Normal Hb Levels

Hypoxia: Killer deadly

History of oxygen:

Colorless, odorless diatomic gas discovered by Priestley in 1771, which is manufactured by fractional distillation of air. 21% of the volume of atmospheric air is occupied by oxygen. Other gases are:

Atmospheric air

¨ 78.00% nitrogen

¨ 21.00% Oxygen

¨ Co2 0.03%

¨ Other 0.97%

Despite some dark places of oxygen is essential for cellular respiration. This oxygen is transported from air to the mitochondria of the cell through the series of measures by changing its partial pressure. This gradual change of the partial pressure of oxygen in mitochondria that was cascaded oxygen.

Cascade oxygen.

Partial pressure at different levels mm Hg

In dry atmospheric gases (PIO2) 160

Humidified alveolar (PaO 2) 106

1. Po2 in venous end of Pul. Hair 100

Systemic artery (PaO2) 95

PO2 in the ISS 40

Po2 in the cell 23

Reducing the partial pressure of oxygen in the cascade can lead to a marked reduction in the partial pressure in the mitochondria and the pressure falls below a critical threshold anaerobic metabolism occurs in the body. This critical mitochondrial PO2 was appointed as pastor Point. It is about 0.15 to 0.3 kPa

Oxygen transport

Oxygen is transported in the blood of two ways:

1. Dissolved form, which represents 3% of the total volume of oxygen and
2. In combination with Hb is about 97% of the total volume of oxygen

Dissolved in plasma (3%)

0.003 ml / mm Hg / dl blood

state dissolved oxygen in the blood is determined by Henry's law. Approximately 0.3 ml of oxygen dissolved in 100 ml of blood is 95 mm Hg

He is responsible for the PO2 in the blood.

In combination with Hb (97%)

1. Approximately 1.34 ml of O2 can be combined with 1 g of Hb at 100 mm Hg at 37 ° C

• arterial blood contains about 19.8 ml of blood O2/dl
• venous blood contains about 15.2 ml of blood O2/dl

Thus, under normal condition tissue eliminates an average of 5 ml O2 dl blood. Therefore, the body consumes an average of 250 ml per min O2.

Our body works in a very low oxygen environment and it will take about 3-4 minutes to burn the total volume of blood for aerobic meta O2.