What physiologic role does calcium play in the body?

Correct Answer: A

Rationale: The correct answer is A: 'Blood clotting, transmission of nerve impulses, muscle contraction and relaxation.' Calcium plays a crucial role in various physiological functions such as blood clotting, transmission of nerve impulses, muscle contraction and relaxation, membrane permeability, and activation of certain enzymes. Choice B is incorrect because while calcium is involved in calcium homeostasis, it is not the only role it plays in the body. Choice C is incorrect as calcium indeed has several known metabolic functions, and it is not solely for preventing caries. Choice D is also incorrect as the functions mentioned are primarily carried out by other nutrients and not specifically by calcium.

Correct Answer: B

Rationale: The correct answer is B. Magnesium plays an important role in maintaining calcium homeostasis and preventing skeletal abnormalities. It is involved in more than 300 enzymatic reactions, including energy metabolism, insulin activity, and glucose use. Magnesium is vital to the structural integrity of heart muscle and other muscles and nerves. While magnesium does play a role in blood clotting, nerve impulses, muscle contraction, relaxation, ATP energy release, and metabolism of fats, carbohydrates, proteins, the primary physiologic role of magnesium in the body is related to calcium homeostasis and maintaining the structural integrity of the heart muscle. Choice A is incorrect because it includes functions of magnesium, but they are not its primary physiologic role. Choice C is incorrect as magnesium has several known metabolic functions. Choice D is incorrect because although magnesium is involved in ATP energy release and metabolism, its primary role is related to calcium homeostasis and structural integrity of muscle.

Correct Answer: A

Rationale: Wernicke-Korsakoff syndrome is indeed associated with thiamine (vitamin B1) deficiency. This syndrome is commonly seen in individuals with chronic alcoholism due to poor diet and impaired thiamine absorption. Thiamine is essential for normal brain function and energy metabolism. Riboflavin (B2) deficiency can lead to symptoms like sore throat and swollen mucous membranes, not Wernicke-Korsakoff syndrome. Niacin (B3) deficiency causes pellagra, characterized by dermatitis, diarrhea, dementia, and death, but not Wernicke-Korsakoff syndrome. Pyridoxine (B6) deficiency can result in dermatitis, glossitis, and peripheral neuropathy, but it is not associated with Wernicke-Korsakoff syndrome.

Correct Answer: D

Rationale: The oral cavity is indeed the site of various systemic disease manifestations due to multiple factors. Firstly, the rapid cellular turnover in the oral mucosa makes it susceptible to diseases. Secondly, the constant presence of microorganisms in the oral cavity contributes to the development of systemic diseases. Finally, the oral cavity being a trauma-intense environment further increases the risk of systemic manifestations. Therefore, all the provided options - rapid cellular turnover, constant attack by microorganisms, and a trauma-intense environment - play a role in making the oral cavity a site for various systemic diseases. Hence, the correct answer is 'All of the above.' Choices A, B, and C are incorrect individually as they each represent only one aspect of why the oral cavity is prone to systemic disease manifestations, whereas the correct answer encompasses all these factors.

Correct Answer: A

Rationale: Both statements are true. Systemic diseases can often present with oral manifestations before other systemic signs appear. Additionally, oral diseases can have systemic implications by affecting a person's overall health, such as through inflammation or compromised nutrient intake. Choice B is incorrect because both statements are true, as supported by medical literature. Choice C is incorrect because the second statement is also true. Choice D is incorrect because the first statement is true.