Nokea
Which of the following statements accurately describes the role of major histocompatibility complex (MHC) molecules in antigen presentation?
- A. MHC class I molecules present exogenous antigens to CD4+ T cells.
- B. MHC class I molecules present endogenous antigens to CD8+ T cells.
- C. MHC class II molecules present endogenous antigens to CD4+ T cells.
- D. MHC class II molecules present exogenous antigens to CD8+ T cells.
Correct Answer: B
Rationale: Major histocompatibility complex (MHC) class I molecules are responsible for presenting endogenous antigens, such as viral or intracellular proteins, to CD8+ T cells. These antigens are derived from within the cell, either synthesized within the cell itself or taken up from the cytoplasm. CD8+ T cells, also known as cytotoxic T cells, recognize antigens presented by MHC class I molecules and play a key role in cell-mediated immunity by destroying infected or abnormal cells.
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Which of the following structures is responsible for producing hydrochloric acid and intrinsic factor, essential for the digestion of proteins and absorption of vitamin B12, respectively?
- A. Liver
- B. Stomach
- C. Pancreas
- D. Small intestine
Correct Answer: B
Rationale: The stomach is responsible for producing hydrochloric acid and intrinsic factor. Hydrochloric acid helps in the breakdown of proteins during digestion, while intrinsic factor aids in the absorption of vitamin B12 in the small intestine. These two components are crucial for the proper functioning of the digestive system, particularly in breaking down food and absorbing essential nutrients. The liver is involved in bile production, the pancreas in the production of digestive enzymes, and the small intestine in nutrient absorption, but the specific functions related to hydrochloric acid and intrinsic factor are primarily attributed to the stomach.
A client is being prepared for a thoracentesis. The nurse should assist the client to which position for the procedure?
- A. Lying in bed on the affected side
- B. Lying in bed on the unaffected side
- C. Sims position with the head of the bed flat
- D. Prone with the head turned to the side and supported by a pillow
Correct Answer: B
Rationale: The client should be assisted to lie in bed on the unaffected side for a thoracentesis procedure. This position allows for better access to the pleural space for the insertion of a needle to aspirate the fluid or air. Gravity helps to separate the fluid or air, making it closer to the chest wall for easier removal. Additionally, this position reduces the risk of injury to the lung or other structures, as the needle is directed away from these vital structures. Lying on the unaffected side also helps in preventing potential complications and ensures the safety and effectiveness of the procedure.
A patient presents with grouped vesicles on an erythematous base, affecting the lips and perioral region. The patient reports a history of similar episodes triggered by sunlight exposure and stress. Which of the following conditions is most likely responsible for this presentation?
- A. Herpes simplex labialis (cold sores)
- B. Perioral dermatitis
- C. Angular cheilitis
- D. Allergic contact dermatitis
Correct Answer: A
Rationale: The patient's presentation with grouped vesicles on an erythematous base affecting the lips and perioral region, triggered by sunlight exposure and stress, is classic for herpes simplex labialis, commonly known as cold sores. Herpes simplex virus type 1 (HSV-1) is responsible for cold sores and is highly contagious. Recurrent episodes can be triggered by factors like UV exposure, stress, illness, and hormonal changes. Symptoms typically start with tingling or burning sensations before progressing to grouped vesicles that rupture, forming crusts. Treatment may involve antiviral medications to reduce the severity and duration of symptoms. Perioral dermatitis typically presents with papules and pustules around the mouth, while angular cheilitis involves fissures and inflammation at the corners of the mouth. Allergic contact dermatitis would present with erythema, pruritus, and possibly vesicles in
Which of the following substances has abnormal values EARLY in the course of multiple myeloma (MM)?
- A. Red blood cells
- B. White blood cells
- C. Immunoglobulins
- D. Platelets
Correct Answer: C
Rationale: In the early stages of multiple myeloma (MM), abnormal values are often seen in the levels of immunoglobulins. This is due to the abnormal proliferation of plasma cells in the bone marrow, leading to overproduction of monoclonal immunoglobulins (M proteins). These abnormal immunoglobulins can be detected in blood tests and are a key diagnostic feature of MM. Changes in red blood cells, white blood cells, and platelets are not typically early indicators of multiple myeloma.
A patient admitted to the ICU develops delirium characterized by acute onset confusion and agitation. What intervention should the healthcare team prioritize to manage the patient's delirium?
- A. Administer antipsychotic medications to reduce agitation.
- B. Implement environmental modifications to promote orientation.
- C. Refer the patient to a psychiatrist for further evaluation.
- D. Prescribe benzodiazepines for sedation and calming effect.
Correct Answer: B
Rationale: The healthcare team should prioritize implementing environmental modifications to promote orientation in a patient with delirium. Delirium is a state of acute confusion and agitation that can be triggered by various factors such as medications, infections, or metabolic disturbances. Environmental modifications involve creating a calm, quiet, and well-lit environment for the patient. Promoting proper orientation through the use of clocks, calendars, and familiar objects can help reduce confusion and improve the patient's understanding of their surroundings. These interventions are non-pharmacological and aim to address the underlying causes of delirium while minimizing the need for additional medications that may have potential side effects. Antipsychotic medications and benzodiazepines should be used judiciously and under close supervision due to the risk of adverse effects in older adults and critically ill patients. Referring the patient to a psychiatrist may be considered if the delirium is complex or if there are underlying psychiatric issues contributing to the presentation.