Chapter 14 Test Review: Digestive System

1. Chapter 14 Test Review: Digestive System

2. Describe the following structures, and tell about their functions: mouth, lips/ labia, cheeks, and vestibule. • Oral cavity- mucous lined cavity • Lips (labia)- protects and controls the anterior opening • Cheeks- makes up the lateral walls of the mouth • Hard palate- anterior (front side) of the roof of the mouth • Soft palate- posterior (back side) of the roof of the mouth • Uvula- a finger like projection off the soft palate (hangs down at the back of the mouth) • Vestibule- the space between the lips/cheeks and the teeth • Oral cavity proper- the area contained within the teeth

3. What is the tongue? What holds it in place? • Tongue- makes up the floor of the mouth with bony extensions (hyoid and styloid bone) • Frenulum- a fold of mucous membrane that secures the tongue to the floor of the mouth

4. List and describe the layers of the esophageal wall. • Mucosa- inner most layer that lines the cavity of the organs; makeup- surface epithelium + connective • Tissue (lamina properia) + smooth muscle • Sub mucosa- just beneath the mucosa soft connective tissue; makeup of blood vessels and nerve endings • Muscularis externa- muscle layer (smooth); makeup- circular (inner) and longitudinal (outer) layers • Serosa- outermost layer; single layer with fluid producing cells = visceral peritoneum; VP is continuous with the parietal peritoneum that lines the abdominal cavity • Messentary- membranous extensions that connect the peritoneums

5. List and describe the regions of the stomach. • Made up of 4 regions • Cardiac region- surrounded by the cardioesophageal sphincter (where the food enters from the esophagus) • Fundus- the expanded portion of the stomach; lateral to the cardiac region • body- midportion • pylorus- the terminal end and continuous with the small intestines through the pyloric sphincter or valve

6. What are the valves entering and leaving the stomach? • cardioesophageal sphincter (where the food enters from the esophagus) • the terminal end and continuous with the small intestines through the pyloric sphincter or valve

7. What are the 2 major types of digestion? Where do they start? • food breakdown- both mechanical and chemical • Mechanical starts in the mouth by the process of mastication (chewing) • Chemical also starts in the mouth by the saliva (enzyme amylase) that breaks down starches; most chemical breakdown occurs in the stomach and small intestines

8. What is chyme? • chemical breakdown- carried out by the gastric glands through the gastric pits secrete gastric juices into the stomach; • chief cells- produces protein digestive enzymes • parietal cells- produces the corrosive hydrochloric acid • mucous neck cells- produces an alkaline mucous to line the stomach in order to protect it from the hydrochloric acid and gastric juices • Chyme- is a mixture of these enzymes and the food that enters into the stomach

9. List and describe the sections of the small intestines. Which one is the longest? • 3 subdivisions • duodenum- curves around the head of the pancreas; about 10 inches in length • jejunum- extends from the duodenum to the ileum; about 8 foot in length • ileum- the terminal end, connected to the large intestines at the iliocecal valve; about 6 foot in length • pyloric valve- regulates the amount of food going into the small intestines • enzymes help to complete the chemical breakdown of food in the small intestines;

10. What is bile? Where does it enter? Through what? • The liver produces bile for digestive purposes and the hepatic duct carries it to the duodenum • the liver also helps to emulsify (physical breakdown) fats • The gallbladder stores bile through the cystic duct when no digestion is occurring • during digestion, the gall bladder spurts out bile into the duodenum

11. What is appendicitis? What section does it occur? • Appendix • Accumulation of lymphatic tissue that sometimes becomes inflamed (appendicitis) • Hangs from the cecum • Cecum – saclike first part of the large intestine

12. List and describe the 2 anal sphincters. • rectum- in pelvis, holds the waste before elimination • anal canal- ends at the anus with the sphincter muscle

13. What is the largest gland in the body? • the liver is the largest gland in the body; it is located under the diaphram (on the right side of the body) • it almost completely covers the stomach • the liver has 4 lobes suspended from the diaphram and the abdominal wall by the falciform ligament

14. What accessory organ produces enzymes that neutralize chyme? • The pancreas produces an Alkaline fluid introduced with enzymes neutralizes acidic chyme

15. What are deciduous teeth? How many are there? At what age are they completed • 2 sets of teeth (completed by age of 21) • deciduous teeth- baby teeth or also called milk teeth (20 teeth are fully formed by age two) • permanent teeth- also includes wisdom teeth (32 teeth including the 4 wisdom teeth)

16. List and describe the different types of teeth. • Incisors • Canines • Premolars • Molars

17. Describe the structure of a tooth. • Crown – exposed part • Outer enamel • Dentin • Pulp cavity • Neck • Region in contact with the gum • Connects crown to root

18. Describe the structure of a tooth. • Root • Periodontal membrane attached to the bone • Root canal carrying blood vessels and nerves

19. What is charge of breaking down fat? • The liver produces bile for digestive purposes and the hepatic duct carries it to the duodenum • the bile helps to emulsify (physical breakdown) fats

20. Be able to locate all the parts of the alimentary canal (fig 14.1) on worksheet 218 • Mouth • Pharynx • Esophagus • Stomach • Small intestine • Large intestine • Anus

21. The End • Good Luck on your Test