A blood alcohol concentration (BAC) or blood alcohol level (BAL) reflects the amount of alcohol in the body. Food, type and quantity of beverage, weight, sex, and rate of elimination determine the BAC after the consumption of alcohol.
The process of oxygen transfer in the gills of a fish is a good example of the benefits of countercurrent exchange. As oxygen poor blood meets an opposed flow of oxygen rich water, the oxygen begins to diffuse out of the water and into the blood stream.
Gas exchange in bony fish: water is drawn into the mouth and passed over the gills. Counter-current flow mechanism: in the gills, the flow of blood is in the opposite direction to the flow of water across the gills. This means that blood is continually meeting fresh water with a higher percentage saturation of oxygen.as exchange in bony fish: water is drawn into the mouth and passed over the gills. Counter-current flow mechanism: in the gills, the flow of blood is in the opposite direction to the flow of water across the gills. This means that blood is continually meeting fresh water with a higher percentage saturation of oxygen.