PHYSIOL 201 Lecture Notes - Lecture 28: Serous Membrane, Enterochromaffin-Like Cell, Duodenum
Document Summary
The gi track has multiple organs associated with it. Have the track itself and then we also have the accessory organs. Associated with the external environment in the top and bottom. Unless we digest and absorb the material, it is not part of our body. So everything in the tract is part of the external environment. Not where the food is travelling through and being digested and absorbed. These secrete substances into the tract that are required for or helpful with to make the whole process more efficient. If it was, we would eat and then only substances that were required would be. The gi tract is set up to maximize digestion and absorption. If we eat it, the tract will absorb it do that. Gi tract does not play a major role in excretion of waste products absorbed and anything that isn"t will be excreted. There are other signals that help maintain calorie intake but the tract itself doesn"t.
