Indicate the drugs which are Ca-channel blockers influencing the brain blood flow:

Correct Answer: B

Rationale: The correct answer is B because Nimodipine and Cinnarizine are calcium channel blockers that affect brain blood flow by dilating cerebral blood vessels. Nimodipine specifically acts on cerebral arteries, while Cinnarizine works by reducing the influx of calcium ions into smooth muscle cells of the brain vasculature. Choice A, Aminalon and Picamilon, are not calcium channel blockers and do not directly influence brain blood flow. Choice C, Heparin and Warfarin, are anticoagulants and do not have a direct effect on brain blood flow through calcium channel blockade. Choice D, Vinpocetine and Nicergoline, are vasodilators that improve cerebral blood flow, but they do not act as calcium channel blockers.

Correct Answer: D

Rationale: The correct answer is D because the statement is false. The half-life of cortisol in circulation is around 60-90 minutes, not hours. Choice A is correct as cortisol is indeed synthesized from cholesterol. Choice B is correct as ACTH regulates cortisol secretion. Choice C is incorrect - most cortisol is inactivated in the liver.

Correct Answer: C

Rationale: The correct answer is C: Ethylenediamines; i.e. Suprastine. Ethylenediamines do not exhibit significant anticholinergic effects. Alkylamines, piperazines, and phenothiazines are known for their anticholinergic properties due to their chemical structures. Alkylamines have tertiary amines that cause anticholinergic effects. Piperazines have a bulky side chain that contributes to anticholinergic effects. Phenothiazines have a tricyclic structure that leads to anticholinergic activity. Therefore, C is the correct answer as ethylenediamines do not possess significant anticholinergic effects compared to the other categories.

Correct Answer: D

Rationale: The correct answer is D: Thiamine. Beri-beri is caused by a deficiency of thiamine (Vitamin B1), which is essential for energy metabolism and nerve function. Thiamine deficiency leads to symptoms like fatigue, muscle weakness, nerve damage, and heart problems. Riboflavin (A), Ascorbic acid (B), and Nicotinic acid (C) deficiencies do not directly cause Beri-beri. Riboflavin is important for energy production, Ascorbic acid is Vitamin C important for immunity, and Nicotinic acid is Vitamin B3 important for metabolism.

Correct Answer: A

Rationale: The correct answer is A because LDL is a lipoprotein that contains high amounts of cholesterol and is associated with increased risk of atherosclerosis and coronary artery disease. LDL is often referred to as beta-lipoprotein due to its density. Choice B is incorrect as it describes HDL, which contains small amounts of cholesterol and triglycerides, and is associated with a decreased risk of heart disease. It is also known as alpha-lipoprotein. Choice C is incorrect as it describes VLDL (very low-density lipoprotein), which carries most cholesterol from the liver to the tissues due to its large proportion of lipids to proteins. Choice D is incorrect as it describes chylomicrons, which are large lipoprotein particles created by the absorptive cells of the small intestine. They transport lipids to adipose tissue for breakdown by lipoprotein lipase.