If a blood clot forms, it can stop the blood flow. This can cause a heart attack or stroke. A heart attack occurs when the blood flow to a part of the heart is blocked by a blood clot. If this clot cuts off the blood flow completely, the part of the heart muscle supplied by that artery begins to die.
Digestion works by moving food through the GI tract. Digestion begins in the mouth with chewing and ends in the small intestine. As food passes through the GI tract, it mixes with digestive juices, causing large molecules of food to break down into smaller molecules.
Chemical digestion begins in the stomach, a large, hollow, pouchlike muscular organ. While food is still in the mouth, the stomach begins its production of gastric juice, which contains hydrochloric acid and pepsin, an enzyme that digests protein. Gastric juice is the material that breaks down the food.