Figure 1
From: The role of endoscopic ultrasound in the evaluation of rectal cancer
Correlation between the standard five EUS layers and histological layers of the normal intestinal wall. 1st = interface between fluid in the lumen and the superficial mucosa; 2nd = lamina propria and muscularis mucosa, or deep mucosa; 3rd = submucosa and interface between submucosa and muscularis propria; 4th = muscularis propria; circular (4a) and longitudinal (4c) are not usually seen as separate layers; 5th = interface between serosa and surrounding adventitial tissue.