Oxygen is non polar gas how blood carried oxygen which is composed of 92% water
Answers
Answer:
Some general comments about gas exchange and diffusion will be made, followed by a description of how oxygen is carried in the blood. The binding of oxygen to hemoglobin will be discussed, including the oxygen saturation (or dissociation) curve and factors (allosteric effectors) which cause it to shift. Next, a discussion of the effects of carbon monoxide on oxygen binding will be presented. Finally, a description of artificial oxygen carriers will be presented. Most of these topics are covered in standard textbooks [6,10,54,113] and monographs on oxygen transport [112].
GAS EXCHANGE AND DIFFUSION
Overall Gas Exchange
Table 2 gives the partial pressures of the four respiratory gases in dry air, moist tracheal air, alveoli and arterial and venous blood.
Table 2. Partial pressures of gases in gas and blood phases.
Table 2
Partial pressures of gases in gas and blood phases.
The composition of alveolar gas depends upon the composition of inspired gas, composition of gas in the functional residual capacity (FRC), minus the O2 taken up by the blood plus the CO2 added from blood. Details of how the listed composition arises are discussed in standard monographs of respiratory physiology on the topic of ventilation/perfusion defects [6,10,54,113].
Diffusion
Diffusion takes place in the gas phase by the random motion of gas molecules.
Graham's law of diffusion (1833) states that the rate of diffusion of a gas is inversely proportional to the square root of its molecular weight (D∼MW−½). Thus, the relative rates of diffusion of CO2 and O2 are equal to √(32/44) or 0.85. Diffusion coefficients in the gas phase are Dgas ≈ 10−1 cm2/sec. In the liquid phase, diffusion rates of gases are generally 10,000 times smaller than those in gaseous environments due to the much shorter mean free path between collisions with other molecules (e.g., the solvent); thus, Dliquid ≈ 10−5 cm2/s [55]. This is not a severe handicap, however, since the distances over which gas transfer must take place in the liquid phase are generally short (about 100 times shorter than that in the gas phase).
Fick's Law of Diffusion
Fick's first law states that the amount of gas transferred per unit time (ΔN/Δt) across a membrane of thickness Δx is proportional to the area (A) available for exchange and the partial pressure difference (ΔP) of the gas across the membrane. The constant of proportionality (K) is called Krogh's diffusion coefficient (see below) to distinguish it from D: