Biology 105
Biology of Exercise
Spring 2003
4/2/03 - Post-class outline
Learning objectives:
How do we get oxygen to the exercising tissues?
Diagrams
Why do we need circulatory and respiratory systems?
Steps in the process
- Ventilation - oxygen moves into the lungs.
- Pulmonary gas exchange - oxygen diffuses into the blood.
- Hemoglobin - oxygen binds to hemoglobin and is carried to the tissues where
it is released from hemoglobin.
- Tissue gas exchange - oxygen diffuses into the tissues where it is used
in aerobic metabolism.
Convection vs. diffusion.
Ventilation
- Boyle's law - at a constant temperature, Pressure * Volume = Constant. Or
P~(1/V). So, as volume increases, pressure decreases.
- Relationship of lung to chest cavity.
- Size of chest cavity increases during inspiration.
Pulmonary gas exchange
- Gases diffuse along partial pressure gradients
- In Air:
- P barometric = 760 mmHg (100%)
- P oxygen = 160 mmHg (21%)
- P carbon dioxide = 0.3 mmHg (0.04%)
- P nitrogen = 600 mmHg (79%)
- In venous blood
- P oxygen = 40 mmHg
- P carbon dioxide = 45 mmHg
- In arterial blood
- P oxygen = 100 mmHg
- P carbon dioxide = 40 mmHg
- Oxygen diffusion in alveoli
- Carbon dioxide diffusion in alveoli
