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.
Organs of the Gastrointestinal Tract. Oral cavity. This is your mouth, and while it's not technically an organ, it's important because digestion begins in your mouth when you bite and chew your food, thus mixing it with saliva. The saliva (or spit) moistens food so that it's easier to swallow. It also contains a little bit of salivary amylase, a digestive enzyme that breaks down carbohydrates.