The anus the anal canal and squamous cell carcinomas

The anus, the anal canal and squamous cell carcinomas
The anus is right at the end of the gastrointestinal tract - the area right at the end. While the anal canal is the tube that connects the rectum to the outside of the body. The anal canal is surrounded by the sphincter - a muscle. The sphincter controls bowel movements by contracting and relaxing. In short, the anus is the outside area while the anal canal is the tube.
The point at which the anal canal meets the rectum is called the transitional zone. The transitional zone has squamous cells and glandular cells - these produce mucus which helps the stool (feces) pass through the anus smoothly. Adenocarcinoma (type of cancer) of the anus can develop from these glandular cells. However, squamous cell carcinomas make up the vast majority of anal cancers.