Which of the following intravenous solutions is hypotonic?

Correct Answer: C

Rationale: A hypotonic solution has a lower concentration of solutes compared to the cells in the body. 0.45% saline is hypotonic because it has a lower concentration of sodium chloride compared to the normal extracellular fluid in the body. When this solution is administered intravenously, water will move into the cells to balance the concentration gradient, potentially causing cellular swelling. A hypotonic solution is used to rehydrate cells in cases of hypernatremia or dehydration with cellular dehydration.

Correct Answer: C

Rationale: Persistent hoarseness is often a symptom of laryngeal cancer. Laryngeal cancer affects the voice box, leading to changes in voice quality, such as hoarseness. It is important to seek medical evaluation if hoarseness lasts for more than two weeks, as early detection and treatment of laryngeal cancer can improve outcomes. Bacterial infection, aphonia (loss of voice), and peritonsillar abscess are not typically associated with persistent hoarseness as a primary symptom.

Correct Answer: D

Rationale: When auscultating the lungs of a client with pleural effusion, the examiner would note sounds consistent with fluid accumulation in the pleural space. This includes decreased or absent breath sounds over the area where the effusion is present. The presence of fluid in the involved area may cause a dullness to percussion as well. Pronounced breath sounds and expiratory wheezes are not typically associated with pleural effusion. While a friction rub may be heard in conditions such as pleurisy, it is not specific to pleural effusion.

Correct Answer: B

Rationale: An INR of 4 is higher than the normal therapeutic range for patients receiving warfarin therapy, which is typically between 2-3. An INR value above the therapeutic range indicates that the patient is at an increased risk of bleeding complications. Therefore, it is essential to report this finding to the physician for further evaluation and possible adjustment of the warfarin dosage to prevent excessive bleeding. The other values provided (A and C) are within or close to the normal ranges, so they would not warrant immediate concern compared to the elevated INR level.

Correct Answer: C

Rationale: The humoral immune response involves the activation of B cells, which are stimulated by T helper cells or macrophages. When B cells are activated, they differentiate into plasma cells that produce antibodies specific to the foreign antigen. These antibodies can neutralize pathogens, tag them for destruction by other immune cells, or activate the complement system. In addition to producing antibodies, memory B cells are also generated during this process, providing long-lasting immunity upon re-exposure to the same antigen. This coordinated response is an essential part of the adaptive immune system's defense mechanism against foreign invaders.