Class #4: Inflammation and Tissue Repair Flashcards
_____________ is a non-specific immune reaction that occurs in response to any kind of bodily injury. It is a response that is identical regardless of the injurious agent
Inflammation
______________ is a protective response intended to eliminate the initial cause of cell injury, remove the damaged tissue, and generate new tissue.
Inflammation
Inflammation works by 1), 2), or otherwise 3) the harmful agent.
diluting, destroying, neutralizing
Causes of ______________
Immune response to pathogenic microorganisms
Trauma (sprains/ligament, strain/muscle)
Surgery
Caustics (burning/corrosives), chemicals (poisons)
Temperature extremes (burns)
Ischemic tissue damage
Inflammation
Identify the Classic/Cardinal Signs of Inflammation
S- H- A- R- P-
Swelling Heat Altered Function Redness Pain
The earliest (almost immediate) reaction of local tissue and blood vessels to injury
Acute inflammation
T/F: Acute inflammation typically lasts several weeks to a month
False: Is relatively short in duration, lasting from a few minutes to several days
Acute inflammation is characterized by the exudation of fluid and plasma components and emigration of leukocytes, predominately _______________, into the extravascular tissue
Neutrophils
Name some potential stimuli for acute inflammation
Infection, immune response, trauma, physical or chemical agents, and tissue necrosis from any cause.
When does acute inflammation become chronic?
When healing begins to occur at the same time as active inflammation.
Immediate vascular changes, vasodilation, and increased capillary permeability are part of __________
Acute inflammatory response (vascular)
Influx of white blood cells, e.g. neutrophils, monocytes and macrophages are part of ____________
Acute inflammatory response (cellular)
Word that describes things related to the physical aspects of blood circulation
Hemodynamic
T/F: The immediate vascular response to acute inflammation is a rapid vasodilation of the arterioles, and venules that supply the area with a resultant increase in capillary blood flow, causing heat and redness.
False: This comes after a momentary constriction of small blood vessels in the area
Accumulation of extrudates in the tissue spaces during acute inflammation produces 1), 2), and 3) of the affected part.
swelling, pain, and impaired function
As extrudates move out of the vessels during acute inflammation , 1) and 2) occur, which aids in preventing the spread of infectious microorganisms.
stagnation of flow and clotting of blood.
Vascular changes that may occur with inflammation include:
An 1) response occurs with minor injury
An 2) response occurs with more serious injury and
continues for several days and damages vessels in the area
A 3) response involves an increase in capillary
permeability that occurs for 4-24 hours after injury (e.g. sunburn)
1) immediate transient
2) immediate sustained
3) delayed hemodynamic
Cellular Response in Acute Inflammation is marked by movement of phagocytic leukocytes (aka_______________________) into the area of injury
White blood cells
Two types of leukocytes participate in the acute inflammatory response:
1) _____________ (neutrophils, eosinophils and basophils)
2) _____________ (the largest of the white blood cells)
1) Granulocytes
2) Monocytes
The sequence of events in the cellular response to inflammation includes:
They can only do this due to increased ______ and _______
- Margination
- Pavementing
- Trans-migration
vasodilation and capillary permeability
Margination and adhesion of leukocytes to the endothelial lining: occurs in early stages of inflammation in which WBCs tend to occupy the periphery (______________)
Pavementing
_____________ movement of the WBC out of the capillary into the interstitial space.
Transmigration
Chemically stimulated movement of phagocytes to the site of inflammation:
Chemotaxis
The process of phagocytic cells (i.e. neutrophils, monocytes, tissue macrophages) engulfing and destroying bacteria
Phagocytosis
Phagocytosis involves three
distinct stages:
- Recognition and
adherence - Engulfment
- Intracellular killing
Although inflammation is precipitated by infection and injury, its signs and symptoms are produced by _________________
chemical mediators
Some chemical mediators have ________ and __________ properties (e.g. histamine, prostaglandins, and leukotrienes)
vasoactive and smooth-muscle constricting
Some chemical mediators act as chemotactic factors such as __________ liberated from leukocytes and complement fragments. These factors when released into the extracellular environment can damage the surrounding tissue.
cytokines
___________ may develop as the result of a recurrent or progressive acute inflammatory response or from low grade responses that failed to evoke an acute response.
Chronic Inflammation
Chronic Inflammation is characterized by infiltration of ____________ and _____________, and by proliferation of fibroblasts (vs. acute: influx of neutrophils, exudate formation)
macrophages and lymphocytes
Granulomatous formation leads to ________________
formation, a small lesion, which has a mass of macrophages surrounded by lymphocytes.
granuloma
Type of inflammation associated with foreign bodies (splinters, sutures, silica, asbestos)
Granulomatous formation
In non-specific chronic inflammation, there is a diffuse accumulation of macrophages and lymphocytes at the site of injury. Fibroblast proliferation occurs with subsequent scar formation that replaces
the normal connective tissue or the ___________(e.g. in the bowel this can cause narrowing of the bowel lumen).
parenchyma
Watery fluids low in protein content, results from
plasma entering the inflammatory
site (e.g. blister)
Serous
Occurs when there is severe tissue injury that causes damage to blood vessels, or when there is significant leakage of red blood cells from capillaries
Hemorrhagic
develops on mucous membrane surfaces; composed of necrotic cells enmeshed in fibro-purulent exudates (e.g. tonsillitis)
Membranous or pseudomembranous
contain pus: degraded WBCs,
proteins, tissue debris (necrotic
tissue), bacteria, edema; found in abscess or as pockets of pus
Purulent
Usually from more severe injuries and from greater vascular permeability that allows larger molecules such as fibrinogens through the vascular barrier. Characteristic of inflammation in body cavities such as the pericardium and pleura. Resolves by scar formation between the parietal and visceral surfaces, with fibrous strands within the space.
Fibrinous
A localized area of inflammation containing purulent exudates
Abcess
A site of inflammation where an epithelial surface (e.g. skin or gastrointestinal epithelium) has become necrotic and eroded.
Ulceration
In some cases, inflammatory mediators are released into the circulation resulting in prominent ________. These include:
Acute phase response
Alteration in the white blood cell count
Fever
Lymphadenitis (inflammation of the lymph nodes)
Sepsis (infection in the blood) and septic shock
systemic manifestations
Tissue repair that results when there is minimal tissue damage and cell necrosis (e.g. paper cut, small splinter)
Resolution
Tissue repair that results in damaged tissue in which the cells are capable of mitosis
Regeneration
Tissue repair that results when there is extensive tissue damage or the cells are incapable of mitosis. Injured cells are replaced by connective tissue which leaves a permanent scar, also known as fibrous tissue repair.
Replacement
_______________ tissue: contains the functional cells of an organ or body part. Body cells are divided into three types according to their ability to undergo
regeneration: labile, stable, or permanent cells.
Parenchymal
_______________ tissue: consists of the supporting connective tissues, blood vessels, extracellular matrix, and nerve fibers.
Stromal tissue
There are three basic components of _____________:
- Fibrous structural proteins e.g. collagen and elastin fibers
- Water hydrated gels that permit resilience and lubrication e.g. proteoglycans and hyaluronic acid
- Adhesive glycoproteins that connect the matrix elements to one another and to cells e.g. fibronectin and laminin.
extracellular matrix (ECM)
ECM exists in two forms:
- Basement membrane: (BM) surrounds epithelial, endothelial, and smooth muscle cells
- Interstitial matrix: present in the space between cells in connective tissue, and between the epithelium and supporting cells of blood vessels
Regeneration is limited to tissues with cells that are able to undergo _________.
Mitosis
Type of tissue repair seen in mild to moderate injury.
Tissue Regeneration
Tissue ____________involves replacement of injured tissue with the cells of the same type, leaving little to no evidence of previous injury.
Regeneration
Cells that continue to divide and replicate throughout life, replacing cells that are continually being destroyed.
Labile cells
Cells that normally stop dividing when growth ceases. These cells are capable of undergoing regeneration when confronted with an appropriate stimulus and are capable of reconstituting the tissue of origin.
Stable cells
Cells that cannot undergo mitotic division. These cells do not normally regenerate. Once destroyed, they are replaced by fibrous scar tissue that lacks the functional characteristics of the destroyed tissue.
Permanent or Fixed Cells
This type of repair occurs with severe or persistent injury.
Replacement/Fibrous Tissue Repair
This type of repair takes place when there is damage to both parenchymal cells and extracellular matrix.
Replacement/Fibrous Tissue Repair
_____________ is a glistening red, moist, connective tissue. It contains newly formed capillaries, proliferating fibroblasts, and residual inflammatory cells.
Granulation tissue
The development of granulation tissue involves the growth of new capillaries (_____________), _______________, and involution to the formation of scar tissue.
Angiogenesis
Fibroblasts
________________ involves the generation and sprouting of new blood vessels from pre-existing blood vessels, present as minute red granules from the surface of wound (hence the name granulation tissue).
Angiogenesis
_______________involves the influx of activated fibroblasts:
Fibrogenesis
_________________ formation builds on the granulation tissue framework of new vessels and loose ECM.
Scar tissue
The process of ______________ occurs in two phases:
- Emigration and proliferation of fibroblasts into site of injury, and
- Deposition of extracellular matrix by these cells
scar tissue
Primary objective of ____________ is to fill the gap created by tissue destruction and to restore the
functional continuity of the injured part
wound healing
Also known as healing by first intention. A sutured surgical incision is an example of healing by primary or first intention. It occurs at a faster rate and there is no loss of tissue. Example: C-Section scar
Primary intention
Larger wounds (burns and surface wounds) have a greater loss of tissue and higher risk of infection. These heal via _______________.
It occurs at a slower rate.
There is loss of tissue.
Large amount of scar tissue formation
Secondary intention
Phase of wound healing that begins at the time of injury
It includes hemostasis (activated immediately by platelet activation and aggregation), and vascular and cellular phases of inflammation.
This phase can last from 3-4 days.
Inflammatory phase
Phase of wound healing that begins within 2-3 days of injury. It may last for 2-3 weeks. Primary focus is to build the new tissue to fill the wound space. This phase is characterized by: Angiogenesis Collagen synthesis Granulation tissue formation Epithelialisation Wound contracture
Proliferation phase
Phase of wound healing that begins approximately 3 weeks after injury.
It can continue for 6 months or longer depending upon extent of wound.
Collagen is remodeled and realigned along lines of tension.
Cells that are no longer needed are removed by apoptosis.
Maturation or Remodelling Phase
In this process “drying up” cells become dehydrated and die. Healing is better in a somewhat moist environment (e.g. with a “moisture retention” dressing) as it enhances epidermal cell migration and encourages epithelization.
Desiccation
Deterioration of tissue due to prolonged exposure to excessive moisture (e.g. due to urine and fecal incontinence)
Masceration
One type of abnormality in healing by scar tissue is “___________” (tumor-like masses caused by the excessive production of collagen). DO NOT FRICTION or DO SPECIFIC/DEEP MASSAGE
keloid formation