Electrolyte transport across the bird coprodeum: role in osmoregulation

摘要

Birds are, in general, not exposed to an ' unbalanced' external environment. But the lower end of their gut certainly encounters an extremely ' unbalanced' internal environment. The reason for this is the mixing of ureteral urine and faeces (Fig. 1) which takes place in the coprodeum and large intestine (Skadhauge, 1968). The coprodeum is the stage for final salt and water conservation both from renal and intestinal sources. The variable composition of the contents of the coprodeum and large intestine, largely influenced by the variable rate of urine flow and composition of ureteral urine, heavily influences the transmural transport rates in these organs.