D I G E S T I V E<br />S Y S T E M<br />by<br />Beatriz <br />
The digestive system is also known as the<br />gastrointestinal (GI) system.<br />Main functions of the digestive system:<br />Digesting food<br />Absorbing nutrients<br />Eliminate waste<br />
FUNCTION<br /> The digestive system begins breaking down food through mechanical and chemical digestion. After being digested, nutrient molecules are absorb into the body and enter the blood stream. Any food not digested or absorbed is eliminated as solid waste.<br />
When does the digestion begins?<br />Digestion begins in the mouth. The saliva contains digestive enzymes to break down carbohydrates and slippery lubricants to make food easy to swallow.<br />
ORAL CAVITY<br />Taste buds is found on the surface of the tongue, can distinguish the bitter, sweet, sour, and salty flavors in our food.<br /> Hanging down from the posterior edge of the palate (roof of the mouth) is the uvula which provide the speech production and help to help to prevent food from entering the lungs.<br />
TEETH<br /> Teeth are an important part of the first stage of digestion. <br /> The teeth in front of the mouth helps to bite, tear, or cut food into small pieces.<br />INCISORS<br />CUSPIDS (CANINES)<br /> The remaining posterior teeth grind and crush food into even finer pieces.<br />BICUSPIDS (PREMOLAR)<br />MOLARS<br />
PHARYNX<br /> When food is swallowed, it enters the oropharynx and then the laryngopharynx.The epiglottis is a cartilaginous flap that folds down to cover the larynx and trachea, preventing food from entering the respiratory tract and instead continues into the esophagus.<br />
ESOPHAGUS<br />The esophagus is a muscular tube of about 10 inches long in adults.<br /> Food entering the esophagus is carried through the thoracic cavity and diaphragm and into de abdominal cavity where it enters the stomach.<br />
STOMACH<br /> It is a J-shaped muscular organ that acts as a bag or sac to collect and churn food with digestive juices, is composed of three parts<br />FUNDUS (upper region)<br />BODY (main portion)<br />ANTRUM (lower region)<br />
Rugae: Foldings in the lining of the stomach<br />When the stomach fills with food the rugae stretch out and disappear.<br />Hydrochloric acid is secreted by glands in the mucous membrane lining of the stomach.<br />Foods mixes with hydrochloric acid and other gastricjuices to form a liquid mixture called chyme. <br />Food is propelled along the esophagus by <br />wavelike muscular contractions called peristalsis.<br />
Small intestine<br />The small intestine, or small bowel, is the major site of digestion and absorption of nutrients from food. It is located between the pyloric sphincter and the colon. The sigmoid colon curves in an S-shape back to the midline of the body and ends at the rectum, where the feces are stored. It has three sections:<br />DUODENUM<br />JEJUNUM<br />ILEUM<br />
ACCESSORY ORGANS OF THE DIGESTIVE SYSTEM<br />SALIVARY GLANDSHelping in the oral cavity produce saliva, which allows food to be swallowed without chocking.<br />LIVERProcess the nutrients absorbed by the intestines, detoxifying harmful substances in the body and producing bile which is important for the digestion of fats and lipids.<br />GALLBLADDERA small organ located just under the liver. It functions to store the bile produced by the liver. <br />PANCREAS<br />Also an endocrine gland that produces the hormones insulin and glucagon, which play a role in regulating the level of glucose in the blood.<br />
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