Each statement is true of rickets, except one. Which is the exception?

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.

Correct Answer: D

Rationale: The correct answer is D. Calcium within saliva does not increase dental caries; in fact, the buffering action provided by calcium and phosphate in saliva inhibits caries formation by preventing the dissolution of enamel by plaque biofilm. Choice A is correct as saliva is indeed supersaturated with calcium. Choice B is correct as saliva serves as a source of calcium to mineralize an immature or demineralized enamel surface. Choice C is correct as calcium and phosphate in saliva do provide a buffering action to protect teeth from acids.

Correct Answer: A

Rationale: Both the statement and the reason are correct and related. Milk and other dairy products are indeed preferred sources of calcium because they supply most of the available calcium. Additionally, lactose present in dairy products enhances calcium absorption, making them even more efficient sources of this essential mineral. The statement correctly identifies dairy products as preferred sources of calcium, and the reason explains how lactose contributes to better calcium absorption. The other choices are incorrect as they do not accurately assess the relationship between lactose, calcium absorption, and the preference for dairy products as sources of calcium.

Correct Answer: C

Rationale: The hypothalamus, located in the middle of the brain, plays a crucial role in regulating hunger and satiety. It contains specific regions that control appetite and feeding behavior. The Medulla Oblongata (Choice A) is responsible for regulating vital functions like heartbeat and breathing, not hunger. The Pituitary Gland (Choice B) is an endocrine gland that secretes hormones but is not primarily involved in hunger regulation. The Parathyroid (Choice D) is responsible for regulating calcium levels in the body and not related to hunger or satiety.

Correct Answer: A

Rationale: The correct answer is A, Type 1 Diabetes. The prevalence of Type 1 Diabetes is seen in approximately 5% to 10% of cases. This statement highlights a key epidemiological characteristic of Type 1 Diabetes. Choice B, Type 2 Diabetes, is incorrect because the prevalence mentioned does not align with Type 2 Diabetes, which has a much higher prevalence in the general population. Choices C and D are not relevant to the question and can be disregarded.