1. pH and gas exchange

2. Fact of the Day The circulatory system is extremely long
If you were to lay out all of the arteries, capillaries and veins in one adult, end-to-end, they would stretch ~100,000 kilometers.
Capillaries would make up about 80 percent of this length.
Earth circumference = ~40,000 km. That means a person's blood vessels could wrap around the planet approximately 2.5 times!

3. Vessels to know

4. pH and Blood Chemoreceptors: monitor chemicals
Located in carotid arteries and aorta
Low pH stimulates increased breathing rate
Hematocrit: ratio of the volume of RBC to total blood volume

5. Bicarbonate Buffer System
Acid base homeostatic mechanism
𝐻 2 𝑂+ 𝐶𝑂 2 ↔ 𝐻 2 𝐶𝑂 3 ↔ 𝐻𝐶𝑂 3 − + 𝐻 +
Hydration, dehydration reaction

6. Gas Exchange – External Respiration
Partial pressure: PO2 & PCO2
Blood into the lungs:
H+ + HCO3-  H2CO3  H20 + CO2 (increase)
Carbonic anhydrase: enzyme present in red blood cells
Hemoglobin: respiratory pigment
Releases a hydrogen ion  deoxyhemoglobin
Hb + O2  HbO2

7. What is in blood? Connective tissue Blood plasma (~55%)
RBCs (erythrocytes), WBCs (leukocytes), & blood platelets (thrombocytes)

9. Red Blood Cells No nucleus Hemoglobin (Red) Globin protein Heme
Transports oxygen

10. White Blood Cells Larger than RBCs Nucleus Translucent Fight infection
Phagocytic or antibodies

11. Platelets
Not complete cells
Plugs that seal damaged vessels

12. Hemoglobin

13. Gas Exchange – Internal Respiration
Diffusion of O2 from high concentration to low
O2  plasma  RBCs in lungs  Oxyhemoglobin
HbO2  Hb + O2
Diffusion into tissues  cellular respiration

15. Keeping up with the Joneses

16. Data from Suzie’s physical

17. Data from Suzie’s physical