Nokea
Which of the following drugs does not pass the blood-brain barrier:
- A. Ephedrine
- B. Propranolol
- C. Clonidine
- D. Guanethidine
Correct Answer: D
Rationale: The correct answer is D: Guanethidine. Guanethidine is a quaternary amine, which prevents it from passing the blood-brain barrier due to its charge. The blood-brain barrier is selective and only allows certain molecules to pass through. In contrast, choices A, B, and C (Ephedrine, Propranolol, Clonidine) are all capable of crossing the blood-brain barrier to some extent due to their chemical properties. Ephedrine is a weak base, Propranolol is lipophilic, and Clonidine is relatively small in size, allowing them to penetrate the blood-brain barrier.
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Which statement explains why elements in the same group of the Periodic Table have similar chemical properties?
- A. They have different numbers of protons.
- B. They have the same number of neutrons.
- C. They have the same number of electron shells.
- D. They have the same number of outer-shell electrons.
Correct Answer: D
Rationale: Correct Answer: D
Rationale:
1. Elements in the same group have similar outer electron configurations.
2. Outer-shell electrons determine chemical properties.
3. Having the same number of outer-shell electrons leads to similar chemical behaviors.
4. This is due to similar valence electron interactions in chemical reactions.
Summary:
A: Incorrect. Protons do not determine chemical properties in the same group.
B: Incorrect. Neutrons do not affect chemical properties in the same group.
C: Incorrect. Having the same number of electron shells does not guarantee similar chemical properties.
Why are the hormones cortisol, glucagon, epinephrine, and growth hormone referred to as counter regulatory hormones?
- A. Decrease glucose production
- B. Stimulate glucose output by the liver
- C. Increase glucose transport into the cells
- D. Independently regulate glucose level in the blood
Correct Answer: B
Rationale: Counter regulatory hormones, including cortisol and glucagon, stimulate the liver to release glucose to counteract hypoglycemia.
A patient with Graves' disease asks the nurse what caused the disorder. What is the best response by the nurse?
- A. The cause of Graves' disease is not known, although it is thought to be genetic.
- B. It is usually associated with goiter formation from an iodine deficiency over a long period of time.
- C. Antibodies develop against thyroid tissue and destroy it, causing a deficiency of thyroid hormones.
- D. In genetically susceptible persons, antibodies are formed that cause excessive thyroid hormone secretion.
Correct Answer: D
Rationale: Graves' disease is caused by antibodies stimulating the thyroid to produce excessive thyroid hormones in genetically predisposed individuals.
State what the oesophagus connects to?
- A. Throat to lungs
- B. Duodenum to gall bladder
- C. Pancreas to duodenum
- D. Throat to stomach
Correct Answer: D
Rationale: The correct answer is D: Throat to stomach. The esophagus connects the throat (pharynx) to the stomach, allowing food to pass from the mouth to the stomach for digestion. Choice A is incorrect as the esophagus does not connect the throat to the lungs. Choices B and C are also incorrect as they mention connections that do not involve the esophagus. The esophagus specifically functions to transport food and liquids from the mouth to the stomach for further digestion.
How do hormones respond following the ingestion of a high-protein, carbohydrate-free meal?
- A. Both insulin and glucagon are inhibited because blood glucose levels are unchanged.
- B. Insulin is inhibited by low glucose levels and glucagon is released to promote gluconeogenesis.
- C. Insulin is released to facilitate the breakdown of amino acids into glucose and glucagon is inhibited.
- D. Glucagon is released to promote gluconeogenesis and insulin is released to facilitate movement of amino acids into muscle cells.
Correct Answer: D
Rationale: After a high-protein, carbohydrate-free meal, glucagon promotes gluconeogenesis to maintain glucose levels, while insulin facilitates amino acid transport into muscle cells.