ATI LPN
NCLEX Questions Gastrointestinal System Questions
Question 1 of 5
Digestion begins in the mouth. Which of the following statement is INCORRECT?
Correct Answer: D
Rationale: Correct Answer: D Rationale: 1. Digestion begins in the mouth with mechanical and chemical breakdown of food by chewing and saliva. 2. Chewing helps break down food into smaller pieces, increasing surface area for enzymes to act upon. 3. Saliva contains enzymes that start breaking down starches into sugars. 4. Chewing mixes food with saliva, aiding in the initial digestion process. 5. The statement that "digestive juices can react more easily with the food when chewed" is incorrect. Digestive juices act after food passes through the mouth and into the stomach and intestines, not in the mouth.
Question 2 of 5
The function of the cardiac sphincter is to prevent backflow of acid chyme from the
Correct Answer: B
Rationale: The correct answer is B: stomach to the esophagus. The cardiac sphincter is located between the esophagus and the stomach. Its main function is to prevent the backflow of stomach contents, including acid chyme, from the stomach back into the esophagus. This helps to protect the delicate lining of the esophagus from damage due to the acidic environment of the stomach. Explanation for other choices: A: The esophagus does not connect to the mouth, so backflow from the esophagus to the mouth is not a concern. C: The duodenum is the first part of the small intestine and is located after the stomach, so backflow to the stomach is not controlled by the cardiac sphincter. D: The colon is part of the large intestine and is not directly connected to the small intestine, so backflow from the colon to the small intestine is not relevant to the function of the cardiac sphincter.
Question 3 of 5
Where does the digestion of starch begin?
Correct Answer: C
Rationale: The correct answer is C: mouth. Starch digestion begins in the mouth with the action of salivary amylase, an enzyme that breaks down starch into maltose. This process initiates the breakdown of complex carbohydrates into simpler sugars. The stomach (A) primarily digests proteins, the small intestine (B) further breaks down carbohydrates, proteins, and fats, and the esophagus (D) is a passageway for food to travel from the mouth to the stomach. Hence, the mouth is where the digestion of starch begins due to the presence of salivary amylase.
Question 4 of 5
Which of the following contributes to the digestion of lipids?
Correct Answer: C
Rationale: The correct answer is C: gall bladder. The gall bladder stores and releases bile produced by the liver, which aids in the digestion of lipids by emulsifying fats. This process breaks down large fat globules into smaller droplets, increasing the surface area for enzymes to act upon. Salivary glands (choice A) produce saliva that contains enzymes for carbohydrate digestion. The stomach (choice B) primarily digests proteins through the action of gastric enzymes. The large intestine (choice D) mainly absorbs water and electrolytes, not involved in lipid digestion.
Question 5 of 5
The pH of various areas within the digestive tract was taken and plotted on a graph as shown above. The reading labelled X was most likely obtained from the
Correct Answer: B
Rationale: The correct answer is B: stomach. The stomach is the most acidic area in the digestive tract, with a low pH due to the presence of hydrochloric acid that aids in digestion. Choice A (mouth) has a neutral pH, not as low as the stomach. Choices C (large intestine) and D (small intestine) have higher pH levels due to the neutralization of acids from previous stages. Therefore, the reading labelled X, which is at a low pH, is most likely obtained from the stomach.