Gill breathing
Under Kiemenatmung , meaning the exchange of gases oxygen and carbon dioxide of many water-living animals between the blood and the surrounding water, which in the gills is going on. Because of their delicacy and vulnerability, the gills are often covered by protective devices (shell, cloak cavity, gill cover ). This position requires active ventilation .
In gill breathing, principles of surface enlargement , compartmentalization and countercurrent (pigment system / blood and water flow in the opposite direction) are implemented for more efficient gas exchange in oxygen-poor water (generally to air). The blood flowing through the gills circulates in a "closed circulatory system".
When flowing into the gill, oxygen-rich water meets oxygen-poorer blood. This difference in partial pressure causes a diffusion of oxygen from the water into the blood. Due to the countercurrent, the blood leaving the gill has more oxygen than the water flowing away. The oxygen yield is additionally increased by very thin slits between the gill lamellae, since the diffusion path is so extremely short. The transport of oxygen in the organism is ensured by a pigment system and leads it to the cells; the carbon dioxide produced by biological oxidation is transported away accordingly.
literature
- Michael Leiner: The Physiology of Fish Breathing . Academic Publishing Company, Leipzig 1938, DNB 36115125X .