If you drank a liter of water very quickly, the result would be

Correct Answer: B

Rationale: The correct answer is B: decreased secretion of antidiuretic hormone. When you drink a liter of water quickly, it leads to a sudden increase in blood volume and a decrease in blood osmolality. This triggers the body to reduce the secretion of antidiuretic hormone (ADH) to prevent excessive water retention and maintain proper fluid balance. ADH helps in water reabsorption in the kidneys, so decreased secretion allows for more water to be excreted through urine. The other choices are incorrect because drinking water rapidly would not directly affect oxytocin secretion.

Correct Answer: C

Rationale: The correct answer is C: hypophyseal portal system. This system involves a direct blood vessel connection between the hypothalamus and the anterior pituitary gland, allowing hormones synthesized in the hypothalamus to be rapidly transported to the anterior pituitary without being diluted in the general circulation. The hepatic portal system (A) involves blood flow from the digestive system to the liver. The general circulatory system (B) would dilute the hormones before reaching the anterior pituitary. A feedback loop (D) is a mechanism that regulates hormone levels but is not the primary mode of transportation between the hypothalamus and anterior pituitary.

Correct Answer: B

Rationale: Leptin is primarily secreted by adipocytes, which are fat cells. Adipocytes play a crucial role in regulating energy balance and appetite through leptin secretion. Lymphocytes are immune cells, goblet cells secrete mucus, and fibroblasts are connective tissue cells, none of which are involved in leptin secretion.

Correct Answer: C

Rationale: The correct answer is C: hydrocortisones. Eicosanoids are signaling molecules derived from fatty acids, including prostaglandins and leukotrienes, which act as paracrines. Hydrocortisone is a steroid hormone, not an eicosanoid. It functions differently from eicosanoids, which act locally as signaling molecules. Therefore, hydrocortisones do not belong to the eicosanoid category. Choices A, B, and D are incorrect because paracrines, leukotrienes, and prostaglandins are all types of eicosanoids with specific functions in the body.

Correct Answer: D

Rationale: The correct answer is D: steroid. Steroid hormones are lipid-soluble and can pass through cell membranes easily. This property allows them to be taken orally since they are not digested in the stomach and can be absorbed in the intestines. Carbohydrates (A), peptides (B), and proteins (C) are water-soluble and cannot pass through cell membranes easily, making them unsuitable for oral administration.