1. Respiration – external and internal

2. External Respiration

3. How does oxygen move into the blood? O 2 is in high concentration in the alveoli and low in the capillaries. The partial pressure of O 2 in the lungs is greater than the partial pressure of O 2 in the blood. (P O 2 ) O 2 diffuses into the plasma and then diffuses into the red blood cells. O 2 combines with hemoglobin in the rbc to form oxyhemoglobin. Hb + O 2 HbO 2

4. How does carbon dioxide leave the blood stream? Blood in the pulmonary capillaries has a higher partial pressure of CO 2, (P CO 2 ) than the air in the lungs. CO 2 diffuses out of the plasma into the alveoli. CO 2 travels 3 ways in the blood stream. 1. freely as dissolved CO 2 2. combined with hemoglobin as carbaminohemoglobin Hb + CO 2 HbCO 2 3. bicarbonate ions, HCO 3 - (The above are arranged from the least amount to the most.)

5. The Release of CO 2 from HCO 3 - As CO 2 diffuses out of the plasma at the alveoli, the following reaction is driven to the right. H + + HCO 3 - H 2 CO 3 H 2 O + CO 2 Hydrogen ions + bicarbonate ions (carbonic anhydrase) carbonic acid (carbonic anhydrase) water + carbon dioxide What is carbonic anhydrase? Where does this reaction take place?

6. Where did the Hydrogen Ions come from? H + will increase the pH of the blood and acidosis will occur if the blood is not BUFFERED. Hemoglobin acts as a buffer in the blood by combining with the H +. Hb + H + HHb Hemoglobin + hydrogen ions reduced hemoglobin Bicarbonate ions act as buffers also.

8. Recap Explain the transport of oxygen from the atmosphere to the cells in the body. Explain the transport of carbon dioxide from the cells in the body to the atmosphere. Name 4 forms of hemoglobin List 3 methods of carbon dioxide transport in the plasma of the blood. Name 2 buffers in the plasma.

10. Hemoglobin Name the 4 forms of hemoglobin and what is being carried. Deoxyhemoglobin - Hb Oxyhemoglobin – HbO 2 Carbaminohemoglobin – HbCO 2 Reduced hemoglobin - HHb

11. Carbon Dioxide Transport