Nursing Elites

1. When educating a client about to undergo a pacemaker insertion, the nurse explains the normal phases of cardiac muscle tissue. During the repolarization phase, the nurse will stress that membranes must be repolarized before they can be re-excited. Within the cell, the nurse understands that:

• A. Potassium channels open while sodium channels close, causing repolarization to the resting state.
• B. The influx of calcium is the primary stimulus for the repolarization of cardiac tissue.
• C. Only the electrical activity within the heart will determine when repolarization occurs.
• D. The cell membranes need to stay calm, resulting in muscle tissue becoming refractory.

Correct answer: A

Rationale: During the repolarization phase of cardiac muscle tissue, potassium channels open while sodium channels close. This process is crucial for the cardiac muscle to return to its resting state after depolarization. Potassium moving out of the cell and sodium staying out helps reset the membrane potential and prepare the cell for the next depolarization phase. The influx of calcium is not the primary stimulus for repolarization in cardiac tissue; it is mainly involved in the depolarization phase. While electrical activity within the heart influences repolarization, the specific ion movements described in choice A are what physiologically drive repolarization. Cell membranes need to be in an active state during repolarization, not calm, to facilitate the necessary ion movements for muscle tissue to properly function.

2. A patient is found to have liver disease, resulting in the removal of a lobe of his liver. Adaptation to the reduced size of the liver leads to ___________ of the remaining liver cells.

• A. Metaplasia
• B. Organ atrophy
• C. Compensatory hyperplasia
• D. Physiologic hyperplasia

Correct answer: C

Rationale: Compensatory hyperplasia is the process by which the remaining cells increase in number to adapt to the reduced size of the liver. In this case, after the removal of a lobe of the liver, the remaining cells undergo compensatory hyperplasia to compensate for the lost tissue. Metaplasia refers to the reversible change of one cell type to another, not an increase in cell number. Organ atrophy is the decrease in organ size due to cell shrinkage or loss, which is opposite to an increase in cell number seen in compensatory hyperplasia. Physiologic hyperplasia is the increase in cell number in response to a normal physiological demand, not specifically due to the removal of a portion of the organ.

3. Which disorder is caused by a Staphylococcus aureus organism producing a toxin leading to exfoliation and large blister formation?

• A. Herpes simplex I virus
• B. Bullous impetigo
• C. Necrotizing fasciitis
• D. Cellulitis

Correct answer: B

Rationale: Bullous impetigo is the correct answer because it is caused by a Staphylococcus aureus toxin that leads to exfoliation and the formation of large blisters. Herpes simplex I virus (Choice A) causes cold sores and is not associated with exfoliation and blister formation. Necrotizing fasciitis (Choice C) is a severe skin infection involving the deeper layers of skin and subcutaneous tissues, typically caused by bacteria such as Streptococcus or Clostridium species, not Staphylococcus aureus. Cellulitis (Choice D) is a common bacterial skin infection, but it does not involve exfoliation and blister formation as seen in bullous impetigo.

4. A patient is administered isoniazid (INH) for tuberculosis. Which of the following adverse effects will result in discontinuation of the medication?

• A. Weight gain
• B. Jaundice
• C. Fever
• D. Arthralgia

Correct answer: B

Rationale: The correct answer is B: Jaundice. Isoniazid (INH) is known to cause hepatotoxicity, which can manifest as jaundice. Jaundice is a serious adverse effect that warrants immediate discontinuation of the medication to prevent further liver damage. Weight gain, fever, and arthralgia are not typically associated with isoniazid use and would not necessitate discontinuation of the medication.

5. Which of the following is not an autoimmune disease?

• A. Multiple sclerosis
• B. Pernicious anemia
• C. Goodpasture syndrome
• D. Transfusion reaction

Correct answer: D

Rationale: The correct answer is D, Transfusion reaction. Transfusion reaction is not an autoimmune disease because it occurs when the immune system responds to foreign blood cells, not to the body's own cells. Choices A, B, and C (Multiple sclerosis, Pernicious anemia, Goodpasture syndrome) are autoimmune diseases where the immune system mistakenly attacks the body's own tissues or organs.

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