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Which of the following statements accurately describes the role of dendritic cells in the immune response?
- A. Dendritic cells directly kill infected cells and tumor cells.
- B. Dendritic cells produce antibodies against pathogens.
- C. Dendritic cells activate na(cid:239)ve T cells and initiate adaptive immune responses.
- D. Dendritic cells release histamine and other inflammatory mediators.
Correct Answer: C
Rationale: Dendritic cells play a critical role in initiating adaptive immune responses by capturing antigens from pathogens, migrating to lymphoid organs, and presenting these antigens to naïve T cells. This activation of naïve T cells by dendritic cells is essential for the adaptive immune system to generate specific immune responses against pathogens. Dendritic cells act as professional antigen-presenting cells, which are specialized to capture, process, and present antigens to T cells, thereby facilitating the activation of T cells and the coordination of adaptive immune responses, such as the production of specific antibodies and the generation of memory T cells.
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A patient admitted to the ICU develops acute myocardial infarction (MI) with ST-segment elevation on electrocardiogram (ECG). What intervention should the healthcare team prioritize to manage the patient's MI?
- A. Perform emergent coronary angiography for revascularization.
- B. Administer fibrinolytic therapy to restore coronary blood flow.
- C. Implement strict bed rest to minimize cardiac workload.
- D. Recommend beta-blocker medications to reduce myocardial oxygen demand.
Correct Answer: A
Rationale: In a patient with acute myocardial infarction (MI) presenting with ST-segment elevation on ECG, the healthcare team should prioritize performing emergent coronary angiography for revascularization. This intervention, also known as primary percutaneous coronary intervention (PCI), involves opening up the blocked coronary artery responsible for the MI. Timely reperfusion of the affected artery is crucial in reducing myocardial damage and improving outcomes in acute MI patients. PCI is considered the preferred method for revascularization in patients with ST-segment elevation MI, as it has been shown to be more effective and associated with better outcomes compared to fibrinolytic therapy.
To help the patient with his breathing difficulty, the nurse places him in which position?
- A. Prone
- B. Sim's lateral
- C. Fowler's
- D. Supine
Correct Answer: C
Rationale: Fowler's position is the correct position to help a patient experiencing breathing difficulty. In Fowler's position, the patient is sitting up at a 45- to 60-degree angle with the legs either straight or bent. This position allows for maximum chest expansion, helping to improve ventilation and oxygenation. It is commonly used to assist patients with respiratory distress, including difficulties with breathing. Placing the patient in Fowler's position can alleviate the feeling of breathlessness and facilitate easier breathing by promoting better lung expansion.
A patient presents with gradual, painless visual field loss in both eyes, particularly in the peripheral vision. Tonometry reveals elevated intraocular pressure (IOP). Which of the following conditions is most likely responsible for this presentation?
- A. Open-angle glaucoma
- B. Closed-angle glaucoma
- C. Age-related macular degeneration
- D. Diabetic retinopathy
Correct Answer: A
Rationale: The patient presents with gradual, painless visual field loss in both eyes, particularly in the peripheral vision, which is characteristic of glaucoma. The elevated intraocular pressure (IOP) on tonometry further supports a diagnosis of glaucoma. Open-angle glaucoma is the most common type of glaucoma and typically presents insidiously with a slow progression of vision loss. In open-angle glaucoma, the drainage angle of the eye remains open but becomes less efficient over time, leading to increased intraocular pressure and optic nerve damage. This results in peripheral visual field loss. Closed-angle glaucoma, on the other hand, presents more acutely with sudden eye pain, redness, and blurred vision due to a sudden increase in intraocular pressure from a blocked drainage angle. Age-related macular degeneration and diabetic retinopathy typically do not present with elevated IOP or peripheral visual field loss.
A woman in active labor experiences irregular and ineffective uterine contractions, resulting in prolonged cervical dilation. What nursing intervention should be implemented to address this abnormal labor pattern?
- A. Encourage the mother to ambulate and change positions frequently.
- B. Administer intravenous opioids to enhance pain relief and relaxation.
- C. Initiate continuous electronic fetal monitoring to assess fetal well-being.
- D. Prepare for immediate cesarean section due to labor dystocia.
Correct Answer: A
Rationale: A woman experiencing irregular and ineffective uterine contractions with prolonged cervical dilation may indicate labor dystocia, also known as abnormal labor progression. To address this issue, the nursing intervention that should be implemented is to encourage the mother to ambulate and change positions frequently. This can help optimize fetal positioning and encourage descent through the birth canal by using gravity to aid in the progression of labor. Changing positions can also potentially improve the quality and effectiveness of contractions, leading to more successful cervical dilation and labor progress. Encouraging ambulation and position changes are non-invasive, patient-centered interventions that can be helpful in managing labor dystocia before considering more invasive interventions like cesarean section.
A patient presents with fever, headache, and a maculopapular rash that started on the face and spread to the trunk and extremities. Laboratory tests reveal leukopenia and thrombocytopenia. Which of the following is the most likely causative agent?
- A. Borrelia burgdorferi
- B. Plasmodium falciparum
- C. Rickettsia rickettsii
- D. Leishmania donovani
Correct Answer: C
Rationale: The clinical presentation described with fever, headache, maculopapular rash starting on the face and spreading to the trunk and extremities, along with leukopenia and thrombocytopenia suggests a likely diagnosis of Rocky Mountain spotted fever (RMSF), which is caused by the bacterium Rickettsia rickettsii.