Subtraction is the inverse of addition. 2. Either of two numbers or quantities that cancel each other out under a given mathematical operation. For example, the inverse of 5 under multiplication is 1 / 5, since 5 Ã 1 / 5 = 1.
Peptic ulcer disease refers to painful sores or ulcers in the lining of the stomach or first part of the small intestine, called the duodenum. No single cause has been found for ulcers. However, it is now clear that an ulcer is the end result of an imbalance between digestive fluids in the stomach and duodenum. Most ulcers are caused by an infection with a type of bacteria called Helicobacter pylori (H. pylori).
The types of peptic ulcers are gastric and duodenal, both of which are chronic diseases. The ulcer represents the development of a circumscribed defect in the gastric or duodenal mucosa that is exposed to acid and pepsin secretion. The ulcer may extend through the tissue layers of the muscle and serosa into the abdominal cavity.