Which of the following mechanisms is responsible for the phenomenon of immunological memory, wherein the immune system mounts a faster and more robust response upon re-exposure to a previously encountered pathogen?

Correct Answer: A

Rationale: Immunological memory is primarily maintained by the clonal expansion of memory B cells. Memory B cells are a type of long-lived immune cell that originates from previously activated B cells during an immune response to a pathogen. When the immune system encounters the same pathogen again, memory B cells can quickly recognize and respond to it by undergoing rapid clonal expansion and differentiation into plasma cells that produce specific antibodies. This quick and robust response leads to the more efficient elimination of the pathogen during secondary exposure, resulting in the faster and stronger immune response characteristic of immunological memory.

Correct Answer: C

Rationale: The symptoms of polyuria (excessive urination), polydipsia (excessive thirst), and polyphagia (excessive hunger) are classic signs of diabetes mellitus. In this case, the presence of hyperglycemia (high blood sugar) and glycosuria (glucose in the urine) further support the diagnosis of diabetes mellitus. Insulin deficiency or resistance in diabetes leads to impaired glucose utilization and excessive glucose in the bloodstream, causing the classic symptoms observed in the patient. Hyperthyroidism, hypothyroidism, and Cushing's syndrome do not typically present with the hallmark symptoms of polyuria, polydipsia, and polyphagia associated with uncontrolled diabetes mellitus.

Correct Answer: C

Rationale: The patient's presentation of urinary frequency, urgency, dysuria, and suprapubic pain along with the urinalysis findings of pyuria (pus in the urine) and bacteriuria (bacteria in the urine) are highly suggestive of a urinary tract infection (UTI). UTIs are one of the most common types of bacterial infections seen in clinical practice. The symptoms described are classic for a lower urinary tract infection. The presence of pyuria and bacteriuria on urinalysis further supports the diagnosis of a UTI. Acute glomerulonephritis typically presents with hematuria, proteinuria, hypertension, and edema. Chronic kidney disease is often asymptomatic in early stages and presents with symptoms like fatigue, edema, and changes in urination later on. Renal calculi are associated with severe colicky flank pain that can radiate to the groin, and they may present with

Correct Answer: C

Rationale: Cryptosporidium parvum is a protozoan parasite that commonly causes waterborne illness characterized by watery diarrhea, abdominal cramps, and nausea. This parasite is often transmitted through contaminated water sources such as streams or lakes. Laboratory tests identifying oocysts in the stool sample are indicative of Cryptosporidium infection. Giardia lamblia can also cause similar symptoms, but the presence of oocysts points more towards Cryptosporidium in this case. Entamoeba histolytica causes amoebic dysentery with bloody diarrhea and is usually associated with fecal-oral transmission through contaminated food or water. Cyclospora cayetanensis typically causes prolonged watery diarrhea and is associated with the ingestion of contaminated food or water.

Correct Answer: A

Rationale: Opsonization refers to the process by which antibodies bind to the surface of pathogens, marking them for destruction by phagocytes or complement proteins. This coating of antibodies enhances the ability of the immune system to recognize and eliminate the pathogens effectively. Phagocytes (such as macrophages and neutrophils) are better able to engulf and digest pathogens that have been opsonized, as the antibodies attached to the pathogen surface signal to the phagocytes that they are foreign invaders. This process is crucial in the body's immune response to infections and helps in clearing pathogens from the system.

Correct Answer: D

Rationale: Taking off the room lights and drawing the window shades would provide a calm and soothing environment for the five-year-old patient admitted due to pneumonia with symptoms of cough, respiratory distress, anxiety, and dehydration. By creating a dim and quiet atmosphere, it can help reduce the child's anxiety levels, promote rest and relaxation, and potentially aid in the management of distress caused by pneumonia. Providing a quiet and dark environment can also support the child's comfort and recovery process during the hospital stay.

Correct Answer: B

Rationale: Documenting all care provided, including assessments and interventions, is the principle that should guide the nurse's documentation practices in the electronic health record (EHR). Comprehensive and accurate documentation is essential for ensuring continuity of care, communication among healthcare team members, and legal protection. By documenting all care provided, the nurse contributes to a complete and thorough picture of the patient's condition and treatment, facilitating safe and effective patient care. This principle also aligns with professional standards and regulatory requirements, emphasizing the importance of timely and complete documentation in the EHR.

Correct Answer: B

Rationale: The nurse's best response when a patient expresses frustration with the healthcare system's inefficiencies is to listen actively to the patient's concerns, acknowledge the challenges they are facing, and offer support. It is important for the nurse to validate the patient's feelings and demonstrate empathy, rather than dismissing or ignoring their frustrations. By offering support and showing understanding, the nurse can help the patient feel heard and valued, which is an essential aspect of providing patient-centered care. This approach can also help to strengthen the nurse-patient relationship and build trust, ultimately leading to better outcomes for the patient's overall healthcare experience.

Correct Answer: D

Rationale: In this scenario, the mother, who is 35 years old and illiterate but with on and off seizure, is the best candidate to sign the informed consent for a surgical procedure for the child. The mother is the primary caregiver and decision-maker for the child in most cases, and her relationship to the child is most crucial in this situation. Despite her illiteracy, she can still comprehend the importance of the procedure for her child's well-being. Additionally, accommodations can be made for an illiterate person to sign the consent form by using an "X" as a signature. It is important that the person signing the consent form has a clear understanding of the risks and benefits involved, as well as the ability to make decisions in the best interest of the child.