$$\text{Saliva Water Content} = \frac{99.5}{100} \times 100\%$$

$$\text{Enzyme Activity} \propto \text{Surface Area}$$

$$\text{Absorption}_{\text{stomach}} \ll \text{Absorption}_{\text{small intestine}}$$

Question 1

Which layer of the GI tract is primarily responsible for absorption and secretion, and what are its main components?

Accepted Answer

Mucosa; composed of epithelium, lamina propria, and muscularis mucosa

Question 2

During the act of swallowing (deglutition), which phase involves the epiglottis folding downward to prevent food from entering the airway?

Accepted Answer

Pharyngeal phase

Question 3

Which of the following best describes the function of the parietal peritoneum?

Accepted Answer

It adheres to the inner wall of the abdominal cavity

Question 4

A patient presents with difficulty in the chemical breakdown of food in the oral cavity. Which structure is most likely impaired?

Accepted Answer

Salivary glands

Question 5

Which region of the stomach is primarily responsible for mixing and holding food before absorption begins?

Accepted Answer

Antrum (pylorus)

Question 6

If a drug is absorbed directly from the stomach, which property does it most likely possess?

Accepted Answer

It is nonpolar and small

Question 7

Which of the following best explains why mastication increases the rate of enzyme activity in the oral cavity?

Accepted Answer

It increases the surface area of food particles

Question 8

Which equation best represents the percentage of water in saliva?

Accepted Answer

$$	ext{Saliva Water Content} = \frac{99.5}{100} 	imes 100\%$$

Question 9

Which cell type in the gastric glands is responsible for secreting hydrochloric acid ($$HCl) $$and intrinsic factor?

Accepted Answer

Parietal cells

Question 10

A patient with a deficiency in intrinsic factor would most likely develop which condition?

Accepted Answer

Pernicious anemia

Question 11

Which phase of digestion is initiated by sensory receptors in the head and stimulates gastric secretion and motility?

Accepted Answer

Cephalic phase

Question 12

Which of the following is NOT a function of the oral cavity?

Accepted Answer

Absorption of nutrients

Question 13

Which structure connects the oral cavity to the esophagus and is divided into three regions?

Accepted Answer

Pharynx

Question 14

Which equation best represents the relationship between enzyme activity and surface area during mastication?

Accepted Answer

$$	ext{Enzyme Activity} \propto 	ext{Surface Area}$$

Question 15

Which of the following best describes the mechanical digestion in the stomach?

Accepted Answer

Peristaltic muscle contractions mix food

Question 16

Which cell type in the gastric glands secretes pepsinogen?

Accepted Answer

Chief cells

Question 17

Which of the following is a correct sequence for the layers of the GI tract from innermost to outermost?

Accepted Answer

Mucosa, submucosa, muscularis, serosa/adventitia

Question 18

Which equation best represents the minimal absorption in the stomach for substances like alcohol and aspirin?

Accepted Answer

$$	ext{Absorption}_{	ext{stomach}} \ll 	ext{Absorption}_{	ext{small intestine}}$$

Question 19

Which of the following is true regarding the serosa layer of the GI tract?

Accepted Answer

It is also known as the adventitia when outside the peritoneal cavity

Question 20

Which phase of digestion is primarily under neural and hormonal control and occurs in the small intestine?

Accepted Answer

Intestinal phase

Digestive System: Structure and Function (Ch. 22 Anatomy & Physiology)

Study Guide - Practice Questions