What are veins responsible for?
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.
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 veins are responsible for carrying oxygenated blood from the lungs back to the left atrium of the heart. This differentiates the pulmonary veins from other veins in the body, which are used to carry deoxygenated blood from the rest of the body back to the heart. These carry blood from the right lung.
- The deep veins play a significant role in propelling blood toward the heart. The one-way valves in deep veins prevent blood from flowing backward, and the muscles surrounding the deep veins compress them, helping force the blood toward the heart, just as squeezing a toothpaste tube ejects toothpaste.
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.
- Veins can be categorized into four main types: pulmonary, systemic, superficial, and deep veins.
- Pulmonary veins carry oxygenated blood from the lungs to the left atrium of the heart.
- Systemic veins return oxygen-depleted blood from the rest of the body to the right atrium of the heart.
- 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.
- The chief difference between arteries and veins is the job that they do. Arteries carry oxygenated blood away from the heart to the body, and veins carry oxygen-poor blood back from the body to the heart. Your body also contains other, smaller blood vessels.
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.
- One answer you're likely to hear is that veins look blue because the blood inside actually is blue, because it's deoxygenated. If you wonder why you've never seen blue blood before, someone might tell you that's because when you bleed, the blood is oxygenated upon contact with air, and immediately turns red.
- Answer: The main job of the Circulatory System is to get food and oxygen to all the cells in the body. It also carries away waste materials such as Carbon Dioxide produced in the body. The Circulatory System is made up of three main parts: The heart, the blood vessels and the blood.
- Human blood is always red. The only difference is that when it is oxygenated, it is a bright red, and when it is depleted of oxygen, it is a darker red. If you are brave enough to look at the blood being drawn, it is notable dark red, it is the blood from your veins that is low in oxygen.
Updated: 18th November 2019