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.
The first stage of digestion takes place in the mouth. Salivary glands located under the tongue, and in the back of the mouth, produce saliva in the mouth. Enzymes in the saliva start the chemical digestion of food. Amylase starts the breakdown of carbohydrates, while salivary lipase begins the breakdown of fats. Once the food arrives at the stomach, gastric glands secrete pepsinogen and hydrochloric acid.