Nokea
Surface area of the stomach is increased by
- A. gastric pits.
- B. plicae circulares.
- C. villi.
- D. microvilli.
Correct Answer: A
Rationale: The correct answer is A: gastric pits. Gastric pits are invaginations in the stomach lining that contain specialized cells for secretion of gastric juices. These pits increase the surface area of the stomach by providing a larger area for nutrient absorption and digestion. Plicae circulares are folds in the small intestine, not the stomach. Villi and microvilli are found in the small intestine and further increase surface area for absorption, not in the stomach.
You may also like to solve these questions
Which statement accurately describes vitamin deficiencies?
- A. The two nutrients most often lacking in the diet of a vegan are vitamin B6 and folic acid.
- B. Vitamin imbalances occur frequently in the United States because of excessive fat intake.
- C. Surgery on the GI tract may contribute to vitamin deficiencies because of impaired absorption.
- D. Vitamin deficiencies in adults most commonly are clinically manifested by disorders of the skin.
Correct Answer: C
Rationale: The correct answer is C because surgery on the gastrointestinal (GI) tract can impair the absorption of essential vitamins leading to deficiencies. This is due to the fact that many vitamins are absorbed in the GI tract, and any alteration or removal of parts of the tract can hinder this process. For example, surgeries like gastric bypass can reduce the absorption of certain vitamins such as B12.
Choice A is incorrect because vegan diets can be deficient in various nutrients, not just vitamin B6 and folic acid.
Choice B is incorrect because vitamin imbalances are not solely due to excessive fat intake but can also be caused by various factors.
Choice D is incorrect because while skin disorders can be a symptom of vitamin deficiencies, they are not the most common clinical manifestation in adults.
The nurse explains that the older adult is prone to digestive disorders related to which age-related change?
- A. Decreased hydrochloric acid
- B. Increased enzyme levels
- C. Inadequate chewing
- D. Diminished intestinal motility
Correct Answer: A
Rationale: The correct answer is A: Decreased hydrochloric acid. As people age, there is a natural decline in hydrochloric acid production in the stomach, leading to decreased digestion and absorption of nutrients. This can result in digestive disorders such as malabsorption. Increased enzyme levels (B) would actually be beneficial for digestion. Inadequate chewing (C) can lead to issues like choking but is not specifically related to age. Diminished intestinal motility (D) can occur with age but is not directly linked to digestive disorders in older adults.
The submucosa of the GIT
- A. Is important for protection
- B. Helps with absorption and secretion
- C. Contains an outer and inner layer
- D. Is between the serosa and muscularis externa
Correct Answer: B
Rationale: The submucosa of the GIT is rich in blood vessels, nerves, and lymphatic vessels, aiding in absorption and secretion of nutrients and fluids. The submucosa is not primarily responsible for protection (choice A). It does not contain distinct outer and inner layers (choice C). The submucosa is located between the mucosa and muscularis externa, not the serosa (choice D). Therefore, the correct answer is B as it aligns with the known functions and characteristics of the submucosa.
The liver contains special blood channels termed _____.
- A. sinusoids
- B. central vein
- C. hepatic cells
- D. portal veins
Correct Answer: A
Rationale: The correct answer is A: sinusoids. Sinusoids are specialized blood channels found in the liver that allow for the exchange of nutrients, waste products, and toxins between hepatocytes and blood. They play a crucial role in the liver's functions of detoxification, metabolism, and storage. Central vein (B) is a vessel located in the center of liver lobules, not a blood channel. Hepatic cells (C) refer to the liver cells themselves, not blood channels. Portal veins (D) are vessels that bring blood from the digestive organs to the liver, but they are not the special blood channels within the liver.
The low pH of the stomach activates enzymes that digest ______ while inactivating enzymes that digest ______.
- A. lipids; proteins
- B. proteins; starch
- C. starch; proteins
- D. nucleic acids; starch
Correct Answer: B
Rationale: The correct answer is B because the low pH of the stomach activates pepsin, an enzyme that digests proteins, while inactivating salivary amylase, an enzyme that digests starch. Pepsin works optimally in an acidic environment, breaking down proteins into peptides. Salivary amylase, on the other hand, works best at a neutral pH and is denatured in the acidic stomach, leading to its inactivation. Choices A, C, and D are incorrect because lipids are primarily digested in the small intestine, and nucleic acids are not directly affected by the stomach's pH.