INTRODUCTION TO THE LUNGS By Jamie Holguin In this article, I will discuss the anatomy and physiology of the human lung. Furthermore, I will explain how a disease such as Cystic Fibrosis can affect and alter the normal function of the human lung. In 2008, Approximately 30,000 Americans have CF and there are an estimated 1,000 new cases diagnosed each year. Finally, I will discuss how a medical device, such as the spirometer, can be very useful in not only diagnosing but also in the treatment of such a disease. ANATOMY & PHYSIOLOGY OF THE LUNG The human body contains a pair of lungs, one on the right side of the chest and another on the left side of the chest. The lungs size is 10 to 14in length, 4 to 6 inches in width, and weighs approximately 2.5 pounds [right 360570 grams and left 325-480 grams. The lung is made of sections called lobes (Figure 1). Both lungs are surrounded and protected by the ribcage. The main purposes of the lungs are to provide oxygen and to remove carbon dioxide. Oxygen is delivered into the body by breathing air in through the nose or mouth. It is better to breath air in through the nose since it is a better filter [nose hair] than the mouth.
After air has entered through the nose or mouth it travels down the trachea (windpipe). The trachea divides into two tubes, one going to the right lung and the other going to the left. These tubes are called the bronchi. The bronchi continue to divide into smaller tubes called the bronchioles. The bronchioles eventually end up in the alveoli (Figure 2), which are very tiny air sacs. In the alveoli is where oxygen from the air is absorbed into the blood. Carbon dioxide travels from the blood to the alveoli where it can be exhaled. There are over 200 million alveoli in the human lung. Not all of them are being used at the same time. Most of them are stored as back ups in case. The diaphragm (Figure 3) is a large muscle located under the lungs that is used when breathing. The diaphragm also separates the lungs from the other organs below, such as the stomach, intestines, etc…. When the diaphragm moves down the ribs flare outward causing the lungs to expand and draw in air. This is called inhalation or inspiration. When the diaphragm relaxes, air leaves the lungs and they go back to their original position. This is called exhalation or expiration. CYSTIC FIBROSIS Cystic Fibrosis (CF) is a genetic disease