Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Drawing of the layers of the small intestine showing the complex ENS network, differentiated cells, and neurotransmitters. iPAN: intrinsic primary afferent neuron; EEC: enteroendocrine cell; Ach: acetylcholine; CGRP: calcitonin gene-related peptide; VIP: vasoactive intestinal peptide; ATP: adenosine triphosphate; NO: nitric oxide; CO: carbon monoxide; 5-HT: serotonin.
