Nokea
What physiologic role does calcium play in the body?
- A. Blood clotting, transmission of nerve impulses, muscle contraction and relaxation
- B. Calcium homeostasis, structural integrity of heart muscle
- C. No known metabolic function, caries-preventing properties
- D. ATP energy release; metabolism of fats, carbohydrates, proteins; regulates acid-base balance.
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.
You may also like to solve these questions
Each of the following describes the physiologic roles of water, except one. Which is the exception?
- A. Acts as a solvent for chemical reactions.
- B. Maintains stability of body fluids.
- C. Enables transport of nutrients and excretion of waste.
- D. Regulates temperature by pooling as perspiration on skin.
Correct Answer: D
Rationale: The correct answer is D. Water regulates body temperature by evaporating as perspiration from the skin, not by pooling. When sweat evaporates from the skin, it takes away heat, which helps cool the body. Choices A, B, and C are correct because water acts as a solvent for chemical reactions, maintains the stability of body fluids, and enables the transport of nutrients and excretion of waste, respectively.
Each statement is true of rickets, except one. Which is the exception?
- A. Rickets is being diagnosed more frequently in the United States.
- B. Rickets is caused by vitamin C deficiency.
- C. Tachetic deformities such as bow legs or knock-knees develop.
- D. A narrow and distorted chest occurs.
Correct Answer: B
Rationale: Rickets is caused by vitamin D deficiency, not vitamin C deficiency. It usually occurs in children who are 1 to 3 years old. The name rickets came from the word 'wrikken,' meaning 'to bend or twist.' Common manifestations of rickets include tachetic deformities like bow legs or knock-knees, a narrow and distorted chest, and failure of the epiphyses of bones to develop normally, resulting in twisted and warped bones. While the diagnosis of rickets may be increasing in the United States, it is not caused by a lack of vitamin C.
Complex carbohydrates contain more than 10 monosaccharides. Complex carbohydrates are also called disaccharides.
- A. Both statements are true.
- B. Both statements are false.
- C. The first statement is true; the second is false.
- D. The first statement is false; the second is true.
Correct Answer: C
Rationale: The first statement is true; the second is false. Complex carbohydrates are also called polysaccharides and contain more than 10 monosaccharides. Choice A is incorrect because the second statement is false. Choice B is incorrect because the first statement is true. Choice D is incorrect because the second statement is false.
The RDA for iron is higher in premenopausal women than for men or postmenopausal women because of the blood loss during menstruation.
- A. Both the statement and the reason are correct and related.
- B. Both the statement and the reason are correct but are not related.
- C. The statement is correct, but the reason is not correct.
- D. The statement is not correct, but the reason is correct.
Correct Answer: A
Rationale: Both the statement and the reason are correct and related. The Institute of Medicine (IOM) recommends 18 mg of iron per day for women 19 to 50 years old, 8 mg/day for women 51 years old and older, and men 19 years old and older. During menstruation, women lose blood containing iron, leading to a higher iron requirement in premenopausal women compared to men or postmenopausal women. This increased demand aims to replenish the iron lost during this physiological process. Therefore, the statement and reason are directly linked, explaining why the RDA for iron is higher in premenopausal women than in men or postmenopausal women. Choices B, C, and D are incorrect as they do not accurately assess the relationship between the statement and the reason provided in the question.
The nutrient facts panel was established by the USDA and the FDA to improve health and well-being by enhancing nutritional knowledge. Nutrient content claims describe a relationship between a food or food component and reduced risk of a disease or health-related condition.
- A. Both statements are true.
- B. Both statements are false.
- C. The first statement is true; the second is false.
- D. The first statement is false; the second is true.
Correct Answer: C
Rationale: The correct answer is C. The first statement is true as the nutrient facts panel was indeed established by the USDA and the FDA to improve health and well-being by enhancing nutritional knowledge. However, the second statement is false. Nutrient content claims actually refer to the amount of a nutrient in a food, not to the relationship between a food and disease risk. Therefore, the second statement is incorrect, making choice C the correct option. Choice A is incorrect because the second statement is false. Choice B is incorrect as the first statement is true. Choice D is incorrect because the second statement is false.