Module 5 - Infalmmation Flashcards
The inflammation process is… meaning that inflammation is responsive to…
responsible for localizing and eliminating any foreign substances,
meaning that inflammation is responsive to infections, allergies, or tissue injuries
The first line of defense in the body is…
bodily fluids, skin, and mucous membranes
Non-specific defense
The second line of defense in the body is…
the inflammatory process and phagocytosis
Non-specific defense
The third line of defense in the body is…
specific defense mechanisms
Phagocytosis
neutrophils and macrophages engulf and destroy foreign matter, pathogens, and cellular debris
Steps in the inflammation process
- Capillary and tissue cells are injured causing the release of bradykinin
- Bradykinin stimulates sensory nerve impulses that cause pain
- Pain causes mast cells and basophils to release histamine
- Bradykinin and histamine the lead capillaries to dilate, increasing blood flow and capillary permeability to the area
- Bacteria then enters the tissue causing neutrophils and monocytes to travel to the site of injury
- The neutrophils destroy the bacteria through phagocytosis with the help of their hydrolytic enzyme of their lysosomes
- Monocytes that mature into macrophages level the bloodstream and quickly become phagocytic microbes to help neutrophils.
The complement system is…
a series of enzymes releasing and following pathways to control inflammation and destroy pathogens.
This process promotes phagocytosis, increases vascular permeability, initiates chemotaxis, and cellular lysis
Platelet activation causes
prostaglandin (PG) formation,
Some of the subtypes of (PG)in turn prevents platelet and neutrophils from clustering
PG also initiates pain and febrile(fever) response
Thromboxane (one PG) is
a potent vasoconstrictor as well as platelet-aggregating agent. Initially thromboxane produces brief vasoconstriction and paleness at the injury site, creating a clot
-The effects of thromboxane are short-lived, so the area becomes red as a result of vasodilation (after vasoconstriction from thromboxane) and histamine release (from mast cells and basophils).
Leukotrienes form the slow-reacting substance of anaphylaxis (SRS-A)
causing
smooth muscle constriction of the bronchi - leads airways to narrow and increase capillary permeability and airway edema
Exudate contains
fluid and leukocytes that more from the circulation to the site of injury
Injury response - Vascular
-the local arterioles briefly undergo transient vasoconstriction to prevent the release of erythrocytes from bleeding that occurs
-then histamine and other chemicals are released that cause vasodilation
- capillaries then increase permeability and cause fluid to move from capillaries to tissue spaces
-serous fluid (containing plasma protein - mainly albumin) then becomes inflammatory exudate
-this process causes redness, heat, and swelling at the site of the injury and surrounding tissue
Injury Response - Cellular
-neutrophils and monocytes move from circulation to the site of injury due to chemotaxis (movement of a motile cell or organism, or part of one, in a direction corresponding to a gradient of increasing or decreasing concentration of a particular substance)
-Platelets move to the site of injury to promote clotting
-Neutrophils show up first (within 6-12 hours). They participate in phagocytosis to rid the area of bacteria, foreign material, and damaged cells. (neutrophils only live 24-48 hours so they start to build up at the site of injury)
-The mix of dead neutrophils, digested bacteria, and other cell debris accumulates as a creamy substance, known as pus.
-monocytes/macrophages are the second to arrive (3/7 days after onset inflammation)
-macrophages assist with phagocytosis, so the area is clean before it heals
-lymphocytes arrive last
Histamine - Chemical mediator
Found in granules of basophils, mast cells, and platelets
Causes;
Vasodilation
Increased capillary permeability
Serous fluid accumulation
Serotonin - chemical mediator
Found in platelets, mast cells, and enterochromaffin (a type of neuroendocrine cell found in the gastric glands that aid in the production of gastric acid), cells of the gastrointestinal tract
causes;
Vasodilation
Increased capillary permeability
Stimulates smooth muscle contraction
Kinins (brandykinins) - Chemical Mediator
Comes from precursor factor kininogen due to hagman factory (VII) activation from the clotting system
Causes;
Vasodilation
Increased capillary permeability
Stimulates smooth muscle contraction
Complement Components (C3a, C4a, C5a) - chamical mediator
Anaphylatoxin fragments that are produced as part of the activation of the complement system
Causes;
Stimulates the release of histamine and chemotaxis
Prostaglandins (PGs) and Leukotrienes (LTs) - chemical mediators
-Synthesized by arachidonic acid (is a precursor in the biosynthesis of prostaglandin)
-Proinflammatory
causes;
Prostaglandins cause vasodilation
Leukotrienes cause chemotaxis
Cytokines
-secreted by WMCs
-over 100 cytokines in the body
-some cytokines are beneficial to the body
-classified into interleukins, interferons, and tumor necrosis factor
Causes;
Proinflammatory mediators
Promotes b-cell production
Activates t-cells and macrophages
Acute inflammatory response
lasts 8-10 days and stops when pathogen/foreign substances are gone
Fluid that accumulates at the site of inflammation is drained by
Lymph vessels
Fever occurs due to…
cytokines release from neutrophils and macrophages