What layer of the alimentary canal tissue is capable of helping to protect th

What layer of the alimentary canal tissue is capable of helping to protect the body against disease, and through what mechanism?
Describe the three regions of the pharynx and their functions.
What is suggested by the presence of white blood cells found in the urine?
Why are females more likely to contract bladder infections than males?
Describe three of the differences between the walls of the large and small intestines.