Which is the most important safety measure when administering a medication through a patient's central venous catheter (CVC)?

Correct Answer: B

Rationale: The most important safety measure when administering a medication through a patient's central venous catheter (CVC) is ensuring the correct placement of the CVC. This is crucial to prevent complications such as extravasation, infection, or improper drug delivery. While using a sterile technique, flushing the CVC with saline after administration, and monitoring for signs of infection are all important aspects of CVC care, ensuring the correct placement of the catheter takes precedence as it directly impacts patient safety during medication administration.

Correct Answer: A

Rationale: Parathyroid hormone is the correct answer. It regulates calcium and phosphate levels in the blood by increasing calcium reabsorption in the kidneys and releasing calcium from bones. Insulin is involved in glucose metabolism, not calcium and phosphate regulation. Cortisol is a stress hormone and is not primarily responsible for regulating calcium and phosphate levels. Thyroxine is a thyroid hormone that primarily regulates metabolism, not calcium and phosphate in the blood.

Correct Answer: A

Rationale: Corrected Rationale: Graves' disease is the most common cause of hyperthyroidism. It is characterized by an overactive thyroid gland due to autoantibodies stimulating the thyroid. Hashimoto's thyroiditis is actually a cause of hypothyroidism, not hyperthyroidism. Thyroid nodules and pituitary adenoma are not common causes of hyperthyroidism.

Correct Answer: A

Rationale: The correct answer is A: 'Breaks down lactose into glucose and galactose.' Lactase is an enzyme in the small intestine that specifically breaks down lactose, the sugar found in milk, into glucose and galactose for absorption. Choice B is incorrect because proteins are broken down into amino acids by protease enzymes. Choice C is incorrect because the enzyme amylase converts starch into maltose. Choice D is incorrect as lipase enzymes break down fats into fatty acids.