A 28-year-old woman presents with cyclic pelvic pain, dysmenorrhea, and infertility. On pelvic examination, tender nodules are palpated along the uterosacral ligaments. Which of the following conditions is most likely to be responsible for these findings?

Correct Answer: B

Rationale: Endometriosis is a chronic gynecologic condition characterized by the presence of endometrial-like tissue outside the uterus, commonly on structures within the pelvis. The classic symptoms of endometriosis include cyclic pelvic pain, dysmenorrhea (painful periods), and infertility. On pelvic examination, tender nodules or masses may be palpated along the uterosacral ligaments. These nodules are often referred to as "endometriotic implants" or "chocolate cysts." Endometriosis can cause inflammation, scarring, and adhesions in the pelvis, leading to symptoms such as pain and infertility. Polycystic ovary syndrome (PCOS) is characterized by ovarian dysfunction and hormonal imbalances, often leading to irregular periods and symptoms related to excess androgens. Adenomyosis is the presence of endometrial tissue within the myometrium of the uterus, leading

Correct Answer: C

Rationale: Humoral immunity is primarily responsible for protecting against infections by pathogens like viruses. In the case of the hepatitis B virus (HBV), the individual is exposed to the virus and develops immunity, which is typically mediated by antibodies produced by B cells. These antibodies circulate in the blood and can neutralize the virus, preventing future infections. This type of immunity is known as humoral immunity, as it involves the production of antibodies that target specific antigens, such as those present on the surface of the hepatitis B virus. In contrast, passive immunity is when antibodies are transferred from an external source, innate immunity provides immediate, non-specific defenses against pathogens, and cell-mediated immunity involves the activation of T cells to combat intracellular pathogens.

Correct Answer: A

Rationale: Plasma cells are the primary type of cells responsible for the production of antibodies during the humoral immune response. When activated by antigens, B cells differentiate into plasma cells, which are specialized in producing large quantities of antibodies. These antibodies are essential in fighting off infections by binding to antigens and marking them for destruction by other immune cells. T helper cells assist in activating B cells, but the actual production of antibodies is mainly carried out by plasma cells. Memory B cells are involved in mounting a rapid and specific secondary response upon re-exposure to the same antigen. Macrophages play a role in phagocytosis and antigen presentation, but they are not the primary cells responsible for producing antibodies during the humoral immune response.

Correct Answer: A

Rationale: Selective IgA deficiency is a primary immunodeficiency disorder characterized by low or absent levels of immunoglobulin A (IgA) in the blood. Since IgA plays a crucial role in mucosal immunity and defense against pathogens at mucosal surfaces, individuals with this deficiency are more susceptible to recurrent bacterial infections, particularly of the respiratory and gastrointestinal tracts. In contrast, severe combined immunodeficiency (SCID) is a more severe immunodeficiency disorder affecting T and B lymphocytes, chronic granulomatous disease (CGD) is a disorder of phagocytes, and autoimmune hemolytic anemia is an autoimmune disease involving red blood cells, none of which are directly associated with selective IgA deficiency.

Correct Answer: B

Rationale: In a patient experiencing an acute asthma exacerbation with severe respiratory distress and hypoxemia, the most appropriate intervention is to initiate non-invasive positive pressure ventilation (NIPPV). NIPPV can help improve ventilation, decrease work of breathing, and correct hypoxemia by providing positive pressure to keep the airways open, reduce air trapping, and increase the elimination of carbon dioxide. This intervention can help improve oxygenation and reduce the need for invasive mechanical ventilation in patients with severe asthma exacerbations. Administering high-flow oxygen via nasal cannula alone may not provide enough support for patients with severe respiratory distress. Nebulized albuterol/ipratropium combination therapy and intravenous corticosteroid therapy are also important treatments for asthma exacerbations but are not the first-line interventions for patients with severe respiratory distress and hypoxemia.