1. Gas Exchange Ana Zarate <3

3. 6.4.1 Distinguish between ventilation, gas exchange, and cell respiration  Ventilation is the movement in and out of the lungs.  Gas exchange is the diffusion of O2 across the surface of the alveoli and through the capillaries, then into the erythrocytes.  Note that CO2 is mostly carried dissolved in the plasma itself and is moving out of the blood into the lungs at the same time O2 is diffusing the other way.  Cell respiration is then individual cells metabolize macromolecules in the presence if O2, releasing CO2 in the process, The gases diffuse into and out if the cells and into or out of the mitochondria.  Ventilation is the movement in and out of the lungs.  Gas exchange is the diffusion of O2 across the surface of the alveoli and through the capillaries, then into the erythrocytes.  Note that CO2 is mostly carried dissolved in the plasma itself and is moving out of the blood into the lungs at the same time O2 is diffusing the other way.  Cell respiration is then individual cells metabolize macromolecules in the presence if O2, releasing CO2 in the process, The gases diffuse into and out if the cells and into or out of the mitochondria.

5. 6.4.2 Explain the need for a ventilation system  A ventilation system is needed to maintain high concentration gradients in the alveoli

7. 6.4.3 Describe the features of alveoli that adapt them to gas exchange  Large total surface area  Wall consisting of a single layer of flattened cells  Film of moisture  Dense layer of capillaries  Large total surface area  Wall consisting of a single layer of flattened cells  Film of moisture  Dense layer of capillaries

8. 6.4.4 Draw and label a diagram of the ventilation system including trachea, lungs, bronchi, bronchioles, and alveoli

10. 6.4.5 Explain the mechanism of ventilation of the lungs…  A mammal breathes by changing the air pressure within its lungs relative to the pressure of the outside atmosphere. During inhalation, the rib muscles and diaphragm contract. The volume of the thoracic cavity and lungs increases as the diaphragm moves down and the rib cage expands. Air pressure in the lungs falls below that of the atmosphere, and air rushes into the lungs. Exhalation occurs when the rib muscles and diaphragm relax, storing the thoracic cavity to its smaller volume. (Campbell book p. 891- diagram)

12. Vocabulary  Gas exchange  Ventilation  Cell Respiration  Inhalation  Exhalation  Lungs  Alveoli  Capillaries  Trachea  Bronchi  Gas exchange  Ventilation  Cell Respiration  Inhalation  Exhalation  Lungs  Alveoli  Capillaries  Trachea  Bronchi

13. Images from: http://www.thehumanbody.ecsd.net/student_gallery.htm