Respiratory System

1. Respiratory System Anatomy of the Human Body

2. Respiratory System • Respiration – how energy stored in the nutrients is chemically released for use in the body • Respiratory system – transports gases between the external environment and the internal surfaces where gas exchange occurs • Consist of series of passage ways through which air from the external and internal environment where gas exchange in the lungs take place • Three types of Respiration : • External Respiration – occurs outside the cells and involves the exchange of gases between the lungs and the blood • Internal Respiration – takes place when gases are exchanged between the blood and the body cells • Cellular Respiration – an energy-releasing process that takes place inside the cells

3. Steps of the Respiration System Air enters through the nostrilsand mouth, moving through hollow cavities called nasal passagesin the throat Nasal passages are covered with cilia , which are mucous membranes that moisten, warm and filter air Air passes into the back of the throat (pharynx) Located in the pharynx is the glottis (opening the windpipe), where the epiglottis (a flap of skin) covers the glottis during swallowing to prevent food entering the pharynx The trachea (windpipe) transports air to the bronchial tubes. Trachea divides into two bronchial tubes called bronchi

4. Steps of the Respiratory System The bronchi further branches into smaller tubes called bronchioles The bronchioles end in air sacs in two lungs located in the left and right of the chest cavity. Right lung is composed of 3 lobes and the left lung is composed of 2 lobes. Each lung is covered by the pleural membrane that secretes moisture that allows the lungs to move smoothly. Gas exchange takes place at the alveoli, most thin membranes surrounded by a network of blood capillaries. All organisms must have a moist, thin membrane for gas exchange to occur. As blood passes through the capillaries oxygen is absorbed by the blood stream from the alveoli and respiratory wastes are released from the blood stream and into the alveoli and then travels out of the body.

6. Gas exchange at alveoli

7. Breathing • Breathing – movement of respiratory gases between the outside environment and the lungs by the process of inhalation and exhalation • Inhalation – movement of air into the lungs • Exhalation – movement of air out of the lungs • Lungs have no muscle tissue so the body must use differences in air pressure between the chest cavity and outside environment • Most important factor in controlling breathing rate is the concentration of carbon dioxide in the blood. • Increase CO2 in blood = Increases breathing rate • Decrease CO2in blood = Decreases breathing rate

8. Breathing Diaphragm – a dome-shaped muscle located at the bottom of the chest cavity During inhalation, the diaphragm moves down and the rib muscles move upward and outward to enlarge the chest cavity, forcing air into the lungs During exhalation, the diaphragm moves up to its original curved position (up) and ribs move in, making the chest cavity smaller and forcing air out of the lungs

10. Diseases of the Respiratory System Bronchitis – an inflammation of the lining of the bronchial tubes causing the bronchioles to secrete too much mucus and becoming small and irritated Asthma – bronchial tubes narrow preventing oxygen from entering lungs causing a feeling of suffocation Emphysema – lung disease in which alveoli become large and break down. Lungs become less elastic and decrease in the amount of air that can be held causing shortness of breath Pneumonia – infection of lungs. Alveoli become filled with fluid preventing proper gas exchange Lung Cancer – uncontrollable growth of tumors in lungs. Proven relationship between lung cancer and cigarette smoking.

11. Respiratory System The Respiratory System - http://www.youtube.com/watch?v=hc1YtXc_84A Breathing - http://www.youtube.com/watch?v=gYSIWceGMxY Bill Nye the Science Guy Respiration - http://www.youtube.com/watch?v=SEngwEhhv8I