Chapter Objectives

2. Describe the production, storage and purpose of bile.

Bile is produced in the liver. Bile is concentrated within the gallbladder as a result of hydrolysis. In an abnormal situation, when too much water is absorbed, or the cholesterol becomes too concentrated, gallstones may form in the gallbladder. The gallbladder normally contracts when foods such as fts are in the duodenum. These foods stimulate the duodenal mucosa to secrete the hormone CCK. Increased levels of CCK in the blood cause the gallbladder to contract and the terminal opening of the common bile duct to relax. When bile is not needed for digestive purposes, it is stored for future use in the gallbladder.

4. Describe the effect of body habitus on the location of the gallbladder.

It has a major impact on the location of the GI organs within the abdominal cavity. To position for gastrointestinal procedures accurately and consistently, one must know and understand the characteristics of each of these classes of body habitus.

Hypersthenie- stomach is high and transverse at the level of T9 to T12 and is placed to the right of the midline.

Sthenic- stomach is at the level of T10-L2. Duodenal bulb is closer to the midline.

Hyposthenic- Low and vertical stomach at the level of T11. The duodenal bulb is located at level L3 at the midline.

8. List the major organs of the upper gastrointestinal system and specific accessory organs.

Oral cavity, pharynx, esophagus, stomach, duodenum ad the small intestine are all organs of the upper GI system. The specific accessory organs include the salivary glands, pancreas, liver, and gallbladder.

9. List the three primary functions of the digestive system.

The first primary funcion is the intake or digestion of food, water vitamins and minerals. It must be broken down so that absorption can occur.

The second function of the digestive system is to absorb digested food particles, along with water, vitamins and essential elements from the alimentary canal into the blood or lymphatic capillaries.

The third function is to eliminate any unused material in the form of semisoilid waste products.

10. List three divisions of the pharynx.

Nasopharynx- posterior to the bony nasal septum, nasal cavities and soft palate.

Oropharynx- directly posterior to the oral cavity proper.

Laryngopharynx- extends from the levelof the epiglottis to the level of the lower border of the larynx.

15. Identify differences between mechanical digestion and chemical digestion.

Mechanical digestion includes all movements of the gastrointestinal tract, beginning in the oral cavity with chewing and continuing in the pharynx and esophagus with swallowing.

Chemical digestion includes all the chemical changes that food undergoes as it travels through the alimentary canal.