Nokea
Which of the following is the most plausible explanation for the protective effect of dietary fibre against cancer of the colon?
- A. Propionic acid, formed during colonic fibre fermentation inhibits liver fatty acid synthesis
- B. Butyric acid, formed during colonic fibre fermentation stimulates 'silencing' of the SLC5A8 tumour suppressor gene
- C. None of these options are correct
- D. Butyric acid, formed during colonic fibre fermentation stimulates anti-oxidant defences in the colon
Correct Answer: D
Rationale: The correct answer is D because butyric acid, a short-chain fatty acid formed during colonic fiber fermentation, has been shown to stimulate antioxidant defenses in the colon. This helps protect against oxidative damage, a key factor in the development of cancer. Choice A is incorrect because propionic acid does not inhibit liver fatty acid synthesis in relation to colon cancer. Choice B is incorrect because butyric acid does not silence the SLC5A8 tumor suppressor gene; in fact, it has been shown to have anti-tumor effects. Choice C is incorrect as there is evidence supporting the protective effect of dietary fiber through butyric acid's stimulation of antioxidant defenses.
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Which part of the digestive system is responsible for the absorption of nutrients?
- A. small intestine
- B. stomach
- C. pancreas
- D. liver
Correct Answer: A
Rationale: The correct answer is A, the small intestine, because it is the primary site for nutrient absorption in the digestive system. The small intestine is lined with villi and microvilli, increasing its surface area for efficient absorption. It contains specialized cells that transport nutrients into the bloodstream for distribution to the body. The stomach (B) primarily breaks down food using digestive enzymes and acids, while the pancreas (C) secretes digestive enzymes but does not directly absorb nutrients. The liver (D) plays a role in bile production and detoxification, but nutrient absorption occurs mainly in the small intestine.
Which of the following vitamins is fat-soluble?
- A. B12
- B. C
- C. D
- D. E
Correct Answer: C
Rationale: The correct answer is C: D. Vitamin D is fat-soluble because it can be stored in the body's fatty tissues and liver. This allows for a slower release into the bloodstream when needed. Vitamins B12, C, and E are water-soluble, meaning they dissolve in water and are not stored in the body. Vitamin B12 is stored in the liver, but it is not considered fat-soluble. Vitamin C is excreted through urine, and Vitamin E is stored in body tissues but not in fat. Therefore, the only fat-soluble vitamin among the options provided is Vitamin D.
Which action for a patient receiving enteral nutrition through a percutaneous endoscopic gastrostomy (PEG) may be delegated to a licensed practical/vocational nurse (LPN/VN)?
- A. Assessing the patient's nutritional status weekly
- B. Providing skin care to the area around the tube site
- C. Teaching the patient how to administer the feedings
- D. Determining the need for adding water to the feedings
Correct Answer: B
Rationale: The correct answer is B: Providing skin care to the area around the tube site. This task can be safely delegated to an LPN/VN because it involves basic wound care and monitoring for signs of infection or skin breakdown. LPNs/VNs are trained to provide this type of care under the supervision of a registered nurse (RN).
A: Assessing the patient's nutritional status weekly requires a higher level of assessment and interpretation of data, which is typically within the scope of an RN.
C: Teaching the patient how to administer the feedings involves patient education and requires a higher level of critical thinking and assessment skills, typically performed by an RN.
D: Determining the need for adding water to the feedings involves making clinical judgments and adjustments to the enteral nutrition plan, which should be overseen by an RN.
What is the primary function of the small intestine in the digestive system?
- A. Absorption of nutrients
- B. Mechanical digestion of food
- C. Production of digestive enzymes
- D. Storage of bile
Correct Answer: A
Rationale: The primary function of the small intestine is the absorption of nutrients. Step 1: Digestive enzymes break down food in the small intestine. Step 2: Villi and microvilli in the intestine absorb nutrients like glucose and amino acids. Step 3: Nutrients are then transported to the bloodstream for distribution to cells. Thus, choice A is correct. Choices B and C are incorrect because mechanical digestion primarily occurs in the stomach, and digestive enzymes are produced by other organs like the pancreas. Choice D is incorrect as the small intestine does not store bile; it is produced by the liver and stored in the gallbladder.
Which of the following statements is true regarding arterioles?
- A. they are less muscular than arteries, and the principle site of blood pressure regulation
- B. they are the most muscular of the major vessels, and have low blood flow velocity
- C. they are thin walled with little innervation
- D. they have no smooth muscle or connective tissue, and relatively low rates of blood flow
Correct Answer: A
Rationale: Step 1: Arterioles are smaller branches of arteries that lead to capillaries.
Step 2: Arterioles are indeed less muscular than arteries but more muscular than capillaries.
Step 3: Arterioles play a crucial role in regulating blood pressure through vasoconstriction and vasodilation.
Step 4: Choice A is correct as it accurately describes arterioles' role in blood pressure regulation.
Summary: Choice B is incorrect as arterioles are not the most muscular of major vessels. Choice C is incorrect as arterioles have significant innervation. Choice D is incorrect as arterioles do have smooth muscle and connective tissue, and they regulate blood flow efficiently.