Located in the middle of the brain, what organ is responsible for satiety and hunger?
- A. Medulla Oblongata
- B. Pituitary Gland
- C. Hypothalamus
- D. Parathyroid
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.
You may also like to solve these questions
Each statement is true of vitamin K, except one. Which is the exception?
- A. Vitamin K is produced in the gut.
- B. Vitamin K functions as a catalyst for the synthesis of blood-clotting factors.
- C. Vitamin K maintains prothrombin levels.
- D. Vitamin K absorption increases with high levels of vitamin E supplementation.
Correct Answer: D
Rationale: The correct answer is D. Vitamin K absorption decreases with high levels of vitamin E supplementation because in larger amounts, vitamin E acts as an anticoagulant. Vitamin K is not produced in the gut but can be obtained from food sources or supplements. Vitamin K is essential for the synthesis of blood-clotting factors and is crucial in maintaining prothrombin levels, which is vital for proper blood clotting. The incorrect choice, D, is misleading as high levels of vitamin E supplementation hinder vitamin K absorption due to its anticoagulant properties. Dental hygienists should be aware of the importance of vitamin K in blood clotting, especially when treating patients who are on anticoagulant medications for conditions like stroke prevention.
Each of the following is a function of vitamin A, except one. Which is the exception?
- A. Prevention of night blindness
- B. Growth of soft tissues and bone
- C. Maintenance of more than 200 genes
- D. Integrity of body openings and their linings
Correct Answer: C
Rationale: The correct answer is C. Maintenance of more than 200 genes is not a function of vitamin A; instead, it is a function of Vitamin D. Vitamin A plays a crucial role in the prevention of night blindness by aiding in the production of the visual pigment rhodopsin. It also supports the growth of soft tissues and bone, as well as the integrity of body openings and their linings. Choice C is incorrect because the maintenance of genes is primarily associated with Vitamin D, not Vitamin A.
Which consumption pattern of fermentable carbohydrate is considered most cariogenic?
- A. A single exposure to a large quantity
- B. A single exposure to a small quantity
- C. Multiple exposures of small quantities
- D. Multiple exposures followed by chewing sugarless gum
Correct Answer: C
Rationale: Multiple exposures of small quantities are considered most cariogenic. The total amount of dietary fermentable carbohydrate seems to matter less than the form and frequency in which it is consumed. Having multiple exposures of even small quantities of fermentable carbohydrate throughout the day promotes a highly cariogenic environment in the mouth. Choices A and B, involving single exposures, are less cariogenic as they do not sustain the fermentation process over time. Choice D suggests a beneficial practice by chewing sugarless gum after exposures, which can reduce the risk, making it less cariogenic compared to multiple exposures of small quantities.
Increasing the variety of foods often prevents nutrient excesses and toxicities. A dietary change to eliminate or increase intake of one specific food or nutrient usually alters the intake of other nutrients.
- 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: D
Rationale: The first statement is false because increasing the variety of foods actually helps prevent nutrient excesses and toxicities. The second statement is true because making a dietary change to eliminate or increase the intake of a specific food or nutrient often leads to alterations in the intake of other nutrients. Choice A is incorrect because the first statement is false. Choice B is incorrect because the second statement is true. Choice C is incorrect because the first statement is false, even though the second statement is true.
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.