The work done by the heart to pump blood is called contraction. The heart's electrical system causes it to beat continuously at a rate of 60-80 beats per minute (in an adult). The pulsation felt with each contraction in the arteries located close to the surface of the skin is called the pulse.
To supply oxygen to the body's cells and ensure the functioning of all functions, the heart must contract uninterruptedly.