Regarding parathyroid glands, All the following statements are true Except:

Correct Answer: C

Rationale: The correct answer is C because the release of hormones by the parathyroid glands is actually controlled by the levels of calcium in the blood, not by the pituitary gland. A: True - Parathyroid glands are four small yellowish brown ovoid glands. B: True - They lie in relation to the posterior border of thyroid lobes. D: True - The hormone produced by the parathyroid glands, parathyroid hormone (PTH), controls blood calcium levels by stimulating the release of calcium from bones and increasing the absorption of calcium from the intestines.

Correct Answer: A

Rationale: Step-by-step rationale for choice A being correct: 1. ADH and oxytocin are peptide hormones. 2. They are synthesized in the hypothalamus. 3. They are transported and stored in the neurohypophysis. 4. Upon stimulation, they are released from the neurohypophysis. 5. Therefore, both ADH and oxytocin are indeed secreted by the neurohypophysis. Summary of why other choices are incorrect: B: ADH and oxytocin are not mineralocorticoids; they regulate water balance and uterine contractions, respectively. C: Islets of Langerhans secrete insulin and glucagon, not ADH or oxytocin. D: ADH promotes water reabsorption in the kidneys, opposite to excreting Na+ and water.

Correct Answer: D

Rationale: Rationale: 1. Insulin, cortisol, thyroxine, and oxytocin are all hormones produced by various glands in the body. 2. Insulin is produced by the pancreas, cortisol by the adrenal glands, thyroxine by the thyroid gland, and oxytocin by the hypothalamus and released by the pituitary gland. 3. Each of these hormones plays a different role in the body, such as regulating blood glucose levels, metabolism, stress response, and reproductive functions. 4. Therefore, the correct answer is D: they are all hormones. Summary: A: Incorrect. Hypothalamic-releasing hormones are specific hormones that stimulate the release of other hormones from the pituitary gland. B: Incorrect. Adenohypophysis secretes different hormones, not these specific ones. C: Incorrect. Insulin, for example, decreases blood glucose levels, while cortisol increases blood glucose levels.

Correct Answer: B

Rationale: The correct answer is B: stimulates osteoclastic activity. Parathyroid hormone (PTH) acts on bones to stimulate osteoclasts, which are responsible for breaking down bone tissue to release calcium into the bloodstream. This process helps increase blood calcium levels. Choices A, C, and D are incorrect because PTH actually increases plasma calcium levels, is not an iodine-containing hormone, and does not stimulate osteoblastic activity.

Correct Answer: C

Rationale: Ketoacidosis is most related to excess fatty acid catabolism. During this process, the body breaks down fatty acids into ketones, leading to an accumulation of ketones in the blood and causing metabolic acidosis. Adrenocortical insufficiency (A) is related to cortisol deficiency, not ketoacidosis. Cushing syndrome (B) is associated with excess cortisol production, not ketoacidosis. Hyperglycemia (D) is high blood sugar levels and is not directly related to the mechanism of ketoacidosis.