The circulatory system is responsible for the flow of blood in the body. It carries oxygen and nutrients to various parts of your organs such as the liver, the lungs and the brain. With the help of the blood vessels -- the complicated network of tubes inside the body -- blood is transported throughout your body.
There are times when the blood vessels are blocked by substances such as bad cholesterol, thus, the amount of blood flow is restricted. This forces the heart to pump harder to fuel and clean the body. The harder the heart pumps, the more blood presses against the walls of the blood vessels. If this occurs for a long time and the blood pressure remains high, hypertension occurs. Thus, the body will require blood pressure pills or blood pressure meds to lower the pressure. Blood pressure medicines can also prevent heart attack.
There are three types of major blood vessels. The arteries carry the blood away from the heart. The capillaries allow the exchange of water and nutrients between the blood and the tissues. The capillaries are also responsible for the transport of blood from the arteries to the veins. Finally, the veins are responsible for the transport of blood from the capillaries back to the heart.
The arteries are classified into two types. Pulmonary arteries carry the blood in the heart to pick up oxygen in the lungs. Systemic arteries are responsible for the delivery of blood to the rest of the body. The largest artery in the body is the aorta. Being the main systemic artery, the aorta starts in the heart and breaks into smaller arteries that send blood to the artery of the brain (brachiocephalic artery), arteries of the heart (coronary arteries) and the lower body.
Responsible for transporting blood to the heart, the veins are grouped into four major types. The pulmonary veins bring blood rich in oxygen to the heart. On the other hand, the systemic veins return oxygen-depleted blood from various areas of the body to the heart. Superficial veins are those on the skin. Deep veins are found deep in muscle tissues and are usually found with a partner artery such as the coronary veins and arteries.
Sometimes, when we get wounded in the arm for example, the superficial veins in the area are damage and blood flows out of the body. Our body creates a blood clot around the wound to prevent further blood from going out. This is our body's way of healing itself. There are also cases when very small blood vessels burst in the eye, etc. In the case of the common painless blood spot in the eye, the bleeding results from a break in a small blood vessel in the white portion of the eye.
Located in the tissues of the body, capillaries are very small tubes 5 to 10 micrometers in diameter that transfer the blood from the arteries to the veins. Their walls are thin and composed of a single layer of overlapping flat cells called endothelium. The capillaries are also responsible for the exchange of chemicals such as carbon dioxide, wastes, oxygen and nutrients that are to be utilized or disposed of by the body.
To sum up, the blood vessels play an important part in the working of the body. Aside from maintaining the flow of blood within the body, the blood vessels also play a role in distributing nutrients to all areas of the body and flushing out the toxins and waste.