Chapter 11 AI generated Flashcards
Describe the role of memory B and T cells in the immune system.
Memory B and T cells are more effective defenders compared to their naive forms. They are more specific, easier to activate, and have undergone processes like class switching and somatic hypermutation.
Define intestinal microbiota and its importance in the gastrointestinal system.
Intestinal microbiota refers to the diverse microbes present in the gastrointestinal system, including commensal bacteria. They aid in digestion, produce vitamins, and protect against pathogenic bacteria.
How does the mucus in the small intestine contribute to the intestinal immune system?
The mucus acts as a diffusion barrier containing antibacterial peptides and antimicrobial proteins. It is produced by goblet cells, provides energy in the form of short-chain fatty acids, and helps prevent pathogenic bacteria from adhering to epithelial cells.
What is the role of macrophages in the intestinal immune system?
Macrophages in the lamina propria intercept bacteria, cause inflammation, and phagocytose invaders. They play a crucial role in responding to threats and maintaining immune balance in the intestines.
Describe the function of IgA in the intestinal immune system.
IgA produced by B cells in the lamina propria binds to microbes, preventing their adherence to epithelial cells. It facilitates the elimination of microbes via feces without causing inflammation.
How is IgA production in the intestinal immune system regulated?
IgA production can be driven by retinoic acid produced by dendritic cells. This regulation ensures the targeted binding of IgA to invaders and their disposal from the intestines.
Describe the role ofina propia in the immune system.
Lamina propia is where iTreg cells reside, influenced by cytokines like TGFB from healthy epithelial cells to regulate mucosal immune responses.
What is the function of Th17 cells in the intestinal immune defense?
Th17 cells are highly inflammatory and produce IL-17 to recruit neutrophils, strengthen the intestinal barrier, and enhance mucus production.
Define the role of dendritic cells (DCs) in the immune system.
DCs in lamina propia and Peyer’s patches help maintain the balance between gentle and heavy inflammatory responses by interacting with antigens and monitoring for abnormalities.
How do DCs in the intestine respond to abnormalities?
DCs detect an issue, they produce IL-6, leading to the differentiation of Th cells into Th17 cells, contributing to the immune response.
Describe the differentiation process of myeloid stem cells.
Myeloid stem cells give rise to various blood cells like erythrocytes, platelets, eosinophils, basophils, mast cells, neutrophils, monocytes (which become macrophages or dendritic cells).
Explain the origin and types of lymphoid stem cells.
Lymphoid stem cells differentiate into B cells, NK cells, and T cells, including subsets like Th cells, CTLs, NKT cells, and various B cell types.
