lecture 20 quiz- immunology

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What is the primary function of the mucus layer in the gastrointestinal immune system?

To support the growth of commensal bacteria

To provide a physical barrier against pathogens

To trap and eliminate dietary molecules

To contain antimicrobial molecules to inhibit microbial growth (correct)

Which type of immune cell is found in the lamina propria of the gastrointestinal tract?

Dendritic cells

Regulatory T cells (correct)

Natural killer cells

Neutrophils

What is the primary role of IgA antibodies in the gastrointestinal immune system?

To opsonize pathogens for phagocytosis

To neutralize toxins

To activate the complement system

To prevent the entry of pathogens and toxins into the body (correct)

What is the primary function of Peyer's patches in the gastrointestinal immune system?

To coordinate the adaptive and innate immune responses Signup and view all the answers

What is the primary function of regulatory T cells (Tregs) in the gastrointestinal immune system?

To suppress the immune response against commensal bacteria Signup and view all the answers

What is the term used to describe the collection of lymphoid tissues associated with the gastrointestinal tract?

Gut-associated lymphoid tissue (GALT) Signup and view all the answers

Which type of cells residing in the lamina propria are crucial phagocytic cells that engulf and eliminate invading pathogens?

Macrophages Signup and view all the answers

What do inflammatory mediators released by innate immune cells promote at the site of inflammation?

Enhanced phagocytosis Signup and view all the answers

Which type of cells play a role in immune surveillance and cytotoxicity?

Natural Killer (NK) cells Signup and view all the answers

What type of peptides are secreted by epithelial cells and immune cells in the GI tract to contribute to the maintenance of microbial balance?

Antimicrobial Peptides (AMPs) Signup and view all the answers

Which immune cells migrate to secondary lymphoid organs to initiate adaptive immune responses after sampling luminal antigens?

Dendritic cells Signup and view all the answers

What do PRRs trigger when activated by pathogens, leading to the recruitment of immune cells to the site of infection?

Production of chemokines Signup and view all the answers

What is the main challenge faced by the GI immune system?

Balancing protection against pathogens and tolerance to commensals and dietary antigens Signup and view all the answers

Which condition can result from excessive inflammation in the gut according to the text?

Inflammatory bowel disease (IBD) Signup and view all the answers

What role does IgA production play in the gut immune system?

Helps maintain tolerance to dietary antigens Signup and view all the answers

Why is balancing immune responses crucial according to the text?

To prevent opportunistic infections Signup and view all the answers

What is the consequence of a compromised immune system regarding commensal microbes?

Opportunistic infections by commensals Signup and view all the answers

How does the GI immune system handle the delicate balance mentioned in the text?

By regulating its responses to prevent inflammation-related damage Signup and view all the answers

Which cells are responsible for secreting defensins in the gastrointestinal immune system?

Paneth cells Signup and view all the answers

What is the main function of mucus secreted by goblet cells in the GI immune system?

Acting as a physical barrier against pathogens Signup and view all the answers

Which type of receptor recognizes pathogen-associated molecular patterns (PAMPs) in the GI immune system?

Toll-like receptors (TLRs) Signup and view all the answers

What is the role of tight junctions between enterocytes in the gastrointestinal immune system?

Preventing microbial translocation Signup and view all the answers

Which component forms the physical barrier that prevents microorganisms from entering underlying tissues in the GI immune system?

Basement membrane Signup and view all the answers

Which specialized cells produce mucus in the gastrointestinal immune system?

Goblet cells Signup and view all the answers

What is the primary function of Immunoglobulin A (IgA) antibodies in the gut-associated immune system?

To neutralize toxins and prevent pathogen attachment to epithelial cells Signup and view all the answers

Which of the following statements about regulatory T cells (Tregs) in the gut-associated immune system is correct?

Tregs help maintain immune tolerance and prevent autoimmunity in the gut Signup and view all the answers

Which of the following is a key function of the gut-associated immune system?

Maintaining a balance between immune tolerance and protective immunity Signup and view all the answers

What is the primary site of IgA production in the gut-associated immune system?

Peyer's patches Signup and view all the answers

Which of the following statements about the role of IgA antibodies in the gut-associated immune system is incorrect?

IgA antibodies activate the complement system and promote inflammation Signup and view all the answers

Which of the following cell types is primarily responsible for the production of IgA antibodies in the gut-associated immune system?

Plasma cells Signup and view all the answers