10-8a Acute Inflammation Flashcards
What is acute inflammation?
response of vascularized tissues to infection and damage that brings cells and molecules of host defense from the circulation to sites where they are needed
What does inflammation do?
Rid host of initial cause of injury
Remove necrotic cells and tissues
Initiate the process of tissue repair
What are the cardinal signs of inflammation?
redness, heat, swelling, pain, loss of function
What drug blocks the enzyme that produces Prostaglandin E2?
non-steroidal anti-inflammatories
What does the mediator Prostaglandin E2 do?
sensitizes n. receptors to pain signals
What is a consequence to tissues swelling around a joint in regards to loss of function?
Pain and swelling limit strength, loss of motion, and neuromotor control
afferent signals go to the spinal cord and motor cortex to decrease motor drive
What are the key players in the blood (immune cells) for acute inflammation response?
platelets (thrombocytes): clotting
WBCs (leukocytes): neutrophils and monocytes (in blood)/macrophages (in tissues
What are the tissue (immune) cells related to acute inflammatory response? What are the three types?
sentinel cells
resident macrophages
dendritic cells
mast cells
What are the three key features of sentinel cells that make them useful for acute inflammatory response?
- receptor on the cell surface that detect invading microbes and the biproducts of cellular necrosis (via receptors)
- bind, ingest, and phagocytize microbes and necrotic tissue
- release cytokines and other inflammatory that recruit mediators from blood
what are cytokines?
signaling mol. produced mostly by leukocytes that respond to injury and infection by inducing/modulating immune response
What do cytokines do?
either up-regulate pro-inflammatory processes (fever, inflammation, tissue, destruction) or
suppress pro-inflammatory signals
What are histamines?
released primarily by mast cells; vascular response
vasodilation, increased capillary permeability
What are prostaglandins and leukotriens?
other mediators that are produced in response to cytokines
contribute to vasodilation, pain, and platelet activation
What is hemostasis?
immediate response to traumatic injury to prevent blood loss
What do damaged endothelial cells release? What do they cause?
mediators that cause vasoconstriction, platelet activation, and fibrin clot formation
What do activated platelets do?
stick to RBCs, each other, and the vessel wall
attract other platelets
initiate coagulation cascade = fibrin production
platelet activation + fibrin = clot
what is fibrin? What does it do?
a mesh network that stabilizes the clot
later on, fibrin mesh network provides scaffolding for infiltrating cells that eventually produce new tissue
What are the five steps of inflammation?
Recognition of injury
Recruitment of leukocytes (sentinel cells would be overwhelmed if not)
Removal of injurious agents and damaged tissue
Regulation to prevent collateral tissue damage
Resolution
How is injury recognized?
recognized by immune cells
What can trigger an inflammatory response?
trauma, necrotic tissue, infection by pathogens or foreign bodies, maladaptive immune response
What cells initally detect injury?
leukocytes in blood stream and sentinel cells in the tissue