The blood cell that can become an antibody-secreting cell is the a. lymphocyte, b. megakaryocyte, c. neutrophil, d. basophil.

Video transcript

Welcome back. Everyone. In this example, we need to determine the white blood cell that is primarily responsible for defending against bacterial and fungal infections. We've got choice. A eosinophil choice B, neutrophil C monocyte or D lymphocyte. Let's determine what the correct answer is. We're going to start by defining a eosinophil. We'll start by recalling that eosinophils are particularly effective against parasitic attacks and that's because they contain granule proteins which are able to attach to the surface of the parasite and cause damage that ultimately will eliminate any parasite present. Also recall that eosinophils are capable of producing IgE antibodies which are specific to certain allergens. So they're useful for allergic reactions in order to stimulate an immune response because the categories we've listed down do not correlate to bacterial and fungal infections. We would rule out choice A eosinophil because again, they're useful for parasitic attacks and allergic reactions. Now, we've got choice B neutrophil recall that neutrophils are a part of the innate immune system and being a part of the innate immune system means that neutrophils will have a rapid and nonspecific response to pathogens. So they're going to be involved in the early phase of the immune response. And that's because neutrophils have a biotic capability. So they're involved in phagocytosis innately and are recall able to directly engulf pathogens and eliminate them. Also recall that neutrophils have Granules that contain antimicrobial substances, which can contain protein such as neutrophil extracellular traps that can kill microbes during an immune response. And this will occur through signals activated by the presence of these bacteria and fungi in the body. And so ultimately, will place a check mark by choice B neutrophil because they have such a great and immediate response toward bacterial and fungal infections based on their innate capabilities and can be crucial in controlling and fighting against these types of infections. Now, let's move on to choice. C monocyte recall that monocytes can differentiate via chemical signals produced by cytokines or other molecules. So that allows monocytes to differentiate into either macrophages or dendritic cells where they are more active and primarily monocytes will differentiate into macrophages, which recall are also capable of phagocytosis and can engulf pathogens. However, monocytes are going to be, we we can label them as a precursor white blood cell. So overall monocytes will not be able to as quickly address bacterial and fungal infections as neutrophils will, which do not have to undergo differentiation in order to perform cytosis. So we can rule out choice c for that reason. And now moving on to choice D lymphocyte recall that lymphocytes are part of the adaptive immune system and include B and T cells. So these cells being a part of the adaptive immune system means that there is a slower immune response toward bacterial and fungal infections and the response is also more specific. So, ultimately, lymphocytes will not have an initial and direct defense towards bacterial and fungal infections due to their adaptive immune approach and ultimately will be responsible to later on clear the infection and provide long term immunity. So we want the more direct approach for the final answer and we would rule out choice D for that reason. And that leaves us with choice B neutrophil as our final answer for the white blood cell primarily responsible in the defense against bacterial and fungal infections. So I hope that this makes sense and let us know if you have any questions.