Immune System Functions and Cells

The video explains the process of phagocytosis, where phagocytes engulf pathogens and present antigens using MHC class II proteins. It highlights the role of B cells in adaptive immunity, emphasizing their specificity in recognizing pathogens. The video also discusses professional antigen presenting cells and their importance in the immune response. Finally, it introduces the concept of MHC I proteins, which will be covered in the next video.

What is the primary role of phagocytes in the immune system?

• To produce antibodies

• To engulf and digest pathogens

• To present antigens to T cells

• To activate B cells

During phagocytosis, what structure is formed around the engulfed pathogen?

• Antibody

• Phagosome

• Lysosome

• MHC complex

What is the function of lysosomes in the process of phagocytosis?

• To activate T cells

• To break down pathogens

• To present antigens

• To engulf pathogens

What are major histocompatibility complexes (MHC) responsible for?

• Engulfing pathogens

• Activating phagocytes

• Presenting antigens on cell surfaces

• Producing antibodies

Which class of MHC is involved in presenting antigens by phagocytes?

• MHC class I

• MHC class II

• MHC class III

• MHC class IV

What is the primary function of B cells in the immune system?

• To activate phagocytes

• To present antigens to T cells

• To produce antibodies

• To engulf pathogens

How do B cells recognize specific pathogens?

• Through nonspecific receptors

• By engulfing them

• Using membrane-bound antibodies

• By producing lysosomes

What happens to B cells once they are activated?

• They produce antibodies and memory cells

• They activate phagocytes

• They engulf more pathogens

• They present antigens using MHC I

What is the role of helper T cells in the activation of B cells?

• To produce antibodies

• To present antigens

• To assist in the activation process

• To engulf pathogens

What is the significance of the variable portion of B cell antibodies?

• It helps in presenting antigens

• It activates phagocytes

• It allows B cells to engulf pathogens

• It enables recognition of specific epitopes