The following substances are considered to be referred to as eicosanoids:

Correct Answer: D

Rationale: The correct answer is D, All of the above. Eicosanoids are a group of signaling molecules derived from polyunsaturated fatty acids, primarily arachidonic acid. Prostaglandins, leukotrienes, and thromboxanes are all types of eicosanoids. Prostaglandins are involved in inflammation, pain, and fever regulation. Leukotrienes play a role in allergic and inflammatory responses. Thromboxanes are important for blood clotting and vasoconstriction. Therefore, all three choices are correct as they are all considered eicosanoids based on their chemical structure and biological functions.

Correct Answer: C

Rationale: The correct answer is C: Vitamin D. Vitamin D resembles a hormone because it acts as a hormone in the body, regulating calcium and phosphorus metabolism. It is synthesized in the skin upon exposure to sunlight, similar to hormone synthesis. Vitamin K, A, and E do not function as hormones in the body and have different roles such as blood clotting (K), vision and immune function (A), and antioxidant activity (E), respectively.

Correct Answer: A

Rationale: Correct Answer: A Rationale: 1. VLDL is a lipoprotein containing a very large proportion of lipids to protein. 2. It carries cholesterol from the liver to the tissues. 3. VLDL is a precursor to LDL, carrying triglycerides and cholesterol. 4. Choice A correctly describes the characteristics and function of VLDL. Summary: - Choice B is incorrect as it describes LDL, not VLDL. - Choice C is incorrect as it describes HDL, not VLDL. - Choice D is incorrect as it describes chylomicrons, not VLDL.

Correct Answer: A

Rationale: The correct answer is A: TRUE. Gout is indeed a familial metabolic disease characterized by acute arthritis caused by monosodium urate deposits in joints. The term "familial" indicates a genetic predisposition to the condition. Choice B is incorrect because gout is not a random occurrence but rather a metabolic disorder. Choice C, "All," is incorrect as it implies that every possible consideration about gout is true, which is not the case. Choice D, "None," is also incorrect as there are specific characteristics and features associated with gout that make it distinguishable from other conditions.

Correct Answer: C

Rationale: The correct answer is C because etidronate is actually a 1st generation biphosphonate, not a 2nd generation one. The skeletal half-life of etidronate is short, not hundreds of days like option A suggests. Bioavailability of etidronate decreases with the administered dose, making option B incorrect. In summary, etidronate is a 1st generation biphosphonate with a short skeletal half-life and decreasing bioavailability with higher doses.