How veins and arteries differ
The circulatory system contains veins and arteries. Although they both carry blood, there are major differences in the role that each one plays as part of this essential system of the body. The arteries carry blood filled with oxygen to the rest of the body. There are also pulmonary and umbilical arteries, whose function is to bring the blood depleted of oxygen from the heart to the lungs where it can get replenished with a supply of oxygen. The function of the veins is to carry blood that has depleted its oxygen supply from the rest of the body back to the heart. There are also pulmonary and umbilical veins that bring oxygen-filled blood from the lungs to the heart.
The main role of arteries in the body is to bring oxygen and nutrients to the body by means of the blood. The arteries also take away the toxins, waste and chemicals from the cells and tissues. This helps to maintain the chemical balance within the cells and allows for the transport of protein to the immune system as well as to the cells and tissues where it is needed.
There are different types of arteries: systemic, pulmonary, arterioles and aorta. They are thick and have strong muscles because they have to deal with the pulsation of the blood being pumped from the heart. There are small tubules in the arteries. Connective tissue covers the outer layer to protect the muscle tissues of the middle layer. This connective tissue contracts each time the heart beats and pumps blood. Finally the inner layer is made up of endothelial cells that are smooth so that the blood can flow through easily.
The role of the veins is to carry the deoxygenated blood from the cells and tissues of the body back to the heart from which it is sent to the lungs for more oxygen. These are not as thick as the arteries and are smaller. They are tube shaped and are elastic.
There are four types of veins: superficial, deep, pulmonary and systemic. Superficial veins lie just under the skin and do not have arteries that correspond to them. The deep veins are much deeper than superficial veins. Pulmonary veins are the ones that bring the oxygenated blood from the lungs to the heart and the deoxygenated blood to the heart from the tissues and cells where it was depleted. Even though they do have the same type of tissues as arteries do, but veins do not contract with heart beats.
- Arteries take the blood containing oxygen from the heart and bring it to the cells and tissues of the body. Veins take the deoxygenated blood from the cells and tissues and bring it back to the heart.
- Arteries are thick and strong and they contract between heart beats. Veins are not as thick and they do not contract.
- The pressure of the blood flowing through arteries is very high, but it Is much lower in the veins.
- There are no valves in arteries, but veins do have valves to prevent the blood from flowing back.
- When there is no blood flowing through them, veins collapse, but arteries do not.