Why do we have veins?
The blood going out to your body in the arteries is full of oxygen, which makes the blood bright red. But the blood coming back from your body in the veins is darker because your body parts have used up the oxygen in the blood. That's why veins look purple or blue.
The arteries are perceived as carrying oxygenated blood to the tissues, while veins carry deoxygenated blood back to the heart. This is true of the systemic circulation, by far the larger of the two circuits of blood in the body, which transports oxygen from the heart to the tissues of the body.
- Arteries are the strong, elastic vessels that take oxygenated blood from the heart out to parts of our body to deliver oxygen. Arterial blood is a rich red color, due to the oxygen bonded with hemoglobin on the red blood cells. After the oxygen has been dropped off, the blood is returned back to the heart by the veins.
- pulmonary artery
- But if you took all the blood vessels out of an average child and laid them out in one line, the line would stretch over 60,000 miles. An adult's would be closer to 100,000 miles long. There are three kinds of blood vessels: arteries, veins, and capillaries.
Blood flows through a system of blood vessels, which are veins and arteries. Arteries carry blood rich in oxygen from your heart to all regions of the body. The function of veins is to transport the blood back to the heart. Superficial veins are responsible for transporting as little as 10% of the blood in the legs.
- Capillaries are very thin blood vessels that were first discovered in frog lungs in 1661. They bring nutrients and oxygen to tissues and remove waste products. In this lesson, you will learn more about their structure and function.
- Blood is always red, actually. Veins look blue because light has to penetrate the skin to illuminate them, blue and red light (being of different wavelengths) penetrate with different degrees of success. The oxygen-rich blood is then pumped out to your body through your arteries. It's bright red at this point.
- Capillaries are the smallest of the body's blood vessels. They are only one cell thick, and they are the sites of the transfer of oxygen and other nutrients from the bloodstream to other tissues in the body; they also collect carbon dioxide waste materials and Continue Scrolling To Read More Below
The structure of veins is similar to that of arteries, again consisting of three layers: Tunica Adventitia: This is the strong outer covering of arteries and veins which consists of connective tissues, collagen and elastic fibres. Tunica Media: This is the middle layer and consists of smooth muscle and elastic fibres.
- The arteries are perceived as carrying oxygenated blood to the tissues, while veins carry deoxygenated blood back to the heart. This is true of the systemic circulation, by far the larger of the two circuits of blood in the body, which transports oxygen from the heart to the tissues of the body.
- Your blood is actually always red! Blood in your veins has very little oxygen and is a dark red color that looks almost blue when covered by your skin. Your arteries have bright red blood because it has a lot of oxygen in it that is being carried throughout your body to be used by tissues.
- An artery is a vessel that carries blood away from the heart and toward other tissues and organs. Arteries are part of the circulatory system, which delivers oxygen and nutrients to every cell of the body.
Updated: 18th November 2019