Term
| Chronic inflammation is the result of? |
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Definition
| continued inflammatory response in combination with an immune response against a persistent injurious agent. |
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Term
| define chronic inflammation |
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Definition
| prolonged duration (weeks, months, years) in which active inflammation, tissue injury and healing proceed simultaneously |
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Term
| list the three characteristics of chronic inflammation |
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Definition
- infiltration with mononuclear cells (macrophages, lymphocytes and plasma cells)
- tissue destruction, largely directed by inflammatory cells
- repair, involving new vessel proliferation (angiogenesis) as well as proliferation of fibroblasts and accumulation of ECM (fibrosis) |
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Term
| list the four precursers that chronic inflammation may arise from. |
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Definition
- acute inflammation
- an antigen
- persistent injury
- autoimmune disease |
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Term
| the factor which differentiates simple acute inflammation from chronic inflammation |
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Definition
| persistence of antigen, or injurious stimulus |
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Term
| Ultimate goal of chronic inflammation, and what does it depend on? |
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Definition
| to control and eventually eliminate the causal agent, the success of which depends on the extent of the immunologic response. |
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Term
| granulomatous inflammation is a distintive pattern of what which is characterized by what? |
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Definition
its a distinctive pattern of chronic inflammation.
it is characterized by aggregates of activated macrophages that assume a squamous cell-like (epitheloid) appearance surrounded by a collar of lymphocytes that secrete cytokines. With time, a rim of fibroblasts and connective tissue develops. There may be a central zone of necrosis. |
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Term
| the epitheloid appearance of aggregates of activated macrophages (a characteristic of granulomatous inflammation) is caused how? |
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Definition
| the presence of extensive Rough Endoplasmic Reticulum leads to enzyme secretion and decreased phagocytosis. (double check) |
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Term
| When does granulomatous inflammation develop? |
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Definition
when macrophages phagocytose the causal agent, but it survives inside them.
An active T-cell mediated immune response must occur and lead to production of lymphokines that cause macrophages to remain in the area, forming granulomas |
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Term
| list the steps of granulomatous inflammation starting with it being initially microscopic, to scar formation. |
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Definition
- initially microscopic
- enlarges
- surrounding functional tissue lost by necrosis (in case of infection by microorganisms, there is a central area of caseous necrosis [tissue maintains a cheese like appearance])
-scar formation |
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Term
true or false
adjacent granulomas are not able to fuse into larger masses. |
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Definition
false
they can fuse into larger masses. |
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Term
| when do foreign body granulomas develop? |
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Definition
when inert and non-antigenic foreign material enters a tissue and is too large to be phagocytosed by a single macrophage.
leads to numerous macrophages accumulated around and remove it by non-immune phagocytosis. |
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Term
| foreign body granulomas are more significant clinically or forensically? |
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Definition
| forensically. they are rarely clinically significant. |
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Term
| non-granulamatous chronic inflammation is characterized by? |
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Definition
| presence of sensitized lymphocytes, plasma cells, and macrophages scattered throughout the affected tissue, along with areas of necrosis and fibrosis. |
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Term
| list and describe the 5 common causes of non-granulamatous chronic inflammation. |
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Definition
CHRONIC VIRAL INFECTION
- B-cell and T-cell cytotoxic response leads to necrosis of affected cells
OTHER CHRONIC INFECTIONS
- ineffective T-cell response, large numbers of "foamy" macrophages accumulate diffusely without forming granulomas.
- low direct pathogenicity
- DTH response
CHRONIC AUTOIMMUNE DISEASES
- responsible antigens are constantly renewed because reaction is directed against self, leading to perpetuating immune reaction
ALLERGIC CONDITIONS AND PARASITIC INFECTIONS
- large numbers of eosinophils (white blood cells) and mononuclear cells accumulate in tissues affected by repeated or chronic acute hypersensitivity reactions (rapid death of cells in the local region surrounding an infection)
CHRONIC TOXIC DISEASES
- necrosis and fibrosis of tissue due to continued damage |
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Term
| how does chronic suppurative inflammation appear? |
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Definition
| appears as an area of necrosis and pus formation as well as infiltration with mononuclear cells and fibrosis (may become a prominent feature) |
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Term
| what surgical procedure is important for promoting healing in areas affected by chronic suppurative inflammation? |
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Definition
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Term
osteomyelitis is an example of which form of inflammation?
what does it refer to and describe hematogenous and secondary osteomyelitis |
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Definition
is a form of chronic suppurative inflammation
refers to inflammation fo the bone and marrow vacuity, where the lesions are caused by infection agents .
2 types:
HEMATOGENOUS OSTEOMYELITIS
- caused if bacteria carried by blood stream (if in kids, often seeded in epiphyseal cartilage (each end of long bone)
SECONDARY OSTEOMYELITIS
- develops as an extension from a wound or adjacent site infection |
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Term
| signs and symptoms of local and systemic chronic suppurative inflammation. |
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Definition
LOCAL
- bone inflammation
- pain
-swelling
-redness
SYSTEMIC
- fever
- malaise
- leukocytosis
- mild to moderate anemia |
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Term
| what is acute osteomyelitis characterized by? |
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Definition
- intense, neutrophilic inflammatory infiltrate at the site of bacterial invasion
- children: seeding in metaphysic of long bones
-adults: seeding in vertebral bodies |
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Term
| why does necrosis of affected bone (in acute osteomyelitis) occur rapidly? |
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Definition
- compression of vascular spaces by increased phosphorous in the marrow cavity
- increased concentration of enzymes and their mediators released during the acute reaction |
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Term
| describe the steps the occur in acute osteomyelitis if the infection spread to periostenum. |
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Definition
- if infection spreads to periostenum (membrane covering surface of bone)
-> subperiosteal abscess
-> detachment of periostenum
-> interruption of blood supply
-> further ischemic injury |
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Term
| chronic osteomyelitis is characterized by? |
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Definition
- osteoclast (removes bone tissue) activation
- fibroblast ( wound healing) proliferation
- new bone formation |
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Term
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Definition
residual fragments of necrotic bone reabsorbed (into bloodstream) from osteoclast activity
aka:
a piece of dead bone that has become separated during the process of necrosis from normal/sound bone. |
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Term
| why is chronic osteomyelitis difficult to treat? describe two complications |
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Definition
because it disrupts the blood supply which makes it difficult for systemic antibiotics to enter the site.
2 complications:
- development of draining tracts which lead to debris at skin surface
- possibility of pathologic fractures because of weakened bone which could lead to deformation. |
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Term
true or false
acute inflammation may lead to the deposition of an insoluble fibrillary protein in the interstitial tissue. |
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Definition
false
chronic inflammation may lead to deposition of an insoluble fibrillary protein in the interstitial tissue. |
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Term
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Definition
| group of diseases characterized by the deposition of similar appearing, insoluble protein (amyloid) in the interstitium of tissues |
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Term
| define systemic amyloidosis and describe the two types. |
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Definition
systemic: several organ system
two types:
PRIMARY AMYLOIDOSIS
- most ocmmon form, and is of AL type
- associated with multiple myeloma (malignant neoplasm of plasma cells) where only light chain subunits of Ig are secreted
SECONDARY (REACTIVE) AMYLOIDOSIS
- amyloid deposition which occur widely in the body, often in association with chronic inflammation diseases. |
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Term
| Give definition of and give three examples of localized amyloidosis. |
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Definition
localized: within a single tissue/organ
3 examples:
- amyloid plaques in the brain and alzheimer disease
- endocrine tumours (peptides Hs serve as precursors)
- local plasma cell tumours |
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Term
| describe familial amyloidosis |
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Definition
| rare, inherited disorders in which amyloid is deposited locally in organs such as heart, kidney or nervous tissue. |
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Term
| define amyloid, and describe the three most common types |
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Definition
amyloid: consists of characteristic beta pleated structure with underlying chemical structure, depending on the precursor protein.
3 most common:
SERUM AMYLOID ASSOCIATED (AA) NON-IMMUNOGLOBULIN
- protein, produced by liver during inflammatory process
IMMUNOGLOBULIN LIGHT CHAINS (AL)
- produced by some plasma cell or B cell tumours
AMYLOID AB
- characterizes the cerebral plaque lesions of Alzheimer disease |
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Term
| what is the significance of deposition? |
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Definition
| in sufficient quantities, it can cause the tissue to become enlarged and firm, leading to decreased nutrient diffusion and affect tissue function. |
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Term
| Healing leads to loss of parenchymal (functional parts of an organ) cells, which results in? |
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Definition
| division of adjacent cells to replace them |
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Term
| extent of regeneration during healing depends on |
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Definition
-ability of that cell type to divide
- number of dividing cells
- whether or not there is a surviving connective tissue "framework" to allow the normal tissue structure |
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Term
| describe the regenerative capacity of labile cells (cells that constantly divide by entering and remaining in the cell cycle) give example. |
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Definition
- normally divide actively throughout life
- short intermitotic (resting) phase
- injury is rapidly followed by regeneration from the basal germinative layers/stem cells, provided that sufficient number of labile cells have survived the injury
example:
- epithelial cells of skin and mucosal surfaces, hematopoietic (formation of blood cellular components) cells of bone marrow |
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Term
| describe the regenerative capacity of stable cells (cells that multiply only when needed). give example. |
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Definition
- long lived, slow rate of division
- reversibly post-mitotic, remaining in the intermitotic phase for years
- can regenerate after necrosis, provided that some cells have survived and there is connective tissue framework for support
examples:
- parenchymal cells of solid organs, fibroblasts (plays a critical role in wound healing), endothelial cells |
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Term
| Describe the regenerative capacity of permanent cells. give an example |
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Definition
- cannon divided after fetal life
- injury can only be healed by scarring. extensive injury will lead to functional deficit
example:
- nervous tissue, cardiac muscle |
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Term
| Scarring, is an area of dense ________, which is the result of healing by _________, that occurs when (3 things). |
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Definition
Scarring, is an area of dense COLLAGEN, the result of healing by FIBROSIS that occurs when:
- regeneration is not possible either because the injured cells are permanent or sufficiently widespread necrosis affected the tissue
- acute inflammatory process is not resolved
- there is ongoing tissue necrosis in chronic inflammation |
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Term
| briefly list the 6 processes that repair scarring (That occur somewhat concurrently) |
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Definition
-debridement
- granulation tissue formation
- angiogenesis
- collagenization
- maturation
- contraction |
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Term
| Describe debridement (a process of repair by scarring) |
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Definition
Removal of debris from area
- neutrophils release lysosomal enzymes to liquefy the debris
- debris removed by macrophages and lymphatics |
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Term
| Describe granulation tissue formation (a process of repair through scarring) |
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Definition
Filling of the injured area until more mature scar tissue can form.
- highly vascular immature connective tissue
- consists of proliferating fibroblasts, newly formed capillaries, and some inflammatory cells |
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Term
describe angiogenesis (a process of repair through scarring) and list it's importance and 4steps.
how do newly formed vessels lead to edemas (abnormal accumulation of fluid in the interstitium, which are locations beneath the skin)? |
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Definition
Pre existing vessels send out capillary sprouts to produce new vessels.
- it is important in wound healing, development of collateral circulation, and enlargement of tumours
1. proteolytic degradation of the parent vessel BM, allowing formation of a new capillary sprout
2. migration of endothelial cells from original capillary toward angiogenic stimulus.
3. proliferation of endothelial cells behind leading edge
4. maturation of endothelial cells with inhibition of growth, and organization into capillary tubes
- newly formed vessels are leaky which lead to increased transcytosis (process by which various macromolecules are transported across the interior of a cell), which contributes to edemas at healing wounds. |
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Term
describe collagenization (a repair process by scarring).
describe collagen and what its synthesized by. |
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Definition
a process by which collagen is laid down in the area
- collagen is an insoluble fibrillary protein, which gives much of the tensile strength to the scar tissue. it is synthesized by fibroblasts. |
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Term
| describe maturation (remodelling) [the process of repair by scaring] |
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Definition
process by which granulation tissue is gradually replaced by mature connective tissue
- increased collagen concentration leads to increased collagen cross linking and thus decreased vasculature |
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Term
| what is a contraction (a process of repair in scarring) caused by? |
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Definition
| its due to actomyosin filaments in certain fibroblasts |
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Term
| list and describe the seven types of skin injuries |
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Definition
ABRASION
-scrape tissues; epidermal cells are removed, basal layer not affected, regeneration occurs from below
LACERATION
- result of tearing of tissues; both epidermis and dermis affected
INCISION
- cutting of tissues; both epidermis and dermis affected
INCISION
- cutting of tissues; both epidermis and dermis affected; little loss of basal cells
CONTUSION
- bruising of tissues; blood vessel damage and hemorrhage
AVULSION
- tearing away of a part due to severe trauma
CRUSH INJURIES, BURNS, LARGE LACERATIONS
- extensive loss of epidermis
PUNCTURE WOUND
- stabbing of tissues; deep injury |
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Term
| describe healing by first intention |
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Definition
- important that wound edges are brought together
- quick healing process, minimal scarring.
process:
- vessel injury leads to hemorrhage
- tissue injury liberates thromboplastin (a plasma protein aiding blood coagulation) , which initiates clotting and scab formation
- the inflammatory response is initiated by mediators released from the damaged tissue
- cells of the basal epidermis begin to migrate (due to loss of contact inhibition), "flowing" under scab toward cut margins
- debridement- removal of tissue debris by phagocytes(neutrophils then macrophages)
- new capillaries form
- fibroblasts proliferate and produce collagen
- maturation of collagen gives strength to the wound
- contraction and remodelling of scar
[image] |
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Term
| describe healing by second intention, and how it differs from healing by first intention. |
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Definition
occurs when cell/tissue loss is more extensive, as in infarction (tissue death (necrosis) caused by an obstruction of the tissue's blood supply), inflammatory ulceration, abscess formation, or even just large wounds
differs from healing by first intention by:
- being slower
- large tissue defects which leads to greater volume of necrotic debris, exudate and fibrin that must be removed. this leads to more intense inflammatory rxn with greater potential for secondary injury
- much larger amounts of granulation tissue which leads to increased mass of scar tissue
- wound contraction is 5-10% due to presence of myofibroblasts (similar to smooth muscle cells) |
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Term
| list 5 possible complications with healing by second intention |
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Definition
- infection which leads to prolonged inflammation and increased local tissue injury
- type and volume of tissue injured which leads to labile vs. permanent cells
- location of injury -> if between spaces, leads to exudation ( fluid that filters from the circulatory system into lesions or areas of inflammation)
- aberrations of cell growth and ECM production leads to excessive collagen (-> keloid (3D looking scar)), or granulation tissue (-> proud flesh ( perfused, fibrous connective tissue that replaces a fibrin clot in healing wounds))
- chronic inflammatory disease (rheumatoid arthritis, cirrhosis, pulmonary fibrosis) |
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Term
| what are the 9 factors that influence the extent and effectiveness of wound healing? |
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Definition
-mechanical distortion
-nutrition: vit C, zinc and protein deficiencies->defective collagen synth
-drugs: corticosteroids
-foreign material
-blood supply: poor perfusion
-age
-size and shape of wound
-nature of injured tissue
-degree of immobilization |
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Term
| pathways of reparative response after actue injury |
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Definition
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