Which of the following hormones are responsible for the 'fight-or-flight' response?

Correct Answer: A

Rationale: The correct answer is A: Epinephrine and norepinephrine. These hormones are released by the adrenal glands during stressful situations to trigger the 'fight-or-flight' response. They increase heart rate, blood pressure, and energy production to prepare the body for action. Insulin and glucagon (B) regulate blood sugar levels. Estrogen and progesterone (C) are female sex hormones. Thyroxin and melatonin (D) are involved in metabolism and sleep regulation, respectively. Therefore, only A directly relates to the physiological response of 'fight-or-flight'.

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: The correct answer is B: Beta cells. Beta cells in the pancreas are responsible for secreting insulin. Insulin helps regulate blood sugar levels. Alpha cells (A) secrete glucagon, Delta cells (C) secrete somatostatin, both involved in glucose metabolism, but not insulin secretion. Choice D is incorrect as the pancreas does contain cells that secrete insulin.

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.