Respiratory System PDF

3.6 The Respiratory Inhale…Exhale… System Functions On average, you breathe in and out 15 times each minute to move more than 10 000 L of air in and out of the lungs each day Rate increases if level of physical activity increases Provides oxygen to the body and removes carbon dio...

3.6 The Respiratory Inhale…Exhale… System Functions On average, you breathe in and out 15 times each minute to move more than 10 000 L of air in and out of the lungs each day Rate increases if level of physical activity increases Provides oxygen to the body and removes carbon dioxide (produced as your body uses energy for growth, repair, and movement) = GAS EXCHANGE Works closely with the circulatory system to transport these substances Components The respiratory system is made up of the following: Nasal cavity Mouth Pharynx Trachea Bronchi (singular: bronchus) Lungs Diaphragm Respiratory System Diagram – Parts: Nasal cavity Mouth Pharynx Trachea Lungs Bronchi (2) Bronchioles Diaphragm Alveoli Pathway of Air Mouth/Nose  Pharynx (Throat)  Trachea (Windpipe)  Bronchi  Lungs Inside lungs: bronchioles  alveoli  Cilia Trachea Also known as the “windpipe” Supported by cartilage rings made up of a special type of connective tissue that is strong but flexible Keeps trachea open and allows air to flow freely Contains epithelial cells that produce mucus (like in digestive tract) as well as epithelial cells that have hair-like projections called cilia Cilia help move mucus and filter out debris (remove foreign materials such as dust) that can enter the bronchial tubes and lungs Bronchi and Bronchioles Trachea branches into two bronchi (singular: bronchus) —one goes to each lung Bronchus Epithelial cells lining the bronchi produce mucus and Bronchioles have cilia to help filter air Inside the lungs, bronchi branch again and again to form bronchioles Alveoli Singular: alveolus Are tiny air sacs found at the ends of bronchioles Each alveolus has very thin walls and is Bronchiole surrounded by a capillary network (blood vessels) allowing gas exchange to occur efficiently Alveolus Capillary Oxygen diffuses from the alveoli into the blood Alveolar sac Carbon dioxide diffuses from the blood into the alveoli Alveoli Alveoli: Gas Exchange The circulatory system provides a blood supply to lungs The concentration of oxygen in blood at the lungs is less than the concentration of oxygen in air at the alveoli So oxygen always diffuses into the blood Oxygen is carried by blood to other parts of the body Oxygen diffuses out of the blood and into the cells Excess carbon dioxide diffuses from cells into the blood Carbon dioxide is then carried by the blood to the lungs, where it diffuses into the air in the alveoli to be expelled Diaphragm Thin dome-shaped muscular sheet that lies underneath ribs Dome-shaped when relaxed, flattens when contracted Breathing Involuntary reaction—you DO NOT have to think about it, it just happens! You can override it (hold your breath) but only temporarily Controlled by a part of the brain that detects the concentration of carbon dioxide in the blood Brain sends signals to diaphragm, rib muscles, heart Increased carbon dioxide levels in the blood causes an increase in breathing rate and heart rate Inhalation Taking air INTO lungs INHALATION Diaphragm Contracts (flattens) Intercostal Muscles (Rib muscles) Contracts Chest cavity Up and Out Volume Increases Pressure Decreases Air moves... In Exhalation Pushing air OUT of lungs EXHALATION Diaphragm Relaxes (dome-shape) Intercostal Muscles (Rib muscles) Relaxes Chest cavity In and down Volume Decreases Pressure Increases Air moves... Out Video: What do the lungs do? Diseases of the Respiratory System: Tuberculosis (TB) Infectious disease easily passed between people Caused by bacteria that enter your body when you breathe Bacteria grows in lungs, but can spread to nervous system and bones Bacteria can remain dormant (inactive) for years Fatal if left untreated Symptoms: fever, cough, weight loss, tiredness, chest pain Diagnosis: chest X-ray AND examining stomach/lung samples Treatment: medicine, hospitalization Diseases of the Respiratory System: Lung Cancer Tobacco smoke, both first-hand and second- hand, is a serious threat to the health of the respiratory system Tobacco smoke contains many known carcinogens which also contribute to cancers of the mouth, esophagus, larynx, pancreas, and bladder The Respiratory System in Other Animals: Fish All respiratory systems depend on the process of DIFFUSION to move oxygen in, and carbon dioxide out In fish, the gas exchange organs are the gills, which are in close contact with water Gills are have many capillaries (like lungs) that bring blood close to the water Oxygen diffuses from the water into the blood, while carbon dioxide diffuses from the blood into the water HOMEWORK: Read pg. 91-95 in textbook; do Q: #2-4 (pg. 95) ANSWERS Q: # 2-4 (pg. 95) 2. The role of epithelial tissue in the trachea and bronchi is to secrete mucus to filter out foreign material. 3. The circulatory system carries oxygen and carbon dioxide that are exchanged by the respiratory system. 4. Breathing is the intake and output of air. Gas exchange involves the diffusion of oxygen into the blood and carbon dioxide out of the blood.