pH and gas exchange
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!
Vessels to know
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
Bicarbonate Buffer System Acid base homeostatic mechanism 𝐻 2 𝑂+ 𝐶𝑂 2 ↔ 𝐻 2 𝐶𝑂 3 ↔ 𝐻𝐶𝑂 3 − + 𝐻 + Hydration, dehydration reaction
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
What is in blood? Connective tissue Blood plasma (~55%) RBCs (erythrocytes), WBCs (leukocytes), & blood platelets (thrombocytes)
Red Blood Cells No nucleus Hemoglobin (Red) Globin protein Heme Transports oxygen
White Blood Cells Larger than RBCs Nucleus Translucent Fight infection Phagocytic or antibodies
Platelets Not complete cells Plugs that seal damaged vessels
Hemoglobin
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
Keeping up with the Joneses
Data from Suzie’s physical
Data from Suzie’s physical