BIOC34H3 Lecture Notes - Lecture 24: Enteric Nervous System, Enterochromaffin-Like Cell, Prevertebral Ganglia
Document Summary
Lecture 24: nervous and hormonal regulation of digestion: gi tract nerve plexes, gut motility and secretion of substances are controlled by two nerve plexes. Innervating the sub-mucosa layer is the submucosal nerve plexis, and innervating the smooth muscle is the myenteric nerve plexis. Submucosal plexis influences secretory activity and is closer to intestinal lumen. Smooth muscle can contract and relax without nervous or hormonal regulation: sensory pathways and receptors, there are a host of different receptor types in the gut that can sense chemical stimuli coming from breakdown of food. Chemoreceptors sense changes in ph, sugars, amino acids, and fatty acids. Again, there are three major components to it. Gastric phase: effects of protein digestion products: g cells detect protein digestion products (amino acids and peptides) causing the release of gastrin. Gastrin circulates in the blood and stimulates the parietal cells to release hcl.
