Acute Inflammation Flashcards
What is the purpose of Acute Inflammation?
Bring cells and molecules of host defense cells from the circulation to sites where they are needed in order to eliminate offending agents and removed damaged tissue
What does acute inflammation look like?
Redness
Heat
Swelling
Pain
Loss of Function
called the “cardinal signs”
What does Acute Inflammation do?
Rid host on initial cause of injury
remove necrotic cells tissues and debris (clean slate)
tissue repair
What are the steps to tissue repair?
Inflammation
Proliferation
Maturation
What are the steps to “Turning on” inflammation?
Recognition
Recruitment
Removal
What are the steps to “turning off” inflammation?
Regulation
Resolution
What are the cells in blood?
Red blood cells (99%)
Platelets (thrombocytes)
White blood cells (leukocytes)
What are types of white blood cells?
Neutrophils (60-70%)
Monocyte/macrophage (3-8%)
What do Sentinel Cells do?
Recognize microbes and substances
Phagocytize microbes and debris
Release Cytokines and other mediators
What are the types of Sentinel Cells?
Resident Macrophages
Dendritic cells
Mast cells
What are the inflammatory mediators?
cytokines
histamine
prostaglandins, luekotrienes
What is the function of Cytokines?
secreted by immune cells that modulate the immune response
What does it mean for a mediator to be Pro-Inflammatory?
induce fever, inflammation, tissue destruction in response to injury
what does it mean for a mediator to be anti-inflammatory?
suppress actions of pro-inflammatory
What is the function of histamine?
Vasodilation and increased capillary permeability
Where is histamine released from?
mast cells
What is the function of prostaglandins and leukotrienes?
vasodilation, pain and platelet activation
why are the prostaglandins and leukotrienes produced?
in response to cytokines
What is hemostasis?
The immediate response to prevent blood loss
What happens during hemostasis?
Damaged endothelial cells release mediators that cause vasoconstriction, platelet activation, and fibrin clot formation
What happens during vasoconstriction?
reflex vessel has to decrease flow of blood to area
What happens during Platelet Activation?
becomes sticky and begin to line up along the area of injury of the vessel; stick together and from plug to fill hole in blood vessel
What happens during fibrin clot formation?
mesh or network of fibers that interweaves the platelets in order to form a stable clot; stable clot plugs the hole and prevent the loss of blood from the blood vessel
How is injury recognized?
Sentinel cells that reside in tissues initiate response and release inflammatory mediators
How are cells recruited?
Inflammatory mediators act on local blood vessels
What happens during vasodilation?
Increase blood flow
What happens during vascular stasis?
velocity of blood flow slows down
What are vasodilation and vascular stasis responsible for?
redness
warmth
swelling
What happens during increased vessel permeability?
Histamine mediated process that makes the vessels leak and allows proteins and the cells that are in blood vessels to get out of the blood vessels into the tissues where they can have their major function
What is endothelial cell retraction?
gap between endothelial cells
What are the steps of extravasation?
roll
adhere
migrate
Which protein is used during chemotaxis?
motor protein
How is damaged tissue removed?
Neutrophils perform phagocytosis, degranulation, releasing reactive oxygen species (enzymes) and dies within 12-24 hours
Macrophages (BIG EATERS) clean up debris and release anti-inflammatory mediators
What happens during Down-regulation?
Removal of injury stimulus
short life span of neutrophils
anti-inflammatory mediators released by macrophages and other cells
What happens during Fibroblast Proliferation and migration to area of injury?
Production of collagen and ECM components
Main cell of “proliferative phase of healing
How is inflammation Regulated?
Down-regulation
Fibroblast Proliferation & Migration
How does inflammation resolve?
resolves close to original tissue
OR
pus formation (abscess), fibrosis (scar tissue); suboptimal healing response
OR
fibrosis (scar tissue); damage to tissue can’t regenerate
OR
prolonged, repetitive injury; Chronic inflammation
What can go wrong with acute inflammation?
too much: chronic inflammation
too little: delayed healing, non-healing
What happens/causes too much acute inflammation?
Prolonged, persistent or repeated injury/ infection
What happens/causes too little acute inflammation?
aging disease (diabetes, vascular disease)
inappropriate use of ant-inflammatory medication
what happens during misdirected inflammation?
attack against self tissue
What happens during mistriggered inflammation?
hypersensitive and allergies
