Chapter 8 Digestive System Learning Outcomes 1 Describe

Chapter 8 Digestive System

Learning Outcomes 1. Describe the digestive system. 2. Explain the primary functions of the organs of the digestive system. 3. Describe the two sets of teeth found in humans. 4. Identify the three main portions of a tooth.

Learning Outcomes 5. Discuss the accessory organs of the digestive system and state their functions. 6. Analyze, build, spell, and pronounce medical words. 7. Describe diagnostic and laboratory tests related to the digestive system.

Key words/Combo Forms ¡Difference b/w exocrine and endocrine ¡Know the combining forms on page 219 ¡ Prand/i = meal ¡ Proct/o = anus and rectum ¡ Hepat/o = liver ¡ Ondot/o = tooth ¡Knowing these will help you break down medical words listed in 219 -236

Bolus Journey Path ¡Mouth/Teeth/ ¡Liver ¡Salivary Glands ¡Gallbladder ¡Pharynx/Esophagus ¡Pancreas ¡Stomach ¡Small Intestine ¡Large Intestine ¡Highlight procedures and drugs

Group Work/Individual Work ¡Visuals/Overviews for parts of the digestive system ¡List functions according to selected region or area ¡List key combining forms for specific area (e. g. , liver is hepat/o, or labi/o is lip) ¡Create One Multiple Choice Question

Figure 8. 1 Digestive system.

TABLE 8. 1 Digestive System at-a-Glance

You. Tube- An Overview ¡http: //www. dnatube. com/video/8362/Animatio n-of-the-digestive-system

Resources ¡https: //www. nlm. nih. gov/medlineplus/digestivesystem. html

Anatomy and Physiology Overview ¡General description of the digestive or gastrointestinal system: a continuous tube beginning with the mouth and ending at the anus. ¡This tube is known as the alimentary canal and/or gastrointestinal tract and is about 30 feet long in adults.

Anatomy and Physiology Overview ¡Digestive system contains both primary and accessory organs for the conversion of food and fluids into a semiliquid that can be absorbed for the body to use. ¡Three main functions: ¡ Digestion ¡ Absorption ¡ Elimination https: //youtu. be/5_Bi. Pd. WRVCw

TABLE 8. 2 Components of Chemical Digestion

Mouth ¡Tongue = Lingu/o: ¡ Made of skeletal muscle and covered with mucous membrane ¡ Can be divided into: ¡ Root ¡ Pointed tip ¡ Central body ¡Papilla(e) (elevations) and taste buds (sweet, salt, sour, and bitter) are located on the tongue's surface.

Figure 8. 2 (continued) Oral cavity: (B) anterior view as seen through the open mouth.

Teeth ¡Two Sets ¡ 20 deciduous teeth, also referred to as milk teeth or baby teeth ¡ 32 permanent teeth ¡ 8 incisors ¡ 4 canines ¡ 8 premolars ¡ 12 molars

Teeth ¡Each tooth consists of three main portions: ¡ Crown ¡ Neck ¡ Root

Figure 8. 4 Teeth. (A) Diagrammatic section through a typical adult tooth.

Figure 8. 4 (continued) Teeth. (B) The adult teeth.

Epiglottis – break it down

Figure 8. 3 Movement of a bolus of food from the mouth to the esophagus. The bolus then travels to the stomach.

Pharynx ¡ A chamber that extends between the internal nares and the entrance to the larynx and esophagus

Pharynx (Pharynge/o) ¡The pharynx is a common passageway for both respiration and digestion. ¡Both the larynx, or voice box, and the esophagus begin in the pharynx. ¡The epiglottis (a flap of tissue) blocks the opening of the larynx, preventing food from entering the airway leading to the trachea (windpipe).

Esophagus ¡A muscular tube about 10 inches long that leads from the pharynx to the stomach. ¡The lower esophageal or cardiac sphincter is at the junction with the stomach. ¡This esophageal sphincter: ¡ relaxes to permit passage of food. ¡contracts to prevent the backup of stomach contents.

Esophagus = Esophag/o ¡Food is carried along the esophagus by a series of wavelike muscular contractions called peristalsis. ¡https: //youtu. be/KJa. M 34 vm. Mhs

Stomach = Gastr/o ¡A muscular, distensible saclike portion of the alimentary canal between the esophagus and duodenum. ¡Fundus: upper region of the stomach. ¡Body: the main portion. ¡Antrum: the lower region. ¡Rugae: folds in the mucous membrane lining the stomach ¡https: //youtu. be/Yoo 91 B 3 a. Vbw

Figure 8. 5 Stomach = Gastr/o

Small Intestine ¡About 21 feet long and 1 inch in diameter. ¡Extends from pyloric sphincter at base of stomach to entrance of large intestine. ¡Divided into three parts: ¡ Duodenum (doo″o-de´num) ¡ Jejunum (jĕ-jū'nŭm) ¡ Ileum (il'ē-ŭm) Do not confuse this word with ilium.

Figure 8. 6 Small intestine.

Small Intestine ¡Chyme is mixed with bile and pancreatic juice. ¡Digestion and absorption take place chiefly in the small intestine. ¡Tiny capillaries and lymph vessels absorb nutrients, which are transferred to body cells by the circulatory system. ¡https: //youtu. be/VSATCz. Xq. Lr 0

Large Intestine ¡About 5 feet long and 2. 5 inches in diameter. ¡Divided into: ¡ Cecum ¡ Colon (colon/o) ¡ Rectum (rect/o) ¡ Anal canal (proct/o = anus and rectum) https: //youtu. be/o. Zgx_52 v. VTU

Figure 8. 7 Large intestine.

Accessory Organs ¡These organs are not actually part of the digestive tube but are closely related to the digestive process: ¡ Salivary glands ¡ Liver ¡ Gallbladder ¡ Pancreas ¡ https: //youtu. be/0 n 6 MJqm. KFz. Y

Accessory Organs ¡Salivary Glands (Sial/o = saliva, salivary) ¡ Located in or near the mouth. ¡ Secrete saliva in response to sight, smell, taste, or mental image of food. ¡Salivary Glands ¡ Parotid ¡ Submandibular ¡ Sublingual

Figure 8. 8 Salivary glands, salivary ducts and the tongue.

Accessory Organs ¡Liver = Hepat/o ¡ The largest glandular organ in the body. ¡ Weighs about 3 ½ lbs. ¡ Located in the upper right part of the abdomen. ¡ Plays an essential role in the normal metabolism of carbohydrates, fats, and proteins.

Figure 8. 9 Liver.

Accessory Organs ¡Carbohydrate Metabolism ¡ Changes glucose to glycogen and stores it until needed by body cells. ¡ When required, glycogen is converted back to glucose. ¡Fat Metabolism ¡ The liver serves as a storage place and acts to desaturate fats before releasing them into the bloodstream. ¡Protein Metabolism ¡ The liver acts as a storage place and assists in both protein anabolism and catabolism.

Accessory Organs ¡The liver manufactures the following important substances: ¡ Bile ¡ Fibrinogen and prothrombin ¡ Heparin ¡ Blood proteins ¡The liver stores iron and vitamins B 12, A, D, E, and K. ¡Detoxifies many harmful substances (toxins), such as drugs and alcohol.

Figure 8. 15 The liver in this photograph was from a deceased patient with an advanced state of cirrhosis.

Accessory Organs ¡Gallbladder (Chol/e = gall, bile) ¡ A small, pear-shaped sac attached to the liver in which excess bile is stored and concentrated. ¡ Concentration is accomplished by reabsorption of water. ¡ What causes gallbladder stones?

Figure 8. 14 Gallbladder with gallstones. Note the stones in the hepatic duct, gallbladder, and common bile duct. http: //www. niddk. nih. gov/health-information/healthtopics/digestive-diseases/gallstones/Pages/facts. aspx

Accessory Organs ¡Pancreas = Pancreat/o ¡ A large, elongated gland situated behind the stomach and secreting pancreatic juice into the small intestine. ¡ Contains cells that produce digestive enzymes. ¡ Other specialized cells secrete the hormones insulin and glucagon directly into the bloodstream. ¡ Check out here for an explanation of the endocrine and exocrine functions

Figure 8. 10 Pancreas.

Group Work/Individual Work ¡Visuals/Overviews for parts of the digestive system ¡List functions according to selected region or area ¡List key combining forms for specific area (e. g. , liver is hepat/o, or labi/o is lip) ¡Create One Multiple Choice Question