1. Gas Exchange: Location and the Alveoli Nate Wardwell, Jessica DeFinis, and Thanh Pham

2. What are Alveoli? Little Sacs in Lungs Function: Location of Gas Exchange Lined with Pulmonary Capillaries MASSIVE surface area (75 m 2 ) Little Sacs in Lungs Function: Location of Gas Exchange Lined with Pulmonary Capillaries MASSIVE surface area (75 m 2 ) http://www.clevelandareaph.com/Lungs_and_alveoli.gif

3. How do Alveoli Work? (Basics) Inhale => O 2 into alveoli –=> into blood stream Exhale => CO 2 diffuses from capillaries into alveoli –=> out of body Inhale => O 2 into alveoli –=> into blood stream Exhale => CO 2 diffuses from capillaries into alveoli –=> out of body http://www.le.ac.uk/pathology/teach/va/anatomy/case2/frmst2.html

4. Inhalation Pressure Gradient: –High O 2 in Alveoli –Low O 2 in Capillaries O 2 can’t dissolve well in blood plasma –Hemoglobin= easy for O 2 to attach to –Becomes oxyhemoglobin (HbO 2 ) Pressure Gradient: –High O 2 in Alveoli –Low O 2 in Capillaries O 2 can’t dissolve well in blood plasma –Hemoglobin= easy for O 2 to attach to –Becomes oxyhemoglobin (HbO 2 ) http://z.about.com/f/p/440/graphics/images/en/19443.jpg

5. Exhalation CO 2 is largely carried in blood as HCO 3 - (60%) –30% on Hemoglobin (Carbamino hemoglobin) –10% Dissolved Is converted back to CO 2 in alveoli by red blood cells Pressure Gradient! –High CO 2 in Blood –Low CO 2 in Alveoli CO 2 is largely carried in blood as HCO 3 - (60%) –30% on Hemoglobin (Carbamino hemoglobin) –10% Dissolved Is converted back to CO 2 in alveoli by red blood cells Pressure Gradient! –High CO 2 in Blood –Low CO 2 in Alveoli http://www.emptynosesyndro me.org/pics/image007.gif

6. Summary Video http://www.youtube.com/watch?v=bwXv qSqAgKc http://www.youtube.com/watch?v=bwXv qSqAgKc

7. Bibliography Starr, Cecie, and Ralph Taggart. Biology: The Unity and Diversity of Life. 9th. United States of America: Brooks/Cole, 2001. "Bio 301: Human Psychology." Human Pyysiology-Respiration. 28 Oct 2008. Starr, Cecie, and Ralph Taggart. Biology: The Unity and Diversity of Life. 9th. United States of America: Brooks/Cole, 2001. "Bio 301: Human Psychology." Human Pyysiology-Respiration. 28 Oct 2008.