The germinal centers in lymph nodes are largely sites of a. macrophages, b. proliferating B lymphocytes, c. T lymphocytes, d. all of these.

Video transcript

Hi, everyone. Welcome back. Our next problem says the main processes occurring within German centers include A B cell receptor rearrangement B, proliferation and differentiation of B cells. C maturation of dendritic cells or D T cell activation. Well, let's recall that the germinal centers are in the lymph nodes. And we're looking for the main processes that occur within them. And that is choice B the proliferation and differentiation of B cells in those germinal centers, they undergo clonal expansion so rapidly generating a large number of B cells. And then they differentiate into plasma cells that produce and secrete antibodies and memory B cells responsible for that long term immunity to antigens that have been encountered. Let's look at our other answer choices to understand why they're not the correct answer. Choice. A says B cell receptor rearrangement. Well, this occurs earlier and B cell development. So it doesn't occur in the lymph nodes but occurs back in the bone marrow. So at an earlier stage in a different place, so that's why choice A isn't correct. So I see the maturation of dendritic cells. Well, dendritic cells play a critical role in this process occurring in the germinal centers, uh presenting antigens to the B cells as part of the activation of the B cell process. But the maturation of the dendritic cells themselves occurs in peripheral tissues where they encounter the antigens. So the dendritic cells are definitely involved in the processes occurring in the terminal centers. But this choice is specifically about their maturation, which does not occur there. And then finally to D T cell activation and T cell activation occurs not in the germinal centers but in the para cortex of the lymph nodes. So that's why choice D is not our correct answer. So again, the main processes occurring with the terminal centers include choice B the proliferation and differentiation of B cells. See you in the next video.