QUIZ 3: DIGESTIVE SYSTEM

Which of these glands does not secrete saliva into the oral cavity? a. submandibular gland b. pancreas c. sublingual gland d. parotid gland

b. pancreas

during swallowing, a. the movement of food results primarily from gravity. b. the swallowing center in the medulla oblongata is activated. c. food is pushed into the oropharynx during the pharyngeal phase. d. the soft palate closes off the opening into the larynx

b. the swallowing center in the medulla oblongata is activated

Which of these stomach cell types is not correctly matched with its function? a. surface mucous cells—produce mucus b. parietal cells—produce hydrochloric acid c. chief cells—produce intrinsic factor d. endocrine cells—produce regulatory hormones

c. chief cells - produce intrinsic factor

-- digestion, which is accomplished by digestive enzymes secreted along the digestive tract.

chemical

. the breakdown of large organic molecules into their component parts: carbohydrates into monosaccharides, proteins into amino acids, and triglycerides into fatty acids and glycerol.

digestion

Which of these hormones stimulates stomach secretions?

gastrin

the intake of solid or liquid food into the stomach. The normal route of ingestion is through the oral cavity.

ingestion

-- digestion, which involves the mastication and mixing of food

mechanical

The number of premolar deciduous teeth is

0

the stomach a. has large folds in the submucosa and mucosa called rugae. b. has two layers of smooth muscle in the muscularis tunic. c. opening from the esophagus is the pyloric opening. d. has an area closest to the duodenum called the fundus. e. All of these are correct.

a. has large folds in the submucosa and mucosa called rugae.

The portion of the digestive tract in which digestion begins is the a. oral cavity. b. esophagus. c. stomach. d. duodenum. e. jejunum.

a. oral cavity

the movement of molecules out of the digestive tract and into the blood or into the lymphatic system. The mechanism by which absorption occurs depends on the type of molecule involved. Molecules pass out of the digestive tract by diffusion, facilitated diffusion, active transport, symport, or endocytosis

absorption

Why doesn't the stomach digest itself? a. The stomach wall is not composed of protein, so it is not affected by proteolytic enzymes. b. The digestive enzymes of the stomach are not strong enough to digest the stomach wall. c. The lining of the stomach wall has a protective layer of epithelial cells. d. The stomach wall is protected by large amounts of mucus.

d. The stomach wall is protected by large amounts of mucus

dentin a. forms the surface of the crown of the teeth. b. holds the teeth to the periodontal ligaments. c. is found in the pulp cavity. d. makes up most of the structure of the teeth.

d. makes up most of the structure of the teeth

the process by which the waste products of digestion are removed from the body. During this process, which occurs primarily in the large intestine, water and salts are absorbed, changing the material in the digestive tract from liquefied to semisolid. These semisolid waste products, called feces, are then eliminated from the digestive tract by the process of defecation

elimination

contractions that move material in the distal parts of the large intestine to the anus.

mass movements

the process by which the teeth chew food in the mouth.

mastication

Some contractions do not propel food from one end of the digestive tract to the other but, rather, move it back and forth within the digestive tract to mix it with digestive secretions and help break it into smaller pieces.

mixing

Which layer of the digestive tract is in direct contact with the food that is consumed?

mucosa

propels material through most of the digestive tract. Peristaltic waves are muscular contractions consisting of a wave of relaxation of the circular muscles in front of the bolus, followed by a wave of strong contraction of the circular muscles behind the bolus, which force the bolus along the digestive tube.

peristalsis

the movement of food from one end of the digestive tract to the other. The total time it takes food to travel the length of the digestive tract is usually about 24-36 hours

propulsion

As food moves through the digestive tract, secretions are added to lubricate, liquefy, buffer, and digest the food. Mucus, secreted along the entire digestive tract, lubricates the food and the lining of the tract. The mucus coats and protects the epithelial cells of the digestive tract from mechanical abrasion, stomach acid, and digestive enzymes.

secretion

are mixing contractions that occur in the small intestine.

segmental contraction

The ENS is found in

submucosa and muscularis layer

moves liquids or a soft mass of food and liquid, called a bolus, from the oral cavity into the esophagus.

swallowing