Which of the following leukocytes is NOT a granulocyte?

Which of the following is not involved in phagocytosis?

What is the purpose of basophils?

Which white blood cell type will notably increase during allergies and parasitic infections?

Which of the following is not a cell of innate immunity?

Which of the following describes mast cells?

The human immune system is organized along two broad arms: innate immunity and adaptive immunity. The differences between these two approaches to immunity are not always black and white, but can be described in general terms with regard to immunological memory. Adaptive immunity displays this type of memory, and mounts a more intense response to pathogens upon second and subsequent exposures.

Within adaptive immunity, the system is further divided into humoral immunity and cell-mediated immunity. We can say that antibodies are the primary mediators of the former, while CD8 T-cell based cytotoxicity is the mediator of the latter.

CD4 T-cells, unlike their CD8 counterparts, are involved in both the humoral and cell-mediated arms of adaptive immunity. These CD4 cells drive isotype switching, a process that changes the types of antibodies produced after initial exposure to a pathogen to increase their molecular affinity. Additionally, CD4 cells promote the activity of macrophages to directly digest invading pathogens.

Polymorphonuclear cells are the first cells that typically migrate to the site of infection. They are central in phagocytosing invading pathogens. Once ingested, pathogens are killed via the generation of hyper-reactive oxygen radicals. Which of the following is most likely to mediate the first step in radical oxidation in these cells?

Which of the following is involved in the innate immune system?

Which of the following cell types produces antibodies?

What is the purpose of mast cells?