Ch3 - Inflammation And Tissue Repair Flashcards
Inflammation is a non-specific response of body to local tissue injury. Part of the _________ of defense.
2nd line defense
Functions of inflammation?
- Increase blood flow to site (vascular response)
- Increase healing cells at site (cellular response)
- Prepare for tissue repair
Lines of defense:
▫️first:
▫️second:
▫️third:
1st: skin and mucous membranes
2nd: Inflammatory
3rd : immune response
Causes of inflammation?
▫️infection - microbial agent
▫️physical agents - trauma, electrical, temperature
▫️radiation - ionizing, nonionizing, UV
▫️chemicals - acid, alkali, toxins
🔹drugs, lead, ethanol, mercury
▫️nutritional - excesses or deficiencies
▫️ischemia/infarction- auto, allo, allergy
▫️Genetic and metabolic disorders
Advantages of inflammation?
▫️serves to isolate and localize injured area, protecting normal tissue
▫️can neutralize and inactivate toxic substances
▫️destroys and limits growth of microorganism
▫️prepares the area for wound healing and repair by cleaning debris
Disadvantages of inflammation:
▫️Infection: microorganisms ca more easily penetrate oedematous tissues
▫️deep ulcers: result of severe or prolonged inflammation
▫️scar tissue: due to excessive tissue damage
▫️local complications: depend on site of inflammation but may include obstruction, loss of sensation, and decreased cell function.
▫️Pain
Chemical mediators?
🔹Cell-derived
🔹plasma derived
Cell-derived?
🔺white blood cell
🔺platelets
🔺endothelial or damaged tissue cells
Plasma-derived:
🔺complement system
🔺kinin system
🔺clotting system
it’s primary role is to destroy and remove microorganisms to prevent infection through opsonization (making bacteria vulnerable to phagocytosis) and cell lysis (destruction)
*produced in the liver
Complement
promotes coagulation through a cascade of clotting factors
Clotting
Source of highly potent vasoactive inflammatory mediators. Amplifies the inflammatory response by triggering other inflammatory mediators.
Kinin
Vascular response?
▫️increased capillary membrane permeability
▫️vasodilation
▫️hyperaemia
Cellular response ?
▫️chemotaxis
▫️cellular adherence
▫️cellular migration
_______cells are housed in connective tissues of body and near all blood vessels - allows for immediate release of chemical mediators into blood stream
Mast cell
_________are released from WBC platelets and injured cells and signal to trigger, enhance or discontinue the inflammation response.
Cytokines
Cells Active in cellular response:
▫️leukocytes ▫️neutrophils ▫️macrophages ▫️erythrocytes ▫️platelets
Role of these cell is phagocytosis; removal of dead tissue
Leukocytes
A type of WBC; earliest phagocytize responders
Neutrophils
A type of WBC; Large, king-lived phagocytes associated with a prolonged (chronic) inflammatory response; monocytes are immature macrophages
Macrophages
It’s a type of cell that carry oxygen to tissues
Erythrocyte
It’s a type of cell that trap harmful substances; stop bleeding; form structural origin of repair
Platelets
Healing undergoes:
- scar tissue
- Regeneration (replacement by same type of cell)
- Resolution (damaged cells recover)
Local Manifestation of acute inflammation:
5 cardinal clinical signs
- Redness (erythema)
- Heat
- Incapacitation
- Pain
- Exudate and edema
Other possible systemic manifestations:
- Malaise Headache
- Fatigue
- Anorexia
- Mild fever - due to pyrogens from macrophages
- Increased circulating leukocytes and plasma proteins
Benefits of fever
▫️stimulates phagocytosis
▫️decreases rate of multiplication of pathogens
▫️prevents release of Fe & Z from liver which bacteria feed on
▫️increased tissue repair process
Treatment of inflammation:
▫️reduced blood flow
▫️ decrease swelling
▫️block the action of chemical mediators
▫️decrease pain
type of inflammation, usually rapid onset w/ minimal damage and rapid resolution. It is characterized by the formation of exudates/edema.
Acute
A collection of interstitial fluid formed in the inflamed area.
Edema
Function of exudates:
- Carry plasma proteins and leukocytes to injured area
- Neutralize the inflammation reaction
- Dilute toxins
Type of exudates - watery, with low protein; usually seen w/ burns or allergic reactions (mild inflammation)
Serous exudate
Type of exudate, blood vessels damage with leakage of RBCs from capillaries
Hemorrhagic exudate
Type of exudate, contains large amounts of fibrin increasing the risk of scar tissue build-up in the area
Fibrinous exudate
Type of exudate, contains pus (degraded WBC, proteins and tissue debris); caused by certain microorganisms. Indicates bacterial infection.
Purulent exudate
Type of exudate, firms on mucous membranes and contains lots of mucous, ex. Rhintis, bronchitis
Catarrhal
It’s an inflammation that may last for weeks, months or years.
Chronic inflammation
Chronic inflammation may be the result of:
▫️an acute inflammation when the cause is not completely eradicated because the body is either:
🔺unable to remove the inflammatory agent
🔺 unable to destroy the inflammatory agent
🔺has an inadequate defense system
◽️an insidious dev’t due to chronic irritation
▫️when it involves certain type of bacteria (TB)
In chronic inflammation, the major WBC moving to site?
Macrophages and lymphocytes
Proliferation of fibroblasts also occurs, w/c can lead to:
▫️scarring and deformity
What are the factors that inhibit repair?
- Old age
- Nutrition
- Immune depression
- Certain diseases (ex. Diabetes)
- Malignancy (ex. Leukaemia)
- Drugs
- Superimposed infection
Increase blood flow to site
Vascular response
Increase healing cells at site
Cellular response
Inflammatory mediators
Mast cells and cytokines
An inflammatory mediator released from WBC, platelets and injured cells and signal to trigger, enhance or discontinue the inflammation response
Cytokines
An inflammatory mediator housed in connective tissues of body and near all blood vessels - allows for immediate release of chemical mediators into blood stream.
Mast Cells
It’s a type of WBC that release bradykinin - produces histamine
Basophil
What cell is activated by chemotaxis?
chemokines
Local manifestation of acute inflammation
- Redness (erythema)
- Heat
- Incapacitation
- Pain
- Exudate and edema
Other possible systemic manifestations:
- Malaise Headache
- Fatigue
- Anorexia
- Mild fever
- Increased circulating leukocytes and plasma proteins
In chronic inflammation, _____ and ; _____ instead of neutrophils are the major WBC moving to site
▫️macrophages and lymphocytes
Inflammatory cell in acute inflammation?
▫️neutrophil and macrophages
Inflammatory cells in chronic inflammation?
Lymphocytes, plasma cells, macrophages, fibroblasts (for scarring)
The body organs and structures contain 2 functional types of tissues:
▫️parenchyma (functioning cells)
▫️stroma (supporting connective tissue)
The primary objective of healing process is to “fill the gap”
▫️restore the structural continuity of the injured part
Secondary objective of healing process is _______ of the injured part.
restore the functional continuity
Injured tissues heals by:
- Resolution (if tissue damage is minimal)
- Regeneration ofvparenchymal cells
- Replacement with connective tissue
Chemical mediators are involved with healing process:
▫️chemotaxis; fibroblast recruitment
▫️proliferation of cells
Ability to regenerate varies with cell type:
▫️labile Cells - skin and mucous membranes
▫️stable cells - undergo mitosis as necessary
▫️permanent cells - amitotic
A cell that form lining of stomach and esophagus and are continuously being replaced.
▫️Labile Cells
A bone cells divide only when necessary
▫️ Stable cells
Is a type of cell once injured from ischemia, cardic Cells cannot be replaced.
Permanent cells
Non-regenerated parenchymal Cells are replaced by a ________ (process also called fibrosis) when:
🔺extensive tissue damage occurred
🔺 cells are amitotic
▫️CT scar
Wound healing and closure occur by _______ or _______ intention depending on the extent of tissue damage.
▫️primary
▫️secondary intention
▫️ ________ intention - small wound e.g. sutured surgical incision or paper cut
▫️_________ intention - e.g. burns, large surface wounds - tissues have undergone greater loss of tissue and contamination
▫️primary intention
▫️secondary intention
Tissue healing phases:
- Inflammation
- Proliferation (repair, regeneration, replacement)
- Remodelling
Injury that heal by secondary intention undergo:
▫️wound contraction
chemotactic mediators, or ________, stimulate a cellular response:
▫️chemotaxis
▫️adherence
▫️migration
▫️phagocytosis
Chemokines
For chronic inflammation:
▫️macrophages
▫️lymphocytes
For acute inflammation
▫️PMNs
▫️Platelets
▫️Mast Cells
Cell derived chemical mediators:
▫️WBC
▫️Platelets
▫️endothelial or damage tissue cells
Plasma derived chemical mediators:
▫️complement system
▫️Kinin System
▫️clotting System
it’s a plasma derived cell whose primary role is to destroy and remove microorganisms to prevent infection through opsonization (making bacteria vulnerable to phagocytosis) or cell lysis (destruction)
Complement
Plasma derived cell that promotes coagulation through a cascade of clotting factors
Clotting
Is a plasma derived cell which is a good source of highly potent vasoactive inflammatory mediators. It amplifies the inflammatory response by triggering other inflammatory mediators
Kinin
What’s vascular response to these cell mediators?
▫️increased capillary membrane permeability
▫️vasodilation
▫️hyperaemia (excess blood in the body part)
Cells active in the cellular response:
▫️leukocyte (WBC) ▫️neutrophils ▫️macrophages ▫️erythrocytes ▫️platelets
Is a cell that trap harmful substances; stop bleeding; form structural origin of repair
Platelets
A type of WBC; earliest phagocytic responder
Neutrophils
In blood test, it is elevated during inflammation to promote coagulation
this is needed for scar formation
Fibrinogen
In blood test, is increased above 10,000/mm3
reference value: 5,000 - 10,000 blood cells/mm3
WBC count
Extra cellular fluid accumulation often in tissues because of increased vascular permeability
Exudate and edema
Other manifestation of acute inflammation:
▫️malaise headache
▫️fatigue
▫️anorexia
▫️mild fever - due to pyrogens from macrophages
▫️increased circulating leukocytes and plasma proteins
What are the benefits of fever?
▫️stimulates phagocytosis
▫️decrease rate of multiplication of Pathogens
▫️prevents release of Fe and Z from liver which bacteria feed on ( this happen w/ low fever only)
▫️increased tissue repair process
Treatment for inflammation
▫️reduce blood flow
▫️decrease swelling
▫️block the action of chemical mediators
▫️decrease pain
Functions of exudates:
▫️carry plasma proteins and leukocytes to injured area
▫️neutralize the inflammation reaction
▫️dilute toxins
Body organs and structures contain two functional types of tissues:
▫️parenchyma (functioning cells)
▫️stroma (supporting connective tissue)
Tissue healing phase, usually begins w/ 2 to 3 days of injury and may lasts as long as 3 wks
Fibroblast produce collagen
healing by 2ndary intention - more granulation tissue
Phase 2 - proliferative phase
Healing phase where scar tissue remodels by breaking down old collagen (collagenase) and synthesizing new collagen (by fibroblasts)
Injury that heal by secondary intention undergo wound contraction
Phase 3 - remodeling phase
complications of healing by scarring:
- Contractures / obstructions
- Adhesions ( connection of scar tissue between 2 separate tissues ex. Intestines)
- Ulceration
- Dehiscence (wound separation)
- Hypertrophic scar formation (keloids)
**dehiscence & ulceration can easily lead to infection
A type of mediator such as histamine, leukotrenes, and prostaglandins
Aspactive mediators
Also called chemokines. A type of mediators that stimulate cellular response
Chemotactic mediators
Two cells with active vasoactive mediators. Both WBC, causes hyperaemia (⬆️of blood to area)
Mast cell and basophil cell
