A major focus of the 2010 Dietary Guidelines is:

Correct Answer: B

Rationale: The correct answer is B: the unhealthy American public. The 2010 Dietary Guidelines primarily aimed to address the unhealthy eating habits prevalent in the American population. Choice A is incorrect as the focus was not solely on generally healthy segments of the population. Choice C is incorrect as the guidelines were not specifically tailored only for vulnerable population segments. Choice D is incorrect as the guidelines were more concerned with promoting healthy eating habits rather than ethnically diverse eating styles.

Correct Answer: D

Rationale: The correct answer is D: Increased awareness of personal food patterns. Keeping a food record is beneficial as it helps individuals become more mindful of their eating habits and food choices. This awareness can lead to identifying patterns, triggers, and areas for improvement in one's diet. Choices A, B, and C are incorrect because the primary benefit of keeping a food record is not about precise estimates of portion sizes, determining energy intake, or estimating supplement needs, but rather about developing a deeper understanding of personal food patterns.

Correct Answer: C

Rationale: The correct answer is C: 'muscular and chemical.' In the process of digestion, muscular movements help in mixing and propelling food along the digestive tract, while chemical breakdowns involving enzymes and acids break down food into smaller molecules for absorption. Choices A, B, and D are incorrect as thermal, segmental, and mechanical actions are not the primary actions involved in the digestion process.

Correct Answer: A

Rationale: The correct answer is A: serosa. The serosa is the outermost layer of the intestinal wall, providing a protective covering. Choice B, mucosa, is the innermost layer responsible for absorption. Choice C, submucosa, lies beneath the mucosa and contains blood vessels and nerves. Choice D, muscularis mucosae, is a smooth muscle layer located within the mucosa, helping to create folds in the intestinal lining to increase surface area for absorption.

Correct Answer: A

Rationale: The correct answer is A: Longitudinal and circular. Longitudinal and circular muscles are responsible for the movements that help propel food through the intestine. Choice B, expulsion and traction, is incorrect as these terms do not specifically relate to the types of muscular movement in the intestine. Choice C, tonus and clonus, refers to different types of muscle contractions and are not the primary movements in the intestine. Choice D, intermittent and continuous, does not accurately describe the specific types of muscular movement that occur in the intestine.