2. Respiratory System Function??????

3. Lung Exchange of gases with body cells Cell Capillary Mitochondria Breathing Circulatory system Transport of gases by the circulatory system CO 2 O2O2 O2O2 1 2 3

4. Cut CO 2 O2O2 Cross section of respiratory surface (the outer skin) Capillaries

5. Specialized organs used for gas exchange –Gills in fish and amphibians –Tracheal systems in arthropods –Lungs in tetrapods that live on land –Amphibians –Reptiles –Birds –Mammals

6. Copyright © 2009 Pearson Education, Inc. Gills –Increase the surface area for gas exchange –Oxygen absorbed –Carbon dioxide released - gas exchange is enhanced by –Ventilation of the gills (moving water past the gills) –Countercurrent flow of water and blood

7. Gill arch Direction of water flow Operculum (gill cover) Gill arch Blood vessels Oxygen-rich blood Oxygen-poor blood Lamella Gill filaments Water flow between lamellae Blood flow through capillaries in lamella Countercurrent exchange Blood flow in simplified capillary, showing % O 2 Diffusion of O 2 from water to blood Water flow, showing % O 2 100 70 4015 5 30 6080

8. Gill arch Direction of water flow Operculum (gill cover) Gill arch Blood vessels Oxygen-rich blood Oxygen-poor blood Lamella Gill filaments Water flow between lamellae Blood flow through capillaries in lamella Countercurrent exchange Blood flow in simplified capillary, showing % O 2 Diffusion of O 2 from water to blood Water flow, showing % O 2 100 70 4015 5 30 6080 Gill arch Direction of water flow Operculum (gill cover) Gill arch Blood vessels Gill filaments

9. Gill arch Blood vessels Oxygen-rich blood Oxygen-poor blood Lamella Gill filaments Water flow between lamellae Blood flow through capillaries in lamella Countercurrent exchange Blood flow in simplified capillary, showing % O 2 Diffusion of O 2 from water to blood Water flow, showing % O 2 100 704015 5 30 6080

10. Human Respiratory System

11. Trachea – Cilia Bronchi Cartilage Alveoli Capillaries Nasal cavity larynx

12. 1 5 4 3 2 8 7 6 9

13. Alveoli CO 2 O2O2 CO 2 -rich, O 2 -poor blood O 2 -rich, CO 2 -poor blood Exhaled air Inhaled air Air spaces Alveolar capillaries Tissue capillaries Tissue cells throughout body Heart CO 2 O2O2 O2O2 O2O2 Exchange of gases in the alveoli and the tissue cells

15. Artery from the heart Vein going to heart bronchiole alveoli capillary air space

16. Lung Diaphragm contracts (moves down) Diaphragm Inhalation Air inhaled Rib cage expands as rib muscles contract Volume in thoracic cavity goes up Pressure goes down Low pressure inside, higher outside air rushes in

17. Diaphragm relaxes (moves up) Air exhaled Rib cage gets smaller as rib muscles relax Exhalation Volume in thoracic cavity goes down Pressure goes up higher pressure inside, lower outside air rushes out

18. Fig. 22-11 How are the gases carried in the blood? Oxygen?Carbon dioxide? Most is converted into bicarbonate ions and transported in the blood plasma CO 2 + H 2 O H 2 CO 3 H + + HCO 3 -