Inflammation & Repair: body response to injury Flashcards
What are the main components of inflammation (2)?
Vascular changes
Cellular changes
Explain the 2 types of vascular changes in inflammation
Hemodynamic changes
-transient vasoC followed by vasoD (via vascular smooth muscle)
It causes hyperemia: increased blood flow
Increased permeability -mostly venous end of capi = leakage of exudate = increase osmotic pressure = « »blood viscosity = diminution of blood velocity (flow)
Increased permeability is d/t what (3)?
Endothelial cell damage
« » contraction
Leakage of new small blood vessels during repair
What is exudate
Prot-rich fluid and some blood cells out of the circulation
Where mast cells are located?
Around the capillaries
Mast cells are a source pf what?
Vascular mediators
Histamine
In acute inflammation, mast cells release
Histamine
Describe the effect of histamine in the inflammation process
VasoD
Increased permeability of venou capillaries
Responsible for que QUICK/TRANSIENT change in permeability
An increased in permeability may be delayed in what case?
Sunburn
What are the steps of cellular changes in the inflammation process (4)?
MARGINATION
Accumulation of leukocytes along blood vessel walls at the site of injury
ROLLING
ADHESION
DIAPEDESIS
What is the role of chemokines in the inflammatory process (cellular change)?
Attract immune cells toward the site of injury
Travel toward the high concentration of chemokines = chemotaxis
Name different times where chemotaxis is use (3)
Bacterial peptides
Complement
Leukotrienes
Which adhesion molecule is used in rolling?
Selectin (it is on the endothelial layer)
Which adhesion receptor is use in adhesion?
Integrin (it is on the endothelial layer and on the leukocytes)
PAF receptor binding activates integrins on leukocytes.
Then able to bind to ICAM-1 on the endo layer(stop rolling)
In adhesion, LFA-1 on leukocytes interact w/ what receptor on endothelial cell?
ICAM-1
In adhesion, VLA-4 on the leukocyte interact w/ which receptor on the endothelial cell?
V-CAM-1
During diapedesis, which kind if integrin help WBC to transmigrate?
PECAM-1
In diapedesis, what can secrete WBC to break-down the basement membrane and move through the endothelial layer?
Collagenases enzymes
Neutrophils
Hallmark of acute inflammation
Granule contains digestive enzymes (eg.: lysozymes)
Release inflammatory mediators
Eosinophils/basophils
Granules filled w/ inflammatory mediators
Useful against parasites
-part of immune reactions mediated by IgE
Life-threatening if triggered inappropriately (eg.: allergic reactions)
Monocytes/ macrophages
Hallmark of CHRONIC inflammation
Releases cytokines
Cause fever in generalized inflammatory responses
Highly concentrated in
- lymph nodes
- Spleen/other immune organs
Macrophage are activated by inflammatory mediators
How is called macrophages in the brain?
Microglia
How is called macrophages if the skin?
Langerhans cells
What are the 2 types of macrophage activation?
M1 = classical activation = IFN-y
M2 = alternative activation = IL-13 + IL-4
-activation of more powerful and specific fct
(Eg.: wound healing, phagocytosis)
Give 2 examples of M2 activation of macrophages fct
Wound healing
Phagocytosis
Which cells express TLR
Macrophage
Dentritic cells
Activation of TLR activates macrophage to do which fct?
Phagocytosis
Release of inflammatory mediators
What is an inflammasome?
Protein complex called NLRP3
It is a sensor prot + caspase-1 = enzyme
Recognises dead cell product (extacellular ATP, uric acid) and some microbe.
It increases the secretions of IL-1
IL-1 fct = mediators for leukocytes recruitment
Name 2 dead cell products
Extracellular ATP
Uric acid
What type of chemotaxis recruit neutrophils 1st in acute inflammation?
IL-8
In phagocytosis, the process of engulfment form a phagosome. What are found in the phagosome (2)?
ROS
Lysosomes
The leakage of those during phagocytosis is the source of tissue damage CHRONIC INFLAMMATION
Oxidative (resp) burst is trigger by what?
Phagocytosis
It increase 02 consumption and glycolysis
For extra prod of ROS
Large non-digestible particle can be engulfed and secreted to?
GIT
Leukocyte w/particle is excreted
MACROPHAGE w/ particule can DIVIDE
Daughter cell can resume normal fct
Mother cell is excreted
Which type of cell can divide before to be excreted in the GIT because of non-digestible particles engulfed?
Macrophages
