Which of the following hydrolytic enzymes act in low pH?

Correct Answer: D

Rationale: The correct answer is D: Proteases. Proteases are enzymes that break down proteins, and they are known to function optimally in low pH environments, such as the acidic environment of the stomach. This is because the acidic pH helps in the activation and stability of proteases, allowing them to efficiently break down proteins into smaller peptides and amino acids. Rationale for why the other choices are incorrect: A: Peroxidases catalyze oxidation reactions and are not specifically known to act in low pH environments. B: Hydrolases are a broad category of enzymes that catalyze the hydrolysis of various molecules but are not specifically tailored for low pH conditions. C: Amylases are enzymes that break down carbohydrates and typically work best in neutral to slightly alkaline pH conditions, not in low pH environments like proteases.

Correct Answer: A

Rationale: The correct order for an abdominal assessment is inspection, percussion, palpation, and auscultation (A). Inspection allows observation of any visible abnormalities. Percussion helps assess the density of underlying structures. Palpation is performed last to avoid altering bowel sounds before auscultation. Auscultation is done last to prevent altering bowel sounds while palpating. Choices B, C, and D are incorrect because they do not follow the proper sequence for an abdominal assessment, which can lead to inaccurate findings.

Correct Answer: C

Rationale: The correct answer is C because peristalsis, the involuntary movement of the digestive tract, is controlled by both sympathetic and parasympathetic nervous systems. The parasympathetic nervous system stimulates peristalsis, while the sympathetic nervous system inhibits it. Choice A is incorrect because the somatic motor nervous system controls voluntary movements, not peristalsis. Choice B is incorrect because the sympathetic nervous system inhibits peristalsis. Choice D is incorrect because the somatic motor nervous system does not control peristalsis in the digestive tract; it controls skeletal muscle movements.

Correct Answer: C

Rationale: The correct answer is C: omental bursa. The omental bursa is a potential space located behind the stomach and in front of the pancreas, forming a cavity or pocket between the layers of mesenteries. This structure allows for movement and accommodation of the stomach during digestion. A: Visceral pleura and B: Parietal pleura are layers of the pleural membrane in the thoracic cavity, not related to mesenteries or cavity formation. D: Retroperitoneum refers to the space behind the peritoneum, not specifically forming a cavity or pocket between mesenteries.

Correct Answer: A

Rationale: The correct answer is A: lysozymes. Lysozymes in saliva help to break down bacterial cell walls, reducing the risk of gingivitis and caries. Immunoglobulin A helps to fight off harmful bacteria. Salivary amylase aids in digestion, not in preventing gingivitis or caries. Mucus and water in saliva do not directly contribute to the reduction of gingivitis or caries.