Let's learn a bit about how the normal heart and blood vessels work. This basic knowledge will help you to better understand cardiovascular diseases later on.
The cardiovascular or circulatory system is made up of two components: the heart and the blood vessels. The heart is a muscular organ that pumps blood, while the blood vessels carry the blood to circulate all areas of your body.
The Heart
Your
heart is made up of many parts working together to pump blood. An
electrical system controls the heart and uses electrical signals to make
the heart muscles contract. Like any other organ, the heart also
requires oxygen and nutrients from the blood in order to function
properly. Blood supply to the heart is provided by coronary arteries.
If
the coronary arteries get clogged up, such as what happened in coronary
artery diseases, your heart muscles will be damaged and you'll end up
with a heart attack or even a heart failure. If the electrical systems
that control your heart are not working properly, your heart beat will
become irregular, a condition called arrhythmia. It can either beat too
fast (tachycardia), too slow (bradycardia), or even stop entirely
(asystole).
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| Anatomy of the heart |
The heart is divided into four chamber: the right
atrium, right ventricle, left atrium, and left ventricle. The ventricles
are more muscular than the atria because they do most of the pumping
work. The left sided chamber wall are normally thicker than the right
because they handle the systemic circulation while the right sided
chambers handle the pulmonary circulation.
Each
chamber has a valve at its exit that prevents blood from flowing
backwards. The tricuspid valve is at the exit of the right atrium, the
pulmonary valve at the exit of the right ventricle, the mitral valve at
the exit of the left atrium and the aortic valve at the exit of the left
ventricle.
Blood Vessels
There are three major types of blood vessels in our body:
- The arteries are blood vessels that carry the blood away from the heart.
- The capillaries are small vessels which enable the actual exchange of water and chemicals between the blood and the tissue
- The veins which carry blood from the capillaries back toward the heart.
The blood picks up oxygen in the lungs then
flows to the pulmonary veins, to the left atrium, through the mitral
valve, to the left ventricle, through the aortic valve, to the aorta and
finally to the whole body.
After
the oxygen is picked up by our organs, blood from the whole body flows
to the superior and inferior vena cava then to the right atrium, through
the tricuspid valve, to the right ventricle, through the pulmonic
valve, to the pulmonary artery, and finally back to the lungs.
When your heart pumps blood through your arteries, it creates a pulse that you can feel on the arteries close to the skin's surface. For example, you can feel the pulse on the artery inside of your wrist, below your thumb. The normal resting pulse for an adult is 60 to 100 beats per minute.
Other articles on how your body works:
- The human respiratory system consists of a complex set of organs and tissues designed to capture oxygen from the environment and transport the it into the lungs. Read more about how your respiratory system works
- Everyone experience pain at some point of their life. Pain is the most common reason for physician consultation in the United States. Read more about physiology and psychology of pain
- Coughing is a protective reflex to clear the lungs and airways from foreign material. Rapid expulsion of air from the lungs pushes out the offending irritants like microbes, fluids, or mucus.Read more about the cough reflex
