Final answer:
The correct phenomenon where white blood cells attach to the endothelium, lining up along the capillary walls, is termed diapedesis. It is a critical part of the immune system's response to infections, allowing cells to migrate to tissues where they are needed.The correct answer is option b.
Step-by-step explanation:
The phenomenon where white blood cells (WBCs) line up at the capillary walls and become attached to the edge of the endothelium is known as diapedesis. This process allows leukocytes, or white blood cells, to exit the bloodstream to reach sites of infection or injury. Leukocytes move through the walls of blood vessels by squeezing between adjacent cells. Their emigration, or exit from the circulation, is essential for the immune response because it enables leukocytes to reach and infiltrate infected or inflamed tissue.
Terms related to diapedesis include chemotaxis, which is the movement of cells in response to chemical stimuli. The chemicals emitted from damaged or infected cells act like a distress signal attracting leukocytes to the area that needs an immune response. This positive chemotaxis is crucial for guiding leukocytes to the site of infection or injury. Once leukocytes have left the bloodstream, they may transform into different cell types like macrophages or microglia, depending on their function.
While phagocytosis is related to the immune response, it refers to the process by which cells, like leukocytes, engulf pathogens to destroy them, which is different from diapedesis, where cells are simply moving out of the bloodstream. The correct option for the phenomenon where WBCs line up and attach to the endothelium is B) Margination.