Nokea
A hydrophilic medicinal agent has the following property:
- A. Low ability to penetrate through the cell membrane lipids
- B. Penetrate through membranes by means of endocytosis
- C. Easy permeation through the blood-brain barrier
- D. High reabsorption in renal tubules
Correct Answer: A
Rationale: Step-by-step rationale for why choice A is correct: Hydrophilic agents have low ability to penetrate through cell membrane lipids due to their polar nature. Lipids are hydrophobic, causing repulsion. This prevents direct diffusion of hydrophilic molecules across the lipid bilayer. This leads to the correct answer, A.
Summary of why other choices are incorrect:
B: Endocytosis involves engulfing particles into cells, not typical for small hydrophilic molecules.
C: The blood-brain barrier is selective and restricts the passage of hydrophilic substances.
D: High reabsorption in renal tubules would apply to hydrophobic agents that can pass through lipid membranes easily, not hydrophilic agents.
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Tick the amebecide drug for the treatment of an asymptomatic intestinal form of amebiasis:
- A. Chloroquine
- B. Diloxanide
- C. Emetine
- D. Doxycycline
Correct Answer: B
Rationale: The correct answer is B: Diloxanide. Diloxanide is the drug of choice for treating the asymptomatic intestinal form of amebiasis because it acts specifically against the trophozoites in the lumen of the intestine without affecting the cysts. Chloroquine (A) is used for malaria, emetine (C) is used for invasive amebiasis, and doxycycline (D) is an antibiotic not typically used for amebiasis.
Indicate the nootropic agent:
- A. Sydnocarb
- B. Eleuterococci extract
- C. Fluoxetine
- D. Piracetam
Correct Answer: D
Rationale: Step-by-step rationale:
1. Nootropic agents enhance cognitive function.
2. Piracetam is a well-known nootropic agent.
3. It improves memory, focus, and overall brain function.
4. Sydnocarb is a stimulant, not a nootropic.
5. Eleuterococci extract is an adaptogen, not a nootropic.
6. Fluoxetine is an antidepressant, not a nootropic.
Summary:
Piracetam is the correct answer as it aligns with the definition and effects of a nootropic agent. Sydnocarb, Eleuterococci extract, and Fluoxetine do not possess the specific cognitive-enhancing properties of a true nootropic agent.
Dermatitis, diarrhoea and dementia are characteristics of:
- A. Dry beriberi
- B. Pyridoxine deficiency
- C. Scurvy
- D. Pellagra
Correct Answer: D
Rationale: Step-by-step rationale for why D (Pellagra) is correct:
1. Dermatitis: Pellagra is characterized by skin rashes due to niacin deficiency.
2. Diarrhoea: Niacin deficiency in Pellagra affects the digestive system, leading to diarrhea.
3. Dementia: Niacin deficiency affects the brain, causing neurological symptoms like dementia.
Summary of why other choices are incorrect:
A: Dry beriberi is caused by thiamine (B1) deficiency, not niacin.
B: Pyridoxine deficiency (vitamin B6) does not typically present with dermatitis, diarrhea, or dementia.
C: Scurvy is caused by vitamin C deficiency and is characterized by bleeding gums, weakness, and fatigue, not the symptoms mentioned in the question.
Norepinephrine produces:
- A. Vasoconstriction
- B. Vasodilatation
- C. Bronchodilation
- D. Decresed potassium concentration in the plasma
Correct Answer: A
Rationale: Norepinephrine is a neurotransmitter that acts on alpha-adrenergic receptors causing vasoconstriction by stimulating smooth muscle contraction in blood vessels. This leads to increased blood pressure. Vasodilatation (B) is incorrect as norepinephrine does not cause blood vessels to dilate. Bronchodilation (C) is incorrect because norepinephrine primarily affects blood vessels, not bronchioles. Decreased potassium concentration in the plasma (D) is incorrect as norepinephrine does not directly impact potassium levels. Therefore, the correct answer is A: Vasoconstriction.
The constitutive COX-2 isoform tends to be homeostatic in function, while COX-1 is induced during inflammation and tends to facilitate the inflammatory response. The consideration is:
- A. TRUE
- B. FALSE
- C. None
- D. All of the above
Correct Answer: B
Rationale: The correct answer is B: FALSE. COX-1 is constitutively expressed and involved in homeostatic functions, while COX-2 is inducible during inflammation to facilitate the inflammatory response. COX-1 is responsible for maintaining normal physiological functions, such as protecting the stomach lining and regulating blood flow, while COX-2 is primarily involved in producing prostaglandins during inflammation. Therefore, COX-1 is not induced during inflammation, and COX-2 is not homeostatic. Choice A is incorrect because COX-1, not COX-2, is homeostatic. Choice C is incorrect because there is a clear distinction between the functions of COX-1 and COX-2. Choice D is incorrect because not all options are correct; only option B is accurate based on the roles of COX-1 and COX-2 in the body.