2- Acute and Chronic Inflammation Flashcards
What are the 5 signs of inflammation?
Rubor (redness) Tumor (Swelling) Calor (heat) Dolor (pain) Loss of function (function laesa)- added later on
What are the 3 signs of acute inflammation?
- Increased blood flow
- Leakage of plasma proteins –> edema
- Neutrophil emigration into the tissue
What is exudate?
When plasma proteins, blood and fluids into the tissues.
What is the specific gravity of exudate?
sg > 1.020
What generally causes exudate to leak into the tissues from the blood?
increased vascular PERMEABILITY
What is transudate?
Fluid in tissues with low protein content
What is the specific gravity of transudate?
< 1.012
What generally causes transudate to enter the tissues from the blood?
An increase in vascular PRESSURE
What is the first sign of inflammation?
Vasodilation
What type of vessels dilate in the circulatory system?
Arterioles
What factors induce vasodilation?
Histamine and NO
Vasodilation leads to protein-rich fluid to squeeze through into the tissues. What type of fluid is this (transudate or exudate)?
Exudate
Why does vasodilation eventually lead to stasis?
Loss of fluid –> increased viscosity –> stasis of blood
Stasis of the blood leads to the accumulation of what important cells along the vascular endothelium?
Neutrophils
How do neutrophils enter the tissues from the blood? (generally)
The vascular endothelium expresses adhesion molecules which bind to the neutrophils, which then squeeze through and into the tissues.
What is the “hallmark” of acute inflammation?
Increased vascular permeability
What is the most common mechanism of increased vascular permeability?
Contraction of endothelial cells
Which mediators cause endothelial contraction to lead to increased vascular permeability?
Elicited by histamine, bradykinin, leukotrienes, the neuropeptide substance P, and many other mediators
Is the contraction of endothelial cells long or short lived?
Short lived (15-30mins)
How can endothelial injury cause increased vascular permeability?
Injury (by necrosis or direct injury)leads to the escape of exudate from the blood and into the tissues.
What is transcytosis?
The passage of fluid and proteins through the endothelial cell, causing exudate to build in the tissues.
Which mediator causes transcytosis?
VEGF
What happens to lymph vessels during inflammation of a tissue?
They grow and proliferate to drain the excess interstitial fluid.
What is the term when the lymph VESSEL is inflamed?
Lymphangitis
What is called when the lymph NODE is inflammed?
Lymphadenitis
Let’s go back to neutrophils going into the tissues. What causes the margination of the neutrophils to the endothelial lining?
Stasis
Which molecules cause the “rolling” of the neutrophils along the endothelium?
Selectins
Which molecules allow the adhesion of the neutrophil to the endothelium?
Integrins
Which signals cause the neutrophil to undergo diapedesis through the endothelium?
Chemokines
What causes the neutrophil attraction, once inside the tissue, to the point of injury?
Chemokines
What is the role of macrophages in repair?
They stimulate repair (fibroblast stimulation, collagen synthesis, stimulate enzymes that remodel connective tissues)
What enzymes are contained within the granules of the neutrophils?
Elastase, Defensins, Cathlicidins, and Lysozymes.
What is the protein in eosinophils that kills parasites?
Major Basic Protein (MBP)
Chediak-Higashi is a syndrome where there is a defect in what?
Phagolysosome formation
What are the symptoms of Chediak-Higashi syndrome?
Susceptibility to infections
Abnormalities in melanocytes (leading to albinism)
Cells of the nervous system (associated with nerve defects)
Platelets (causing bleeding disorders)
Leukocyte abnormalities
Neutropenia (decreased numbers of neutrophils)
Defective degranulation
Delayed microbial killing
What is defective in chronic granulomatous disease?
Phagocyte oxidase
What are the symptoms of chronic granulomatous disease?
Many granuloma formations from macrophages walling off bacteria that they cant kill
What happens in leukocyte adhesion deficiency?
Selectins and Integrins defective –> leukocyte can’t adhere to endothelium –> no leukocyte diapedesis to infected sites in tissues –> recurrent infections
Radiation and chemotherapy can cause what type of acquired leukocyte deficiency?
Bone marrow suppression