How Smoking Affects the Lungs
{"Image DocumentName": "How Smoking Affects the Lungs", "Image ImageDescription": "Ch 23 part II Respiration. How Smoking Affects the Lungs. Breathing exposes your respiratory tissues to potentially damaging chemicals. Tobacco smoke. damages the cells that line the bronchi and trachea. interferes with the normal cleansing mechanism of the respiratory system: more toxin-laden smoke particles reach & damage the lungs\u2019 alveoli. Student Misconceptions and Concerns. 1. The exchange of oxygen and carbon dioxide in the lungs does not result in exhaled air depleted of all oxygen and blood with no carbon dioxide remaining. However, students may think that this is true. Instead, gas exchange in the lungs results in proportional changes. You may point out to your students that if the air we exhale had no oxygen, there would be little benefit to mouth-to-mouth resuscitation! 2. Many students still struggle with diffusion as the main mechanism for gas transport. Before discussing gas transport, ask your class to explain why oxygen moves out of blood in body tissues and into blood in the lungs. Why doesn\u2019t the process get mixed up? 3. Students might misunderstand how the cilia lining our respiratory passages work. Cilia do not filter the air like a comb. Instead, cilia are covered by a layer of mucus. Dust particles adhere to sticky mucus, which is then swept up the respiratory tract by the cilia. If students clear their throats, they will identify the fate of this mucus. We swallow after clearing our throats! 4. Students often confuse the structures and functions of the trachea and esophagus. To help them distinguish, point out that the trachea has a structure and function like the hose of a vacuum cleaner. The rigid ribbed walls of the trachea keep the tube open as air is sucked through it. The esophagus, however, relies upon rhythmic changes in the shape of the walls (peristalsis) to propel food toward the stomach. If the esophagus had stiff walls, it would not be able to perform this function. 5. Some basic models of the human diaphragm your students might have experienced do not properly represent the anatomy of the diaphragm. When relaxed, the diaphragm arches upward toward the heart. When contracted, the diaphragm flattens. This dropping of the diaphragm compresses the stomach, moving it downward and outward. After a large meal, it is more difficult to breathe because a full stomach does not move as easily. Teaching Tips. 1. Some of your students may have been taught to breathe deeply by actively extending their stomach outward. Ask your class to explain why this permits a deeper breath (it allows the diaphragm to move even lower with less resistance from body organs in the abdominal cavity). 2. Students are often surprised to learn that the mineral iron in our diets is the same iron we use for building automobiles, pots, and pans. You might wish to point out that just as rust forms by the reaction of oxygen and iron, the red color of blood is due to the bonding of oxygen to iron in our red blood cells. Further, when we have a cut in our mouth, the familiar metal taste may well be due to the presence of iron in our blood. 3. The basic principles of the vocal cords can be demonstrated by inflating a balloon and letting air out while stretching the neck of the balloon. As the balloon neck is tightly stretched, high-pitched sounds are produced. When the neck is more relaxed, lower-pitched sounds occur. 4. Students often appreciate explanations that help them understand their own experiences. When we struggle with respiratory infections or allergies, especially when the air is dry, thick mucus accumulates in our branchial system. A long, warm shower hydrates these mucus films, facilitating their movement up and out of our -respiratory systems. Although students might have heard this advice, they might not have fully understood the mechanisms. (Sipping hot tea or soup also helps to hydrate these mucus surfaces.) \u00a9 2013 Pearson Education, Inc. 19.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}