Acute Inflammation Flashcards
Inflammation is the reaction of blood vessels which leads to accumulation of _______ and ___________ in extravascular spaces
Fluids; leukocytes
Inflammation is fundamentally a defense mechanism in order to ___________ the initial cause of injury and the ____________ of that injury, and finally initiate _______.
Eliminate; consequences; repair
True or False: Inflammation has the potential to be more damaging to tissues than the stimulus that caused the initial damage
True
Immediate and early response to tissue injury (physical, chemical, microbiologic, etc.); occurs in seconds to minutes and last from hours to a few days
Acute inflammation
What are the outcomes of acute inflammation?
Complete resolution, healing by fibrosis, abscess formation, progression to chronic inflammation
Prolonged inflammatory response lasting weeks to years in which continuing inflammation, tissue injury, and healing (often by fibrosis) proceed simultaneously
Chronic inflammation
What is the pathologic definition of acute inflammation?
(Name the identifying components involved)
Edema, fibrin, and neutrophils
What is the pathologic definition of chronic inflammation?
(Name the identifying components involved)
Macrophages, lymphocytes, plasma cells, few neutrophils, fibrosis
What are the positive/beneficial aspects of inflammation?
- Diluting/inactivating biological & chemical toxins
- Killing/sequestering microbes, foreign material, necrotic tissue, and neoplastic cells
- Providing wound healing factors
- Restricting movement for healing/repair
What are the negative/harmful aspects of inflammation?
- Excessive/prolonged release of inflammatory mediators
- Excessive fibrosis
- Hypersensitivity and autoimmunity
- Link between chronic inflammation and neoplastic transformation
What are the two major components of acute inflammation?
Vascular changes (fluidic phase) and cellular components (cellular phase)
(Both orchestrated by many different chemical mediators!)
What is acute inflammation clinically characterized by?
(4 things)
- Heat/redness (hyperemia and vasodilation)
- Swelling (edema and emigration of leukocytes)
- Pain (chemical mediators)
- Loss of function (can preserve tissue & allow healing)
What are some causes of acute inflammation?
(Many possible answers)
Infectious bacteria/viruses/parasites, trauma, physical agents (heat/cold), toxins, tissue necrosis (any origin), foreign bodies, immunological reactions
What is the purpose of the fluidic phase of acute inflammation?
Dilute, isolate, and contain the stimulus + damage
What is the purpose of the cellular phase of acute inflammation?
Kill/digest (inactivate) the stimulus
What is the purpose of the reparative phase of acute inflammation?
Return the tissue to normal structure and function (involves movement of MQs to remove cellular debris and stimulate tissue repair)
Thin and watery and contain few cells or proteins; mechanisms include increased hydrostatic pressure, decreased osmotic pressure, and lymphatic obstruction
Transudate
Transudate that has been modified by the addition of proteins and inflammatory cells; mechanisms include endothelial damage and increased vascular permeability
Exudate
Vasoactive amines, C5a, C3a, prostaglandins, leukotrienes, PAF, IL-1, and TNF are all mediators for…
Vascular permeability (increase)
Retraction of endothelial cells, direct endothelial cell injury, and leukocyte-mediated vascular injury are all mechanisms for…
Increased vascular permeability
True or False: Retraction of endothelial cells is the least common mechanism for endothelial gap formation and very long-lived
False; this mechanism is the MOST common and rapid/short-lived
(also is mediated by vasoactive amines, NO, IL-1, and TNF)
Direct endothelial cell injury is caused by…
Burns and some microbial toxins (injury is rapid and may be long-lived)
Direct endothelial cell injury activates…
Platelets, clotting, and complement cascades
Leukocyte-mediated vascular injury is associated with…
Late stages of inflammation (injury is long-lived)
During leukocyte-mediated vascular injury, neutrophils and other leukocytes attach to endothelial cells and release _____ and _________ enzymes (from lysosomes)
ROS; proteolytic
What proteins are found in transudate and exudate, respectively?
Transudate = albumin
Exudate = fibrinogen and globulins
Presence of _______ in exudate means endothelial damage and increased vascular permeability
Fibrin
Fibrin is chemoattractant to neutrophils, which means…
Neutrophils will accumulate if inflammation does not resolve or it is exacerbated by chemical mediators (pro-inflammatory cytokines)
What are the 4 steps of the leukocyte adhesion cascade?
- Margination
- Rolling
- Activation and stable adhesion
- Transendothelial cell migration
(Process mediated by adhesion molecules and cytokines/chemokines)