Module 7: The ASEAN World of Medicine
Table of Contents
Reading Text & Presentation
7.2 The human heart
7.2.1 The cardiovascular system
It is said that the heart is the most important part of the human body. A person might survive without certain parts of the body, but once the heart stops beating it doesn’t take long for a person to die.
The cardiovascular system, or circulatory system, involves the heart and blood vessels (arteries, veins, and capillaries). The main ‘driver’ is the heart as it pumps the blood, and this circulation serves to transfer or transport oxygen, nutrients, waste products, immune cells, and signalling molecules like hormones around the body. The blood vessels carry blood, which consists of fluid that carries cells in the circulation. Some of these cells move from tissue to blood vessels and back, as well as to the spleen and bone marrow.
Figure 1 shows a simplified diagram of the heart and circulatory system:
Figure 1
The colour provides a simple way to indicate oxygenated blood (blood containing oxygen) – red; and de-oxygenated blood (after the oxygen has been transferred) – blue; in its path around the body.
The vessels at the top of the diagram lead to the head and arms. The vessels at the bottom of the diagram lead to the liver, kidneys, intestines and legs.
KEY:
Heart sections: 1. Right atrium 2. Left atrium 3. Right ventricle 4. Left ventricle
Artery: 5. Aorta
Organs: 6. Lungs
Figure 2 shows a more detailed diagram of the heart:
Figure 2
(Source: See References: Heart Anatomy)
The exchange of blood pumping through the heart through the atriums and ventricles is facilitated by a series of valves.
Figure 3 shows the detail of veins, arteries and valves:
Figure 3
(Source: See References: Heart Valves)
The human heart is a vital organ that functions as a pump, providing a continuous circulation of blood through the body, by way of the cardiac cycles. The heart is contained in the mediastinum in the thoracic cavity of the thorax.
