L6, L9, L12- Inflammation and Repair Flashcards
Inflammation occurs in order to remove (1) via changes in (2) and (3). This is important for setting up (4). The inflammatory reaction is considered apart of (innate/adaptive) immunity.
1- injurious agent
2- vascular
3- cell
4- the base for tissue healing and repair
5- innate (although helps prepare the adaptive immune response)
Some negative effects of inflammation include exacerbation of (1) causing (2). If inflammation fails, (3) may occur. Inappropriate inflammation reactions may also occur in response to (4) and (5).
1- tissue injury
2- pain
3- abscess / fail to clear infection => further complications
4- nonharmful environmental Ags, allergic disease
5- self-Ags, autoimmunity
list the 5 general steps of the inflammatory response
1) offending agent recognized
2) recruitment of leukocytes and plasma proteins (to site of offending agent)
3) leukocytes and proteins activated to eliminate offending agent
4) reaction is controlled and terminated
5) damaged tissue is repaired
define acute inflammation
- initial rapid response: develops w/in mins-hrs, lasts for hrs-days
- characterized by presence of exudate
- predominate leukocyte = neutrophils
define chronic inflammation
- develops slowly, lasts for longer duration than acute
- associated with more tissue destruction
- predominate leukocyte = lymphocytes and macrophages
list the cardinal signs of inflammation
- rubor (redness)
- calor (heat)
- dolor (pain)
- tumor (swelling)
- loss of function (function laesa)
list some causes of inflammation
- infections: bacterial, viral, fungal, parasitic
- trauma / physical agents
- chemical agents
- tissue necrosis (any cause)
- foreign body (ex. sutures)
- immune rxns
the key cell receptor for microbial recognition is _____ (include some defining characteristics)
- Toll-like receptors (TLRs)
- distinguish self and foreign
- when activated, production of certain molecules promote inflammatory reaction
Cells have sensors in the (1) to recognize various molecules, including (2), that are liberated / altered as a result of cell damage. They activate (3) to induce (4).
1- cytosol
2- ATP, uric acid, DNA, etc
3- inflammasome formation (multiprotein cytosolic complex)
4- CK production
leukocytes can recognize (1) or (2) surrounding microbes, after a process called (3), which results in release of CKs to initiate (4)
1- Abs (IgG)- recognizing its Fc tail
2- complement protein (C3b)
3- opsonization
4- inflammatory response
(1) can recognize microbial sugars / proteins to promote (2) and (3). Examples include (4).
1- circulating proteins
2- ingestion
3- complement activation
4- mannose binding lectin, collectins
events of acute inflammation include (1) followed by (2)
1- vascular changes
2- cellular events
list the two parts of vascular changes seen in acute inflammation- includes their purpose
1) changes in vascular caliper (diameter/dimensions) and blood flow: vasodilation and turbulent flow
2) inc vascular permeability
- purpose is to maximize movement of plasma proteins and leukocytes out of circulation and into site of infection / injury
the escape of fluids from vasculature to interstitial tissue is called (1) and the fluid is referred to as (2)
1- exudation
2- exudate
Immediately after an injury or infection, associated vasculature will undergo (1) briefly before (2) occurs due to various mediators, but mostly due to (3). This results in (4) to give rise to the following cardinal signs of inflammation: (5).
1- neurogenic vasoconstriction 2- vasodilation 3- histamine 4- inc blood flow (turbulent flow) 5- heat (calor) + redness (rubor) = erythema
Following vasodilation in area of injury/infection, vasculature will undergo (1) leading to (2) and (3). (4) and (5) of the blood in the microvasculature is evident to cause (6).
1- inc permeability 2- loss of fluid 3- inc vessel diameter 4- slower blood flow (turbulent flow) 5- inc viscosity 6- stasis
what is the purpose of stasis
- blood leukocytes accumulate along vascular endothelium
- easier for leukocytes to adhere to endothelium and then migrate through vascular wall –> interstitial tissue
define exudate
- the fluid present in interstium at site inflammation
- high protein content
- some WBCs and RBCs present
describe the 4 mechanism that can increase vascular permeability
- gaps due to endothelial contraction: venules, most common, via vasoactive mediators, fast and short-lived (mins)
- endothelial injury: arter./capil./venul., toxins/burns/chemicals, fast and long-lived (hrs-days)
- leukocyte endothelial injury: venules (pulmonary capillaries), late and long lived (hrs)
- increased transcytosis: venules, vascular endothelium derived growth factor
what is the response of lymphatic vessels in inflammatory process
- dilatation (inc diameter)
- lymphangitis (inflammation of vessels: dilation, inc permeability)
- lymphadenitis (enlargement of lymph nodes)
list the two parts of cellular events seen in acute inflammation
1) leukocyte recruitment
2) leukocyte activation
list the general steps of leukocyte recruitment in acute inflammatory response [include which leukocytes]
[mainly neutrophils]
1) margination, rolling, adhesion to endothelium
2) migration across endothelium + vessel wall (diapedesis)
3) migration in tissue to chemotactic stimulus (chemotaxis)
margination of leukocytes occurs due to (1) in early inflammatory response and since there is a decrease in (2), WBCs assume a (3) position
1- slowed blood flow (turbulent flow) / stasis
2- wall shear stress
3- peripheral position along the endothelium
define rolling of leukocytes
- transient adhesion of leukocytes to endothelium
- repeated process of binding and detaching => rolling along vessel wall
the interactions of the following are responsible for rolling of leukocytes
(selectins- expression regulated by CKs)
- L-selectins, leukocytes
- E-selectins, endothelum
- P-selectins, platelet + endothlium
The weak rolling interactions of leukocytes and endothelium mediated by (1) help slow leukocytes down enough to allow them to adhere via (2) present on leukocytes and (3) and (4) present on endothelial cells.
1- selectins
2- integrins
3- VCAM-1 (vascular cell adhesion molecule)
4- ICAM-1 (intercellular adhesion molecule)
Migration of leukocytes across the endothelium and vessel wall is called (1) and usually occurs in (2) type vessels. (3) is an important adhesion molecule involved. Leukocytes pierce the basement membrane by (4) to enter extravascular tissue.
1- transmigration, diapedesis
2- postcapillary venules
3- PECAM-1 (platelet endothelial cell adhesion molecule)
4- secreting collagenases
list the molecules responsible for chemotaxis
- CKs- IL-8
- C5a
- LT-B4
- bacterial products
order the following by which they peak in an acute inflammatory response: edema, monocytes/macrophages, neutrophils
- edema (quickly): recruit leukocytes
- neutrophils (~1 day): destroy offending agent
- monocytes/macrophages (~2 days): repair damaged tissue
list the three results of leukocyte activation once they recognize microbes or dead cells
- phagocytosis
- intracellular killing of engulfed pathogen
- production of mediators to amplify inflammatory reaction
list the steps of phagocytosis
1- recognition + attachment of particle to be ingested by leukocyte
2- engulfment
3- killing/degradation of ingested material (via phagosomal-lysosomal fusion)
the key opsonizers in the immune system are….
-IgG
-C3b (complement)
-collectins
(they function to enhance leukocyte attachment to microbial surfaces)
intracellular killing within phagocytes occurs via….
- O2 dependent killing (ROS)
- O2 non-dependent enzymatic killing (+ RNS)
list methods where leukocytes can cause tissue damage
(leakage of lysosomal contents into extracellular space)
- Phagosome leakage: regurgitation during feeding
- attempting to phagocytose large molecules (futile phagocytosis)
- engulfment of cytotoxic material => phagocyte disintegration