1. End Show Slide 1 of 37 Copyright Pearson Prentice Hall 37-3 The Respiratory System

2. End Show 37-3 The Respiratory System Slide 2 of 37 Copyright Pearson Prentice Hall What Is Respiration? In biology, respiration means two different things. 1. Cellular respiration = when cells release energy from the breakdown of food in the presence of oxygen. 2. respiration = the process of gas exchange (carbon dioxide out / oxygen in)

3. End Show 37-3 The Respiratory System Slide 3 of 37 Copyright Pearson Prentice Hall The Human Respiratory System The basic function of the human respiratory system is the exchange of oxygen and carbon dioxide between the blood, the air, and tissues. In addition, air entering the respiratory system is warmed, moistened, and filtered before it enters the lungs.

4. End Show 37-3 The Respiratory System Slide 4 of 37 Copyright Pearson Prentice Hall The Human Respiratory System The respiratory system consists of the: nose (& mouth) pharynx larynx trachea bronchi bronchioles alveoli of lungs

5. End Show 37-3 The Respiratory System Slide 5 of 37 Copyright Pearson Prentice Hall The Human Respiratory System Epiglottis Trachea Nose Pharynx Larynx Lungs Bronchus Mouth Diaphragm Bronchioles

6. End Show 37-3 The Respiratory System Slide 6 of 37 Copyright Pearson Prentice Hall The Human Respiratory System Air enters the nose or mouth and moves to the pharynx, or throat. The pharynx serves as a passageway for both air and food. Nose Pharynx

7. End Show 37-3 The Respiratory System Slide 7 of 37 Copyright Pearson Prentice Hall The Human Respiratory System Air moves from the pharynx into the trachea, or windpipe. The epiglottis covers the entrance to the trachea when you swallow. Epiglottis Trachea

8. End Show 37-3 The Respiratory System Slide 8 of 37 Copyright Pearson Prentice Hall The Human Respiratory System At the top of the trachea is the larynx, which contains two elastic folds of tissue called vocal cords. Larynx

9. End Show 37-3 The Respiratory System Slide 9 of 37 Copyright Pearson Prentice Hall The Human Respiratory System Air then passes through the trachea into two large passageways in the chest cavity called bronchi. Each bronchus leads into one of the lungs. Lungs Bronchus

10. End Show 37-3 The Respiratory System Slide 10 of 37 Copyright Pearson Prentice Hall The Human Respiratory System In each lung, the bronchus subdivides into smaller bronchi, and then into bronchioles. Bronchioles

11. End Show 37-3 The Respiratory System Slide 11 of 37 Copyright Pearson Prentice Hall The Human Respiratory System Bronchioles subdivide into millions of tiny air sacs called alveoli. Alveoli are grouped in grape-like clusters. Alveoli Bronchiole

12. End Show 37-3 The Respiratory System Slide 12 of 37 Copyright Pearson Prentice Hall The Human Respiratory System A network of capillaries surrounds each alveolus. Pulmonary vein Capillaries Pulmonary artery

13. End Show 37-3 The Respiratory System Slide 13 of 37 Copyright Pearson Prentice Hall Gas Exchange Gas exchange takes place in the alveoli. Oxygen diffuses into the blood. Carbon dioxide diffuses out of the blood. Capillary O2O2 CO 2

14. End Show 37-3 The Respiratory System Slide 14 of 37 Copyright Pearson Prentice Hall Breathing Breathing is the movement of air into and out of the lungs. The force that drives air into the lungs comes from air pressure.

15. End Show 37-3 The Respiratory System Slide 15 of 37 Copyright Pearson Prentice Hall Breathing During inhalation, the diaphragm contracts and the rib cage rises up. This expands the volume of the chest cavity, creating a vacuum. Atmospheric pressure fills the lungs as air rushes into the breathing passages.

16. End Show 37-3 The Respiratory System Slide 16 of 37 Copyright Pearson Prentice Hall Breathing Often exhaling is a passive event. The rib cage lowers & the diaphragm relaxes, pushing air out of the lungs. Exhalation Rib cage lowers Air Exhaled

17. End Show Slide 17 of 37 Copyright Pearson Prentice Hall 37-3 Air passes through the trachea into two large passageways in the chest cavity known as the a.bronchi. b.alveoli. c.epiglottis. d.bronchioles.

18. End Show Slide 18 of 37 Copyright Pearson Prentice Hall 37-3 The function of the cilia lining the respiratory surfaces is to a.improve the amount of oxygen and carbon dioxide exchanged in the lungs. b.cover the opening of the trachea when you swallow. c.move air in and out of the lungs. d.sweep trapped particles and mucus away from the lungs.

19. End Show Slide 19 of 37 Copyright Pearson Prentice Hall 37-3 Oxygen diffuses from the alveolus into the blood because a.blood entering the capillaries of the lungs is oxygen-poor. b.blood entering the capillaries of the lungs is oxygen-rich. c.air entering the lungs has more carbon dioxide than oxygen. d.air entering the lungs has less oxygen than is found in the blood.