Nokea
Organophosphate insecticides and nerve gases exert their lethal effects by:
- A. Blocking alpha and β-adrenergic receptors
- B. Blocking all muscarinic receptors on target cells
- C. Blocking nicotinic receptors in the brain
- D. Inhibiting acetylcholine metabolism
Correct Answer: D
Rationale: The correct answer is D because organophosphate insecticides and nerve gases inhibit acetylcholine metabolism by irreversibly binding to acetylcholinesterase enzyme, leading to accumulation of acetylcholine at synapses. This results in overstimulation of cholinergic receptors, causing symptoms of cholinergic toxicity.
Choice A is incorrect because alpha and beta-adrenergic receptors are not the targets of organophosphates. Choice B is incorrect because organophosphates do not block all muscarinic receptors. Choice C is incorrect because organophosphates do not specifically target nicotinic receptors in the brain.
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Superior mesenteric artery is …………to the neck of the pancreas and ………….to uncinate process
- A. Posterior, inferior
- B. Anterior, posterior
- C. Posterior, superior
- D. Posterior, anterior
Correct Answer: D
Rationale: The correct answer is D because the superior mesenteric artery is located posterior to the neck of the pancreas and anterior to the uncinate process. This is anatomically accurate as the artery runs behind the neck of the pancreas and in front of the uncinate process. Choice A is incorrect as it places the artery inferior to the neck of the pancreas. Choice B is incorrect as it positions the artery in front of the neck of the pancreas and behind the uncinate process. Choice C is incorrect as it suggests the artery is above the neck of the pancreas and behind the uncinate process, which is not accurate in anatomical terms.
Regarding bilirubin:
- A. unconjugated bilirubin is more soluble than conjugated
- B. all conjugated bilirubin is excreted via the intestine
- C. bile duct obstruction causes jaundice secondary to unconjugated hyperbilirubinaemia
- D. haemolytic anaemia may cause ?????? hyperbilirubinaemia
Correct Answer: D
Rationale: The correct answer is D because in hemolytic anemia, there is an increased breakdown of red blood cells, leading to excess bilirubin production. This results in unconjugated hyperbilirubinemia. Unconjugated bilirubin is less soluble than conjugated bilirubin (Choice A). Conjugated bilirubin is excreted via the bile into the intestine, but not all of it is excreted in this manner (Choice B). Bile duct obstruction typically leads to conjugated hyperbilirubinemia, not unconjugated (Choice C).
Hormones can be put into two categories based on chemical makeup. What are these categories?
- A. glands and cortex
- B. proteins and carbohydrates
- C. peptides (proteins) and steroids
- D. endocrine and ectocrine
Correct Answer: C
Rationale: The correct answer is C: peptides (proteins) and steroids. Peptides and steroids are the two main categories of hormones based on their chemical makeup. Peptides are made up of amino acids and include proteins, while steroids are derived from cholesterol. This classification is essential because it determines how hormones are synthesized and how they interact with target cells. Glands and cortex (option A) do not represent the chemical makeup of hormones, proteins and carbohydrates (option B) are broad categories that do not specifically address hormone types, and endocrine and ectocrine (option D) refer to different types of glands, not the chemical composition of hormones.
Alcohol suppresses the secretion of ______ and thus _______ the reabsorption of water from the kidneys.
- A. ADH: decreases
- B. ADH: increases
- C. aldosterone: decreases
- D. aldosterone: increases
Correct Answer: A
Rationale: The correct answer is A. Alcohol suppresses the secretion of ADH (antidiuretic hormone), which leads to a decrease in the reabsorption of water from the kidneys. ADH is responsible for increasing water reabsorption, so suppressing it results in more water being excreted. Choices B, C, and D are incorrect because alcohol does not affect aldosterone secretion, and aldosterone primarily regulates sodium reabsorption rather than water reabsorption. ADH is the hormone directly involved in water reabsorption in the kidneys, making choice A the correct answer.
Cushing syndrome and Addison’s disease are:
- A. forms of chronic adrenal cortical hypofunction.
- B. forms of chronic adrenal cortical hypersecretion.
- C. treated with replacement doses of cortisol (i.e., prednisone).
- D. disorders of the adrenal cortex.
Correct Answer: D
Rationale: The correct answer is D because both Cushing syndrome and Addison's disease are disorders of the adrenal cortex. Cushing syndrome involves excessive cortisol production, while Addison's disease is characterized by insufficient cortisol production. Both conditions directly affect the adrenal cortex, leading to hormonal imbalances.
Choice A is incorrect because Cushing syndrome involves hyperfunction, not hypofunction. Choice B is incorrect as it states hypersecretion, which is true for Cushing syndrome but not for Addison's disease. Choice C is incorrect because while replacement cortisol therapy is used for Addison's disease, it is not the only treatment option, and it does not apply to Cushing syndrome.