IgA is an antibody specifically designed to protect mucous membranes. Why would mucous membranes need extra protect against pathogens?

• A. Pathogens can only infect a host through portals of entry that possess mucous.
• B. Our mucous membranes are commonly exposed to substances and pathogens from the outside world.
• C. Mucous membranes have significantly fewer immune cells to control pathogens than other tissues.
• D. Mucous is built to collect foreign substances and pathogens entering the body.
• E. A and B.
• F. B and D.
• G. C and D.

Answer: (F)

Verified step by step guidance

1. Understand the role of IgA: Immunoglobulin A (IgA) is an antibody that plays a crucial role in the immune function of mucous membranes. It is the most abundant antibody in mucosal areas such as the gut, respiratory tract, and urogenital tract.
2. Identify the function of mucous membranes: Mucous membranes line various cavities in the body and cover the surface of internal organs. They are exposed to the external environment and are the first line of defense against pathogens.
3. Consider the exposure of mucous membranes: Mucous membranes are constantly exposed to potential pathogens from the outside world, such as bacteria, viruses, and other microorganisms, making them vulnerable to infection.
4. Evaluate the protective role of mucous: Mucous acts as a physical barrier that traps pathogens and foreign particles, preventing them from entering the body and causing infection.
5. Analyze the options: Given the functions and exposure of mucous membranes, options B (Our mucous membranes are commonly exposed to substances and pathogens from the outside world) and D (Mucous is built to collect foreign substances and pathogens entering the body) are correct, as they highlight the need for additional protection provided by IgA.