A nurse reviews labs for a client with end-stage renal disease. Which finding is expected?

Rationale:

A. Vasoconstriction of the afferent arteriole reduces blood flow into the glomerulus, which lowers glomerular filtration rate (GFR). A reduced GFR results in less filtrate formation, leading to oliguria (decreased urine output). This is a common physiologic response in conditions such as hypovolemia or acute kidney injury, where the body attempts to conserve fluid.

B. Constriction of the afferent arteriole decreases hydrostatic pressure within the glomerular capillaries, lowering filtration pressure. Glomerular pressure would actually decrease, not increase, in this scenario.

C. Increased filtrate production is incorrect. Reduced blood flow into the glomerulus decreases the amount of plasma filtered across the glomerular membrane, so filtrate production declines rather than increases.

D. Increased blood urea nitrogen (BUN) clearance is incorrect. When GFR decreases, the kidneys filter less urea, leading to elevated BUN levels in the blood. Clearance of BUN is reduced, not increased, during afferent arteriole vasoconstriction.

Rationale:

A. Regulate red blood cell production in the bone marrow is incorrect. Red blood cell production, or erythropoiesis, is controlled by erythropoietin, a hormone secreted primarily by the kidneys in response to low oxygen levels. Goblet cells have no role in this process. They are epithelial cells specialized for mucus secretion, not involved in hematopoiesis or the regulation of blood cell production.

B. Secrete mucus to trap dust and particles in the nasal cavity is correct. Goblet cells are unicellular glands located within the epithelial lining of the respiratory and gastrointestinal tracts. Their main function is to produce mucus, a sticky secretion that traps dust, microbes, and other particles, preventing them from reaching delicate tissues. In the respiratory system, mucus works together with cilia in a process called the mucociliary escalator, which moves trapped particles upward and out of the airways to maintain pulmonary health. Goblet cells also help moisturize mucosal surfaces, protecting them from drying and injury.

C. Produce antibodies to fight infections is incorrect. Antibodies are proteins produced by B lymphocytes and plasma cells as part of the adaptive immune system. Goblet cells do not have the machinery to produce immunoglobulins or participate in specific immune responses. While mucus does provide some nonspecific immune protection by trapping pathogens, it is not involved in antibody production.

D. Generate platelets for blood clotting is incorrect. Platelets are fragments of cytoplasm derived from megakaryocytes in the bone marrow and play a critical role in hemostasis. Goblet cells are unrelated to the clotting system and do not contribute to platelet formation or blood coagulation.