The Respiratory System Chapter 17 Lesson 3

Function of the Respiratory System Respiration (the exchange of gases between your body and your environment). 2 parts: External respiration: exchange of oxygen and carbon dioxide between the blood and air in the lungs. Internal respiration: exchange of gases between the blood and cells of the body.

Structure of the Respiratory System Lungs Nose Mouth These are supported by the diaphragm (a muscle that separates the chest and abdominal cavities). Without the diaphragm, respiration would be impossible.

Lungs Principal organ of your respiratory system. Take in oxygen from the air you inhale and return carbon dioxide (c02) to the air when you exhale. Lungs get their power from the diaphragm.

The Breathing Process When you inhale, the rib muscles and diaphragm contract. Diaphragm moves downward and ribs pulled up and out. This movement enlarges the chest cavity, creating lower pressure in the lungs. Air rushes into the lungs to equalize the pressure between the lungs and outside environment. The reverse happens when you exhale (diaphragm relaxes, moving upward, and the ribs move inward, increasing pressure within the lungs. Video

Structure of the Lungs Each lung is divided into sections called lobes. 3 lobes in the right lung & 2 in the left. The airways that lead into the lungs divide to form a network called bronchioles. At the end of each bronchiole is a cluster of thin-walled air sacs called alveoli. These alveoli are covered with a lots of capillaries. It is these alveoli where the exchange of air and carbon dioxide take place.

Other Respiratory Structures There are two points of entry for air to get to your lungs: Nose & Mouth Breathing through the nose has an advantage in that it is filtered and cleaned by mucous membranes and tiny hairs called cilia. From your nose, air moves through the pharynx (throat) and into the trachea (windpipe). The trachea is also lined with mucous membranes and cilia. These are the 2nd line of defense to trap foreign particles and keep them from entering your lungs. Air completes its journey to the lungs through the bronchi (the airways that connect the trachea to the lungs).

Larynx & Epiglottis On its journey to the lungs, air passes over two structures that are not directly related to inspiration (when oxygen is taken in) – but are very important. Larynx (voice box) Contains vocal cords. As air passes over these cords, the cords vibrate and produce sound. Without them, speech is not possible. Epiglottis (flap of cartilage in front of the entrance to the larynx). At rest, the epiglottis is open to allow air to pass into the lungs. When you swallow, it closes to prevent food and liquid from being inhaled. “Went down the wrong pipe” Epiglottis failed to close properly, allowing food or drink to enter your trachea.

Care of the Respiratory System Respiratory System (RS) is highly susceptible to infection from both bacteria and viruses. Avoid putting your hands up to your nose or mouth – as your hands are a carrier of disease organisms. It is vital to develop an awareness of this habit and do it less. Wash your hands! Avoid pollutants such as tobacco smoke. Exercise regularly! This helps to keep your lungs working efficiently.

Respiratory System Problems Bronchitis Asthma Pneumonia Tuberculosis Emphysema Sinusitis

Bronchitis Inflammation of the bronchi. Symptoms: wheezing, shortness of breath, and coughing. Can be acute or chronic. Both types are common in smokers and areas of high pollution. Acute bronchitis comes on suddenly and usually clears up quickly. It is usually a complication of a viral infection such as cold or flu. Chronic bronchitis is longer-lasting, and recurring. Most important in the treatment of chronic bronchitis is avoiding respiratory irritants such as cigarette smoke, dust, fumes, and other air pollutants.

Asthma Is an inflammatory condition in which the small airways in the lungs called bronchioles become narrowed, causing difficulty breathing. The mucous lining swells and secretions build up, making breathing more difficult. Can be triggered by exertion, emotion, infection, allergies, weather. 1 in 20 people (1 in 10 children) are asthmatic. Treatment: bronchodilators – medicine that relaxes and widens airways. Most people administer the medication themselves.

Pneumonia Pneumonia is inflammation of the lungs. Not a single disease but the name for several types of lung inflammation caused by bacteria or viruses. 2 main types: Lobar pneumonia One lobe of the lung is affected at first. Bronchial pneumonia Inflammation starts in the bronchi and then spreads to lungs Symptoms: fever, chills, shortness of breath, sever cough. Chest pain that is worse when breathing may occur because of pleurisy (inflammation of the membrane lining of the lungs and chest cavity).

Tuberculosis Infectious bacterial disease of the lungs. Symptoms: fever, sweating, weakness, poor appetite, shortness of breath, sever coughing. Pretty care in developed countries (such as U.S.) because on modern antibiotic medicines/immunizations.

Emphysema Disease in which the alveoli in the lungs burst and blend to form fewer, larger sacs with less surface area. As a result, normal exchange of carbon dioxide and oxygen in alveoli is disrupted. Symptoms: difficulty breathing, chronic cough. Cause: breathing in foreign matter such as smoke, and other air pollutant over a long period of time. In almost all cases it is caused by cigarette smoking. The condition cannot be reversed.

Sinusitis Sinusitis is an inflammation of the membrane lining the facial sinuses, the air-filled cavities in the bones that surround the nose. Cause: infection that spreads to the sinuses from the nose. Symptoms: fever, stuffy nose, ache in affected area Treatment: antibiotics, decongestant drops/spray, or steam inhalation