Lungs Absorb Oxygen Every Part

¶ … Lungs Absorb Oxygen

Every part of the body needs oxygen from the air that is carried throughout the body by the red blood cells in the bloodstream, however because oxygen cannot get into the blood directly, through the skin, the lungs provide a complicated system to absorb it from the air and transfer it into the bloodstream (Way pp).

The lungs lie on either side of the heart and fill the inside of the chest, and are made up of lobes, three on the right and two on the left (Way pp). The inside of the lungs, which looks like a giant sponge, is a mass of fine tubes, the smallest of which end in tiny air sacs called the alveoli (Way pp). There are some 300 million of these alveoli and if spread out, they would cover a piece of ground about the size of a tennis court (Way pp). These alveoli have very thin walls that are crisscrossed with the finest of blood vessels called capillaries (Way pp). The lungs are protected by the rib cage, and in between the ribs are muscles that are essential for breathing, and below the lungs is a dome-shaped muscle called the diaphragm (Way pp). Each lung is covered by two thin layers of tissue, called the pleura, that slide back and forth over each other as we breathe allowing the lungs to expand and contract (Way pp).

The breathing center in the brain receives signals from the body about the amount of oxygen that is needed, then the brain sends messages along nerves to the breathing muscles between the ribs, which allows the right amount of air to be breathed into the lungs (Way pp). With each breath, air is drawn into the nose or mouth, then down through the throat and into the windpipe, or trachea, which splits into two smaller air tubes called the bronchi that go to each lung (Way pp). The air then passes down the bronchi that divide another 15 to 25 times into thousands of smaller airways, called bronchioles, until the air reaches the alveoli (Way pp). Inside the alveoli, oxygen moves across the paper-thin walls to the capillaries, the tiny blood vessels, and then into the blood, where it is picked up by chemicals, haemoglobin, in the red blood cells ready to be carried throughout the body (Way pp). At the same time, waste products from the body, in the form of carbon dioxide, come out of the capillaries back into the alveoli, ready to be breathed out (Way pp). Freshly oxygenated blood is carried from the lungs to the left side of the heart which pumps blood around the body through the arteries, and once the oxygen is used up, the blood returns, through the veins, to the right side of the heart (Way pp). From there, it is pumped to the lungs so that the carbon dioxide can be removed and more oxygen taken in (Way pp).