Which layer houses Meissner's plexus and what is its primary function?

• A. Submucosa; regulates secretion and local blood flow
• B. Muscularis externa; regulates GI motility
• C. Serosa; protects
• D. Mucosa; absorption

Answer: (A)

Meissner's plexus is the submucosal nervous plexus, located in the submucosa. Its role is to regulate local secretions and blood flow to the mucosa, helping coordinate glandular activity and the mucosal environment in response to luminal contents. This supports digestion by adjusting mucus secretion and the blood supply where absorption and protection occur. The other layers have different primary roles: the muscularis externa houses the myenteric (Auerbach) plexus and mainly controls GI motility; the serosa provides outer protection; and the mucosa handles absorption and secretion, but the neural control for local secretion and vascular regulation is specifically in the submucosa through Meissner's plexus.