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. Prior to leaving on a backpacking trip to Southeast Asia, a college student has received a tetanus booster shot. This immunization confers protection by way of what immune process?

• A. Passive natural immunity
• B. Active natural immunity
• C. Passive artificial immunity
• D. Active artificial immunity

Correct answer: D

Rationale: The correct answer is D: Active artificial immunity. A tetanus booster shot confers protection through active artificial immunity. Active immunity involves the body producing its antibodies in response to an antigen, providing long-lasting protection. In this case, the tetanus booster shot triggers the student's immune system to produce specific antibodies against tetanus toxins. Choices A, B, and C are incorrect because passive immunity does not involve the individual's immune system producing antibodies; instead, it involves the direct transfer of antibodies from another source (natural or artificial) for immediate, but temporary, protection.

3. In which disorder does a Staphylococcus aureus organism produce a toxin leading to exfoliation and large blister formation?

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

Correct answer: B

Rationale: The correct answer is 'Herpes simplex I virus.' This disorder is known as Staphylococcal scalded skin syndrome (SSSS), where a Staphylococcus aureus organism produces an exfoliative toxin leading to skin exfoliation and large blister formation. Choices B, C, and D are incorrect. Herpes simplex viruses (I and II) cause different types of skin lesions and do not lead to exfoliation and blister formation. Necrotizing fasciitis is a severe soft tissue infection, while cellulitis is a bacterial skin infection that does not typically involve exfoliation and blister formation like in SSSS.

4. The parents of a 3-year-old boy have brought him to a pediatrician for assessment of the boy's late ambulation and frequent falls. Subsequent muscle biopsy has confirmed a diagnosis of Duchenne muscular dystrophy. Which teaching point should the physician include when explaining the child's diagnosis to his parents?

• A. Your child may develop breathing difficulties as the disease progresses.
• B. Your child is likely to benefit from physical therapy and exercise.
• C. This condition can be cured with early intervention and treatment.
• D. The disease is caused by inflammation in the muscles, which leads to weakness.

Correct answer: A

Rationale: The correct teaching point that the physician should include when explaining Duchenne muscular dystrophy to the parents is that 'Your child may develop breathing difficulties as the disease progresses.' Duchenne muscular dystrophy is a progressive condition that affects muscle strength, including respiratory muscles, leading to breathing difficulties as the disease advances. Choice B is incorrect because while physical therapy and exercise can help maintain muscle function and mobility, they do not cure the condition. Choice C is incorrect because Duchenne muscular dystrophy is a genetic disorder with no known cure. Choice D is incorrect as Duchenne muscular dystrophy is primarily characterized by a lack of dystrophin protein due to genetic mutations, not inflammation in the muscles.

5. A 20-year-old male shoots his hand with a nail gun while replacing roofing shingles. Which of the following cell types would be the first to aid in killing bacteria to prevent infection in his hand?

• A. Eosinophils
• B. Neutrophils
• C. Leukotrienes
• D. Monocytes

Correct answer: B

Rationale: Neutrophils are the first responders to bacterial infections. When there is a breach in the skin like in this scenario, neutrophils are quickly recruited to the site of injury to phagocytize and kill bacteria. Eosinophils are primarily involved in parasitic infections and allergic reactions, making choice A incorrect. Leukotrienes are lipid mediators involved in inflammation but are not cells, so choice C is incorrect. Monocytes are precursors to macrophages and play a role in immune response, but they are not the first cells to arrive at the site of a bacterial infection, making choice D incorrect.

Similar Questions