14.3 lecture 2019
- 1. Section 3: The Respiratory System What are the functions of the respiratory system? What structures does air pass through as it travels to the lungs? What happens during gas exchange and breathing? • 7.5.a Students know plants and animals have levels of organization for structure and function, including cells, tissues, organs, organ systems, and the whole organisms. • 7.5.b Students know organ systems function because of the contributions of individual organs, tissues, and cells. The failure of any part can affect the entire system.
- 2. Respiratory System Functions • Your body cells need oxygen and they get it from the air you breathe. • The respiratory system moves oxygen from the outside environment into the body. • It also removes carbon dioxide and water from the body.
- 3. Taking in Oxygen • Like a fire: Your cells cannot “burn” the “fuel” that you eat without oxygen. • Respiration = the process by which cells break down simple food molecules such as glucose to release the energy they contain – AKA cellular respiration – Respiration ≠ Breathing
- 4. Removing Carbon Dioxide and Water • Released through lungs
- 5. The Air You Breathe The air you breathe in contains several different gases, shown in the circle graph on the left. The air you breathe out contains the same gases, but in the amounts shown in the circle graph on the right.
- 6. The Air You Breathe Percent of a gas breathed in or out •Reading Graphs: What does each wedge of the graphs represent?
- 7. The Air You Breathe Oxygen; less oxygen is breathed out than breathed in—meaning that some must have been used by the body. •Interpreting Data: Based on the data, which gas is used by the body? Explain.
- 8. The Air You Breathe There is a higher percentage of carbon dioxide in exhaled air. Carbon dioxide is a waste product of cellular activity. •Drawing Conclusions: Compare the percentage of carbon dioxide in inhaled air with the percentage in exhaled air. How can you account for the difference?
- 9. The Air You Breathe Nitrogen is not used by the body and is not a waste product. –Inferring: Explain why the percentage of nitrogen is the same in both inhaled air and exhaled air.
- 10. Systems Working Together Oxygen from the air and glucose from digested food are both carried to the cells by the blood. During respiration, oxygen reacts with glucose to release energy.
- 11. Path of Air • Particles in the air must be filtered out. • As air travels from the outside environment to the lungs, it passes through the following structures: nose, pharynx, trachea, and bronchia. • Air is also warmed and moistened.
- 13. The Nose (1) • Air enters into the body through the nose and then into nasal cavities. Some of the cells lining the nasal cavities produce mucus. • Mucus = A thick, sticky liquid produced by the body. – moistens the air, keeps lining from drying out, traps particles • Cilia = The hairlike projections on the outside of cells that move in wavelike manner. – Swept into your stomach. • Sneeze
- 14. The Pharynx (2) • Pharynx = The throat. • Both the nose and the mouth connect to the pharynx. • Shared with digestive system.
- 15. WHAT IS THE ROLE OF CILIA? Reading Checkpoint
- 16. The Trachea (3) • Trachea = The windpipe; a passage which air moves in the respiratory system. • Continue cleaning and moistening of air. – Cough – Choking • Epiglottis - seals off the trachea during swallowing
- 17. The Bronchi (4) and Lungs (5) • Bronchi = The passages that direct air into the lungs. • Lungs = An organ found in air-breathing vertebrates that exchanges oxygen and carbon dioxide with the blood. • Alveoli = Tiny sacs of lung tissue specialized for the movement of gases between air and blood. – surrounded by capillaries – blood picks up oxygen from the air
- 18. HOW IS FOOD PREVENTED FROM ENTERING THE TRACHEA? Reading Checkpoint
- 20. Gas Exchange • The walls of both the alveoli and the capillaries are very thin! • After air enters an alveolus, oxygen passes though the wall of the alveolus and then through the capillary wall into the blood. • Carbon dioxide and water pass from the blood into the alveoli. • This whole process is known as gas exchange.
- 21. How Gas Exchange Occurs • Circulatory and respiratory systems work together • Pulmonary circulation – carries blood from the heart to the lungs and back After air enters an alveolus, oxygen passes through the wall of the alveolus and then through the capillary wall into the blood. Carbon dioxide and water pass from the blood into the alveoli.
- 23. Surface Area For Gas Exchange • 300 million alveoli, 70 square meters
- 24. WHAT GASES ARE EXCHANGED ACROSS THE ALVEOLI? Reading Checkpoint
- 25. Surface Area Surface area refers to the total area of all the surfaces of a three- dimensional object. Consider a cube, which has six equal sides. Each side measures 2 cm by 2 cm. 1. To find the surface area of the cube, first calculate the area of one of the six sides: Area = length x width = 2 cm x 2 cm = 4 cm2 Each side has an area of 4 cm2. 2. Then, add the areas of the six sides together: 4 cm2 + 4 cm2 + 4 cm2 + 4 cm2 + 4 cm2 + 4 cm2 = 24 cm2 The surface area of the cube is 24 cm2.
- 26. How You Breathe When you breathe, the actions of your rib muscles and diaphragm expand or contract your chest. As a result, air flows in or out. The more oxygen you need, the faster you breathe.
- 27. Muscle for Breathing • Diaphragm = A large muscle located at the bottom of a mammal’s rib cage that functions in breathing.
- 28. The Process of Breathing • When you breathe, the actions of your rib muscles and diaphragm cause your chest to expand or contact. • As a result, air flows in or out. • Vacuum – causes air to rush into your lungs
- 29. WHAT MUSCLES CAUSE THE CHEST TO EXPAND DURING BREATHING? Reading Checkpoint
- 30. Relating Breathing and Speaking • Larynx = The voice box. • Vocal chords = Folds of connective tissue that stretch across the opening of the larynx and produce a persons voice. • Air moving over the vocal cords causes them to vibrate and produce sound.