Several hormones are synthesized in the hypothalamus and transported to the anterior pituitary gland. The mechanism of transportation from hypothalamus to anterior pituitary gland is through the ________.

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: 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.

Correct Answer: C

Rationale: Rationale: 1. Oxytocin is the hormone responsible for stimulating uterine contractions during labor and delivery. 2. Oxytocin also triggers the release of milk during nursing by causing contraction of the cells around the milk-filled alveoli. 3. ADH (A) regulates water balance, glucagon (B) regulates blood sugar levels, and prolactin (D) stimulates milk production but not milk release. Summary: Oxytocin is the correct answer because it specifically stimulates uterine contractions and milk release during nursing, while the other choices are not directly related to these functions.

Correct Answer: A

Rationale: Step-by-step rationale: 1. Exophthalmic goiter refers to bulging eyes and enlarged thyroid gland. 2. Graves disease is an autoimmune disorder causing hyperthyroidism, resulting in both symptoms. 3. Hashimoto's disease is an autoimmune disorder causing hypothyroidism, not associated with exophthalmic goiter. 4. Myxedema is severe hypothyroidism but does not typically present with exophthalmic goiter. 5. Acromegaly is caused by excess growth hormone, leading to enlarged hands and feet, not related to exophthalmic goiter.