Nokea
Which one of the following is a cardio selective β1-blocker:
- A. Timolol
- B. Metoprolol
- C. Nadolol
- D. Sotalol
Correct Answer: B
Rationale: The correct answer is B: Metoprolol. Metoprolol is a cardioselective beta-1 blocker, meaning it primarily blocks beta-1 receptors in the heart, leading to a decrease in heart rate and contractility. This selectivity reduces the risk of bronchoconstriction compared to non-selective beta blockers like Timolol (Choice A), Nadolol (Choice C), and Sotalol (Choice D), which can also block beta-2 receptors in the lungs, potentially causing respiratory issues in patients with asthma or COPD. Therefore, Metoprolol is the best choice for patients with cardiovascular conditions who also have respiratory concerns.
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The patient with diabetes insipidus is brought to the emergency department with confusion and dehydration after excretion of a large volume of urine today even though several liters of fluid were drunk. What is a diagnostic test that the nurse should expect to be done to help make a diagnosis?
- A. Blood glucose
- B. Serum sodium level
- C. Urine specific gravity
- D. Computed tomography (CT) of the head
Correct Answer: C
Rationale: Urine specific gravity is typically low in diabetes insipidus due to excessive urine output and inability to concentrate urine.
A 33-year-old woman becomes poisoned after receiving an injection of concentrated botulinum toxin. Which of the following is the main neurochemical mechanism by which this Clostridium toxin causes its effects?
- A. Directly activates all muscarinic and nicotinic receptors
- B. Inhibits ACh release from all cholinergic nerves
- C. Prevents neuronal norepinephrine reuptake
- D. Releases norepinephrine via a nonexocytotic process
Correct Answer: B
Rationale: The correct answer is B: Inhibits ACh release from all cholinergic nerves. Botulinum toxin blocks the release of acetylcholine (ACh) from cholinergic nerve terminals, leading to muscle paralysis. This occurs through the cleavage of SNARE proteins, preventing vesicle fusion and neurotransmitter release. Choice A is incorrect because botulinum toxin does not directly activate receptors. Choice C is incorrect as botulinum toxin does not affect neuronal norepinephrine reuptake. Choice D is incorrect because botulinum toxin does not release norepinephrine via a nonexocytotic process.
Which gland is located just superior to the kidneys?
- A. Pituitary
- B. Adrenal
- C. Pancreas
- D. Ovary
Correct Answer: B
Rationale: The correct answer is B: Adrenal gland. The adrenal gland is located just superior to the kidneys. It is part of the endocrine system and plays a crucial role in producing hormones such as cortisol and adrenaline. The pituitary gland (A) is located in the brain, the pancreas (C) is situated in the abdomen, and the ovaries (D) are found in the pelvic region. The adrenal gland's location and function make it the most appropriate choice in this scenario.
Which of the following arteries supply the tail of pancreas?
- A. Inferior pancreaticoduodenal
- B. Left gastroepiploic artery
- C. Splenic artery
- D. Superior pancreaticoduodenal
Correct Answer: C
Rationale: The correct answer is C: Splenic artery. The splenic artery supplies the tail of the pancreas through its branches. The splenic artery runs along the superior border of the pancreas and gives off multiple branches that supply various parts of the pancreas, including the tail.
A: Inferior pancreaticoduodenal artery supplies the inferior part of the pancreas.
B: Left gastroepiploic artery supplies the greater curvature of the stomach.
D: Superior pancreaticoduodenal artery supplies the pancreatic head and duodenum.
Therefore, the splenic artery is the correct answer as it specifically supplies the tail of the pancreas.
An example of a hormone that under certain circumstances is regulated by positive feedback is:
- A. calcitonin.
- B. histamine.
- C. oxytocin.
- D. melatonin.
Correct Answer: C
Rationale: Rationale:
1. Oxytocin is released during childbirth to stimulate uterine contractions.
2. As contractions increase, oxytocin secretion is further stimulated in a positive feedback loop.
3. This positive feedback mechanism amplifies the contractions until delivery.
4. Calcitonin regulates calcium levels, histamine is involved in allergic responses, and melatonin regulates sleep-wake cycles.
Summary:
- Calcitonin, histamine, and melatonin do not exhibit positive feedback regulation like oxytocin during childbirth.