Mineralcorticoids

Correct Answer: D

Rationale: 1. Mineralocorticoids are hormones produced in the adrenal cortex (A). 2. They are steroid hormones (B) that specifically regulate sodium and potassium homeostasis (C). 3. Therefore, the correct answer is D, as mineralocorticoids encompass all these characteristics. Other choices are incorrect as they do not fully encompass the functions and characteristics of mineralocorticoids.

Correct Answer: B

Rationale: Step-by-step rationale for why choice B is correct: 1. Hypersecretion of cortisol is a hallmark of Cushing's syndrome. 2. Excessive cortisol levels can lead to symptoms like weight gain, high blood pressure, and muscle weakness. 3. Cushing's syndrome is characterized by an overactive adrenal gland producing too much cortisol. 4. Addison's disease (choice A) is caused by adrenal insufficiency, leading to low cortisol levels. 5. Acromegaly (choice C) is a growth hormone disorder, not related to cortisol. 6. Dwarfism (choice D) is typically due to growth hormone deficiency, not cortisol excess. Summary: Choice B is correct because hypersecretion of cortisol is specifically associated with Cushing's syndrome, causing a range of symptoms related to excess cortisol production. Choices A, C, and D are incorrect as they are not directly related to cortisol hypersecretion.

Correct Answer: B

Rationale: The correct answer is B: cellular mutations occur. Hormones typically act through binding to specific receptors on target cells to initiate a signaling cascade. This process does not involve inducing mutations in the cell's DNA. Plasma membrane permeability changes, enzyme activation/inactivation, and stimulation of mitosis are all well-established mechanisms of hormone action. Therefore, B is the correct answer as it does not align with the usual mechanisms by which hormones exert their effects.

Correct Answer: B

Rationale: The correct answer is B because the endocrine system releases hormones into the bloodstream, allowing them to reach all parts of the body simultaneously and produce widespread responses. In contrast, the nervous system sends signals through nerve cells, which can only target a small number of specific cells. This difference in distribution and reach of signals is a key distinction between the endocrine and nervous systems. Choice A is incorrect because a single hormone can indeed target multiple responses in different parts of the body, similar to how a nerve signal can affect multiple cells along its path. Choice C is incorrect as nerve cells and the endocrine system can interact and influence each other's functions, such as in the case of stress response involving both systems. Choice D is incorrect because endocrine hormones can have broad effects on various organs and tissues, not limited to a small number of precise responses.

Correct Answer: A

Rationale: Step-by-step rationale: 1. Dopamine and homovanillic acid are neurotransmitters. 2. Neuroblastoma is a type of cancer that originates in neuroblasts, which are immature nerve cells. 3. Neuroblastoma can produce neurotransmitters like dopamine and homovanillic acid. 4. Therefore, dopamine and homovanillic acid are secreted in neuroblastoma. Summary: - Choice A is correct as neuroblastoma can secrete dopamine and homovanillic acid. - Choices B and C are incorrect as they are unrelated to the secretion of these neurotransmitters.