Match each GI wall structure with its location or defining feature.

Each pairing identifies a defining location from the lecture. The **serosa** covers the outer surface of most of the tract; the **myenteric plexus** is between the muscle coats; the **submucosal plexus** lies in connective tissue of the submucosa; and the **mucosa** faces and communicates with the lumen. These distinctions prevent common errors, especially confusing the two plexuses or reversing the inner and outer surfaces. **Key takeaway:** Use each structure’s position in the wall to distinguish it from neighboring layers.\n\n**Glossary:**\n- **Serosa**: External covering of most of the GI tract.\n- **Submucosa**: Connective tissue layer containing the submucosal plexus.\n- **Lumen**: The channel through which GI contents move.