Transcript document
Chapter 8 Digestive System Objectives Identify the organs of the digestive system Determine root words, prefixes and suffixes appropriate to this system Identify portions of the tooth Identify and define some common disorders Identify and explain medical treatments and procedures pertaining to the digestive system Gastroenterology Branch of medicine specializing in the diagnosis and treatment of diseases, conditions, affecting the lower gastrointestinal tract. (GI tract) Gastroenterologist is the physician who treats abnormal conditions of the GI tract Digestive system Also called the gastrointestinal system or Alimentary system (Latin alimentum) means nourishment Provides a tube like passage through a maze of organs and body cavities Begins at the mouth Ends at the anus The three main functions: Digestion Absorption Elimination Digestion Complex food material is taken in through the mouth and is digested (broken down) Digestive enzymes speed up chemical reactions and aid in the break down of complex nutrients Complex proteins are digested to amino acids Digestion contd: Complicated sugars are reduced to simple sugars such as glucose Large fat molecules are broken down into fatty acids and triglycerides Absorption: Takes place when the digested food is absorbed into the blood stream It is absorbed by going through the walls of the small intestine Fatty acids and glycerol enter the lymphatic vessels mostly Absorption contd: By this method valuable nutrients such as sugar, fatty acids and amino acids, travel to all cells of the body Cells then catabolize (burn) nutrients in the presence of oxygen to release energy stored within the food Cells also use amino acid nutrients to anabolize (build) large protein molecules needed for growth and development Elimination: Third function is the elimination of solid waste material that cannot be absorbed into the blood stream. The large intestine concentrates these solid wastes and pass it out of the body through the anus The waste is commonly known as ‘feces’ Organs of the Digestive system Mouth = or/o pertaining to the oral cavity Also known as the buccal cavity Includes the lips surround the opening to the cavity Cheeks: form the walls of the oval shaped cavity Hard palate: forms the anterior portion of the roof of the mouth Soft palate: muscular portion behind the hard palate. Made up of skeletal muscle and connective tissue Mouth contd: Rugae: Are irregular ridges in the mucous membrane covering the anterior portion of the hard palate Uvula: small soft tissue projection , hangs from the soft palate. Aids in sound and speech Tonsils: masses of lymphatic tissue located in depressions of the mucous membranes. They act as filters to protect the body from the invasion of microorganism Mouth contd: Tongue: solid, strong, flexible structure covered with mucous membranes. It extends across the floor of the oral cavity, and muscles attach it to the lower jaw bone (mandible) It moves food around during chewing (mastication) and swallowing (deglutition) Principle organ for taste Mouth contd: Papillae: small raised areas on the tongue Contain taste buds Gums: Fleshy tissue that surround the sockets of the teeth Teeth: Every individual has two sets of teeth in their lifetime. The shape of the tooth determines its name First set is ‘baby teeth’ (usually beginning to appear around age 6 months) are the primary teeth or deciduous teeth) and usually consist of 20 teeth. Second set ‘permanent teeth’ (usually starting at age 6 years) consist of 32 teeth Molar usually appear at age 17 years Pharynx: Also known as the throat A muscular tube lined with mucous membranes Food passes from the mouth to the pharynx to the esophagus Passageway for air traveling from the nose to the windpipe Esophagus: 9 to 10 inch muscular tube from pharynx to stomach Transports the food by means of peristalsis (involuntary process of wave like contractions) Esophagus the tube that connects your mouth and your stomach Stomach: Food passes from esophagus to stomach Made up of the Fundus – upper potion, bodymiddle portion, and antrum- lower portion Stomach contd: Lining consists of folds called Rugae This allows the stomach to stretch when food enters Sphincters are rings of muscle that control the openings into and from the stomach The cardiac sphincter relaxes and contracts moving food from the esophagus into the stomach Stomach contd: Pyloric sphincter allows food to leave the stomach when it has been broken down Food is churned and mixed with gastric juices to make semi liquid called chyme The stomach controls passage of food into the first part of the small intestine (duodenum) Food leaves the stomach in 1 to 4 hours or more Small intestine: Also known as small bowel Extends from the pyloric sphincter to the first part of the large intestine It is about 21 feet long Three parts; duodenum, jejunum, ileum. Completes digestion by way of intestinal enzymes, pancreatic enzymes and bile from the liver Large Intestine: Extends from the end of the ileum to the anus Four parts: cecum, colon, sigmoid colon, and rectum About five feet long Absorbs about 80% to 90% of fluids and electrolytes Excretes waste and feces Accessory Organs: Salivary glands Liver Gallbladder Pancreas Salivary Glands: Around the oral cavity there are three pairs of salivary glands. Parotid gland, Submandibular gland, Sublingual gland These glands produce saliva, which contain digestive enzymes Narrow salivary ducts carry the saliva into the oral cavity Liver: Produces a thick greenish fluid called bile Bile contains cholesterol, bile acids, and several bile pigments Bile is continuously released from the liver It then travels down the hepatic duct to the cystic duct which leads to the gallbladder which stores the bile Liver contd: Bile acts as an emulsifying agent on large fat globules Without bile most of the fat in the body remains undigested The liver also maintains normal blood glucose Manufactures blood protein particularly the ones used for blood clotting Remove poisons from the blood Gall bladder: Stores bile from the liver until needed in the duodenum to aid in digestion We can do without our gallbladder If removed bile will find another home in the biliary ducts to continue its process Pancreas: Both an exocrine and endocrine organ As an exocrine gland it produces enzymes to digest starch, fat, and proteins As an endocrine gland it secretes insulin, which is used as a carrier to bring glucose into cells of the body for energy Root words: An/o Appendic/o Bil/I Bucc/o Cec/o Cheio/o Chol/e Anus Appendix Gall, bile Cheek (Facial) Belly Saliva Gall, bile Root Words contd: Cholecyst/o Col/o Colon/o Dent/o Duoden/o Enter/o Esophag/o Gall bladder Colon Teeth Duodenum Small intestine Esophagus Root words contd: Gastr/o Gingiv/o Gluc/o Glyc/o Hepat/o Ile/o Jejun/o Stomach Gums Sugar Sugar Liver Ileum Jejunum Root words contd: Labi/o Lingu/o Gloss/o Lip/o Or/o Pancreat/o Peritone/o Lips Tongue Tongue Fat, lipids Mouth, oral Pancreas Peritoneum Root words contd: Pharyng/o Proct/o Rect/o Sigmoid/o Splen/o Pharynx Anus, rectum Rectum Sigmoid colon Spleen Prefix: ReRetro- Back Backward, back Suffix: -ase -flux -iasis -lithiasis -lytic -pepsia -prandial Enzyme Flow Abnormal condition stone destruction, breakdown digestion meal Suffix contd: -orrhaphy -ostomy -tresia -tripsy suturing artificial opening opening crushing