Molecularly defined serotonin (enterochromaffin) cells of the gut lining were distinguished by single-cell expression analysis, in situ hybridization, and immunohistochemistry into 14 topographically ...

In comparisons, consider lifestyles and evolutionary history of animals. Pancreas marks duodenum. Jejunum, ileum: attaches to large intestine and colon at a T junction with caecum or appendix.