Nokea
Which of the following is not a change that may be caused by hormonal stimulus?
- A. a change in membrane potential
- B. the stimulation of a genetic event resulting in protein synthesis
- C. an increase in enzymatic activity
- D. direct control of the nervous system
Correct Answer: D
Rationale: The correct answer is D: direct control of the nervous system. Hormonal stimuli typically target specific cells or tissues to elicit a response, such as changes in membrane potential, genetic events leading to protein synthesis, or an increase in enzymatic activity. Hormones do not directly control the nervous system, as the nervous system operates independently and responds to its own set of stimuli. Therefore, D is the correct answer as it does not align with the typical effects of hormonal stimulation. Choices A, B, and C are incorrect as they are all changes that can be caused by hormonal stimuli.
You may also like to solve these questions
This hormone stimulates osteoclastic activity, causing bone resorption.
- A. Calcitonin
- B. Androgen
- C. PTH
- D. Thyroxine
Correct Answer: C
Rationale: The correct answer is C: PTH. Parathyroid hormone (PTH) stimulates osteoclastic activity, leading to bone resorption. PTH plays a crucial role in regulating calcium levels in the blood. When calcium levels are low, PTH is released to stimulate the release of calcium from bones through osteoclast activity.
A: Calcitonin actually inhibits osteoclastic activity, promoting bone formation.
B: Androgen is a male sex hormone and does not directly influence bone resorption.
D: Thyroxine is a thyroid hormone that regulates metabolism and does not directly affect bone resorption.
Where does the middle thyroid vein drain?
- A. Brachiocephalic vein
- B. External jugular vein
- C. Internal jugular vein
- D. Subclavian vein
Correct Answer: C
Rationale: The middle thyroid vein drains into the internal jugular vein due to its anatomical location in the neck. The internal jugular vein receives blood from the brain, face, and neck, making it a suitable drainage site for the thyroid gland. The other options (A, B, D) are incorrect because the brachiocephalic vein drains the upper body, the external jugular vein drains the scalp and face, and the subclavian vein drains the upper extremities, none of which are anatomically linked to the thyroid gland.
The beta cells of the islets of Langerhans:
- A. are the hormone-secreting cells of the adrenal cortex.
- B. are insulin-secreting pancreatic cells.
- C. secrete releasing hormones.
- D. secrete steroids.
Correct Answer: B
Rationale: The correct answer is B because beta cells of the islets of Langerhans are specialized pancreatic cells that secrete insulin, a hormone crucial for regulating blood sugar levels. Insulin helps cells absorb glucose from the bloodstream, lowering blood sugar levels. Choice A is incorrect because the hormone-secreting cells of the adrenal cortex are called adrenal cortical cells, not beta cells. Choice C is incorrect as releasing hormones are typically secreted by the hypothalamus to stimulate the pituitary gland. Choice D is incorrect because steroids are primarily secreted by the adrenal cortex, not the beta cells of the islets of Langerhans.
Which one of the following properties makes labetalol different from nearly all the other β-blockers on the market?
- A. Also blocks alpha-adrenergic receptors
- B. Causes strong atropine-like side effects, has same side effects as atropine
- C. Only blocks β1 receptors
- D. Safe for asthmatics because it lacks β2 blocking activity
Correct Answer: A
Rationale: The correct answer is A because labetalol is unique among most β-blockers as it also blocks alpha-adrenergic receptors. This dual action results in vasodilation and reduced blood pressure. Choice B is incorrect as labetalol does not cause atropine-like side effects. Choice C is incorrect as labetalol blocks both β1 and β2 receptors. Choice D is also incorrect as labetalol does have some β2 blocking activity, making it not entirely safe for asthmatics.
Which organ is responsible for synthesizing ANP?
- A. the heart
- B. the kidney
- C. the skin
- D. the spleen
Correct Answer: A
Rationale: The correct answer is A: the heart. Atrial Natriuretic Peptide (ANP) is synthesized and released by the atrial cells of the heart in response to stretching of the atrial wall due to increased blood volume or pressure. ANP functions to regulate blood pressure and fluid balance by promoting natriuresis and vasodilation. The kidney (choice B) is responsible for filtering blood and regulating electrolyte balance, but it does not synthesize ANP. The skin (choice C) is involved in thermoregulation and vitamin D synthesis, not ANP production. The spleen (choice D) plays a role in immune function and blood storage, but it does not synthesize ANP.