Interactive Physiology

The Respiratory System: Gas Transport

1. Oxygen transport in the blood:

_98.5____% is bound to hemoglobin

_1.5____% dissolves in plasma

2. The hemoglobin molecule is composed of _4__ polypeptide chains and _4__ heme groups containing iron.

What does oxygen bind to? ___hemoglobin______

3. After one oxygen molecule (O2) binds to hemoglobin, it is easier for the other molecules to bind to the hemoglobin.

This is known as ____?_______________.

4. When oxygen is loaded onto hemoglobin in the lungs, hemoglobin is called __oxyhemoglobin_______________, and when oxygen is unloaded from the hemoglobin at the tissues it is called __deoxyhemoglobin__________________.

5. From the oxygen-hemoglobin dissociation curve, we see the following:

Lungs: Partial pressure of oxygen is _100___ mmHg

Hemoglobin is _98___% saturated

Tissues: Partial pressure of oxygen is 40___ mmHg

Hemoglobin is _75___% saturated

6. Effect of high altitude on lung PO2: 80mm Hg, hemoglobin 95% saturated

With a decrease of 20 mmHg in the lungs, will the saturation of hemoglobin decrease significantly? ____no_________

7. Effect of exercise on tissue PO2: lowers Po2 (20mm Hg)

With a decrease of 20 mmHg in the tissues, will the saturation of hemoglobin decrease significantly? _no_____.

How does this help the tissues? ____it releases much more oxygen to the tissues_________________________.

8. Name the other factors that alter PO2: pH, temperature, Pco2, and BPG

During exercise,