Digestion 14.1-14.6

Which structure is not part of the GI tract?

• Stomach

• Jejunum

• Liver

• Esophagus

Answer explanation

The liver is not part of the gastrointestinal (GI) tract. The GI tract includes structures like the stomach, jejunum, and esophagus, which are involved in digestion and food passage.

Which accessory organ releases digestive enzymes into the small intestine?

• Salivary glands

• Liver

• Pancreas

• Gallbladder

Answer explanation

The pancreas is the accessory organ that releases digestive enzymes into the small intestine, aiding in the digestion of carbohydrates, proteins, and fats. The salivary glands, liver, and gallbladder have different functions.

Which term describes the release of enzymes, acid, and mucus into the GI tract?

• Digestion

• Secretion

• Absorption

• Motility

Answer explanation

The term 'Secretion' refers to the release of enzymes, acid, and mucus into the GI tract, which aids in digestion. This process is essential for breaking down food and facilitating absorption.

Peristalsis refers to:

• Mixing movements

• Rhythmic waves that push food forward

• Storage of food

• Enzyme secretion

Answer explanation

Peristalsis is a series of rhythmic muscle contractions that move food through the digestive tract, effectively pushing it forward. This distinguishes it from mixing movements, storage, or enzyme secretion.

Segmentation differs from peristalsis because segmentation:

• Moves food in one direction

• Mixes contents back and forth

• Happens only in the stomach

• Requires gravity

Answer explanation

Segmentation is a process that mixes food contents back and forth in the intestines, enhancing digestion and absorption. In contrast, peristalsis moves food in one direction through the digestive tract.

Which GI layer performs peristalsis and segmentation?

• Serosa

• Submucosa

• Muscularis

• Mucosa

Answer explanation

The muscularis layer of the gastrointestinal tract is responsible for peristalsis and segmentation, which are essential for moving and mixing food through the digestive system.

How many permanent teeth do adults typically have?

• 20

• 24

• 28

• 32

Answer explanation

Adults typically have 32 permanent teeth, which include incisors, canines, premolars, and molars. This number can vary if teeth are removed or not fully developed, but 32 is the standard count.

Which tooth type is specialized for cutting?

• Molars

• Premolars

• Canines

• Incisors

Answer explanation

Incisors are specialized for cutting due to their sharp, thin edges. They are located at the front of the mouth and are designed to bite into food, making them ideal for this function compared to molars, premolars, and canines.

Which part of saliva begins carbohydrate digestion?

• Pepsin

• Bile

• Salivary amylase

• Gastrin

Answer explanation

Salivary amylase is the enzyme in saliva that initiates carbohydrate digestion by breaking down starches into simpler sugars. Pepsin and gastrin are involved in protein digestion, while bile aids in fat digestion.

Saliva helps protect teeth because it contains:

• Pepsinogen

• Bicarbonate

• Bile salts

• Hydrochloric acid

Answer explanation

Bicarbonate in saliva helps neutralize acids in the mouth, protecting teeth from decay. Pepsinogen, bile salts, and hydrochloric acid are not components of saliva that contribute to dental protection.