Chapter 7 Flashcards, Innate Immunity Inflammation and Wound Healing
(44 cards)
What are the three layers of human defense?
The three layers of human defense are barriers, innate immunity (including the inflammatory response), and adaptive (acquired) immunity.
What constitutes the first line of defense in human defense mechanisms?
The first line of defense includes physical, mechanical, and biochemical barriers as well as the normal microbiome.
What are examples of physical and mechanical barriers?
Examples include the skin and mucous membranes.
What role do antibacterial peptides play in defense?
Antibacterial peptides in mucous secretions, perspiration, saliva, tears, and other secretions provide a biochemical barrier against pathogenic microorganisms.
How does normal bacterial flora protect the body?
Normal bacterial flora protects by releasing chemicals that prevent colonization by pathogens.
What is inflammation?
Inflammation is a rapid and nonspecific protective response to cellular injury from any cause, occurring only in vascularized tissue.
What are the macroscopic hallmarks of inflammation?
The macroscopic hallmarks of inflammation are redness, swelling, heat, pain, and loss of function of the inflamed tissues.
What is the microscopic hallmark of inflammation?
The microscopic hallmark of inflammation is an accumulation of fluid and cells at the inflammatory site.
What are the three key plasma protein systems that mediate inflammation?
The three key plasma protein systems are the complement system, the clotting system, and the kinin system.
How can the complement system be activated?
The complement system can be activated by antigen-antibody reactions (classical pathway) or by bacterial polysaccharides (lectin pathway or alternative pathway).
What are the most biologically potent products of the complement system?
The most biologically potent products are C3b (opsonin), C3a (anaphylatoxin), and C5a (anaphylatoxin, chemotactic factor).
What is the function of the clotting system?
The clotting system stops bleeding, localizes microorganisms, and provides a meshwork for repair and healing.
What is the role of bradykinin in inflammation?
Bradykinin causes vascular permeability, smooth muscle contraction, and pain.
What types of cells are involved in the inflammatory process?
Cells involved include mast cells, endothelial cells, platelets, phagocytes (neutrophils, eosinophils, monocytes, macrophages, dendritic cells), natural killer (NK) cells, and lymphocytes.
What are pattern recognition receptors (PRRs)?
PRRs are expressed by most cells and recognize molecules produced by infectious microorganisms (PAMPs) or products of cellular damage (DAMPs).
What are cytokines and their role in inflammation?
Cytokines are biochemical mediators secreted by innate immune cells that activate other cells; important cytokines include interleukins, chemokines, and interferons.
What are the most important proinflammatory cytokines?
The most important proinflammatory cytokines are IL-1, IL-6, and tumor necrosis factor-alpha (TNF-α).
What is the function of interferons?
Interferons are produced by virus-infected cells and stimulate neighboring healthy cells to produce substances that prevent viral infection.
What do chemokines do?
Chemokines induce leukocyte chemotaxis.
What initiates the inflammatory response?
The mast cell is the most important activator of the inflammatory response, releasing biochemical mediators from granules and synthesizing other mediators.
What is the role of histamine in inflammation?
Histamine causes dilation of capillaries and retraction of endothelial cells, increasing vascular permeability.
How do endothelial cells regulate inflammation?
Endothelial cells regulate circulating components of the inflammatory system and maintain normal blood flow by preventing spontaneous activation of platelets and the clotting system.
What happens to endothelial cells during inflammation?
During inflammation, endothelial cells express receptors that help leukocytes leave the vessel and allow fluid to pass into tissues.
What is the role of platelets in inflammation?
Platelets interact with the coagulation cascade to stop bleeding and release mediators that promote and control inflammation.
