The horse's digestive system is a long and complex system that ensures that a horse receives enough nutrients in different parts of its body. It is also a very delicate system due to its size and complex nature. With all of the different twists and turns involved in the digestive process, it is easy for this process to go wrong, which could cause the horse extreme discomfort or even death. The digestion process begins with the grass. . To survive, a horse needs grass, and to grow grass, it needs fertilization, which is provided by waste from the horse's digestive tract. It's a continuous cycle and if one didn't have the other to help it grow, it wouldn't thrive as well. So now the cycle begins with picking up the food. When a horse bends down to pick up a piece of food it wants to eat, it uses its teeth. Teeth are very important for a horse. A horse uses them to hold the food it eats and uses its molars to grind the food into many small pieces. Additionally, as the horse grinds the food, the tongue is used to hold the food in place so that it does not slide to the front of its mouth or change position when it does not want it to. Once the horse has thoroughly ground its food. he swallows it and sends it down his esophagus. The esophagus is one of the simplest parts of a horse's digestion. It is simply a passage between the mouth and the stomach made up of rings of muscles that contract and relax to bring food to the stomach. At the bottom of the esophagus is a muscle called the cardiac sphincter. This muscle holds food inside the horse's stomach, so if a horse were to suddenly stop eating and run away middle of paper......management, it expels the remains of undigested food so that more plants can grow. Then an animal eats that and the cycle starts again. We continually ensure that plants and animals all receive the right amount of nutrients to survive, so that many more generations can follow. Works Cited Oke, Stacey. 2010. The horse's digestive system: basic principles of the structure and function of the equine digestive tract. Accessed October 2, 2010 http://www.thehorse.com/pdf/factsheets/digestive-tract.pdf2008. Horse anatomy of the digestive system. Accessed October 2, 2010, http://www.understanding-horse-nutrition.com/horse-anatomy.html2005. Colic. Accessed October 2, 2010, http://www.ultimatehorsesite.com/info/colic.html2010. How the digestive system works. Accessed October 2, 2010, http://newrider/Library/Horse_Care/digestion.html