Healing and Repair Flashcards
what is a normal immune reaction targeting innocuous antigens
hypersensitivities
define hypersensitivity diseases
environment and food antigens can cause immediate and sometimes persistent release of inflammatory mediators
what is the main immunologic component of a Type 1 hypersensitivity
IgE
what are examples of a Type 1 hypersensitivity
anaphylaxis, Atopy
which hypersensitivity disease occurs when antibodies can be formed against antigens on the body’s own cells or tissues resulting in complement and cellular responses
Type 2
what is the main immunologic component of a Type 2 hypersensitivity
cytotoxic Antibodies
what are some examples of a Type 2 hypersensitivity
IMHA
Myasthenia gravis
Pemphigus foliaceus
which hypersensitivity disease occurs when there is excessive formation of antigen-antibody complexes can deposit in capillaries and activate complement and other factors
Type 3
what is the main immunologic component of Type 3 hypersensitivity
Antigen-Antibody Complex
what are some examples of a Type 3 hypersensitivity
glomerulonephritis
vasculitis
why are Type 3 hypersensitivity diseases dangerous
travel in blood
can cause necrosis by getting lodged/ jamming vessels
which hypersensitivity disease has cytotoxic T-lymphocytes hypersensitized to a host’s own cells resulting in cellular destruction
Type 4
what is the immunologic component of a Type 4 hypersensitivity
cell-mediated T-lymphocytes
what are some examples of a Type 4 hypersensitivity
Type 1 diabetes mellitus
rheumatoid arthritis
which hypersensitivity has allergen-specific IgE binding to mast cells
Type 1
which hypersensitivity has antigen-antibody complexes deposited in tissues
Type 3
which hypersensitivity has antibodies binding to cellular antigens
Type 2
which hypersensitivity has Th1 cells secrete cytokines that activate cytotoxic T-cells
Type 4
true or false
inflammation always precludes healing
false
inflammation doesn’t preclude healing
what are the overlapping components of acute inflammation and healing
neutrophils
fibrin deposition
cytokines and other factors
oxygen and nutrient delivery
what are the overlapping components of chronic inflammation and healing
macrophages
granulation tissue
cell repopulation
what are the 2 mechanisms in which tissue can heal
healing by regeneration
healing by repair
which healing process has dead cells that are replaced by an identical cell type and tissue homeostasis is restored or near-restored
healing by regeneration
which healing process has dead cells that must by replaced by another cell type (usually fibrous connective tissue)
healing by repair
what controls the type of healing that occurs
extent of injury
cell type involved
which healing process requires that the progenitor cells and underlying supportive tissue is still in place
healing by regeneration
which healing process occurs if there is a loss of the progenitor cells and underlying supportive tissue
healing by repair
what is often seen as the outcome of healing by repair
scars / scar tissue
which type of cell has a high regenerative capacity
labile cells
which type of cell has regenerative capacity when stimulated
stabile cells
which type of cell has little to no regenerative capacity
permanent cells
what are the characteristics of a labile cell
cells with high turnover
tissues are regenerative for the lifespan of the host
where can labile cells be found within the body
epithelium
GI tract
bone marrow
in parvo cases, what causes the severe leukopenia
consumption of immune cells
necrosis of labile cells
true or false:
stabile cells need to be stimulated in order to participate in regeneration
true
what organs contain stabile cells
liver
kidney
pancreas
adrenal
bone
tendon
nerve/ smooth muscle cells
if an animal has severe damage to a stabile cell organ, what is often the outcome if they survive
loss of progenitor cells and supporting structures will encourage healing by repair / fibrosis
what are the steps of bone repair
1) stabilized by hematoma
2) fibrous connective tissue
3) healing by regeneration of osteocytes
what type of cells have limited to no regenerative capacity
permanent cells
what tissues are made up of permanent cells
skeletal and cardiac muscle
central nervous system
what replaces the damage tissue at the end of healing by repair
scar tissue
what is often seen on cytology/histopathy in cases of healing by repair
nuclear hypertrophy and ‘rowing’
actual deposition of new muscle cells is non-existent
what is the hallmark of chronic inflammation
granulation tissue
what is the process of fibrosis
1) injury
2) fibrin exudate
3) granulation tissue
4) fibrosis
what is granulation tissue made up of
new blood vessels and fibroblasts
what process occurs when endothelial cells in adjacent blood vessels proliferate and grow towards the area of injury and mature into blood vessels
angiogenesis
what is the function of myofibroblasts at the site of an injury
secrete collagen for structural integrity
how is new granulation tissue deposited for structure
distinct criss-cross pattern
why is there a decreased presence in vascularity within granulation tissue as it becomes fibrous
collagen netting starts to choke out the vessels/ blood supply
what is the healing pattern of granulation tissue
from periphery to center
what is ‘proud flesh’
exuberant granulation tissue
- tumor-like proliferation of granulation tissue
how does exuberant granulation tissue form
constant stimulation associated with excessive movement, lack of soft tissue, infection and low blood supply
what process of healing can not occur with constant stimulation of granulation tissue
fibroblasts likely failing to go through apotosis meaning they keep creating new tissue
true or false:
CNS damage is repaired by fibroblasts
false
there are no fibroblasts in the CNS
what replaces neural tissue in cases of damage
reactive astrocytes and microglial cells
what is the product of reactive astrocytes and microglial cells in the CNS
glial scar
true or false:
all CNS tissue is still functional in the presence of a glial scar
false
scar prevents axonal and neuronal growth
what are the 6 steps in primary union healing
1) clot formation
2) inflammatory response
3) fibrin scaffolding
4) continuity of blood flow
5) epithelial regeneration
6) collagen formation
what is the purpose of having an inflammatory response due to primary union healing
resolution of exudate
phagocytes digest dead tissue and fluid is absorbed back into the blood stream and lymphatics
what is formed in relation to the fibrin acting as a scaffolding during primary union
granulation
how does the tissue ensure continuity of blood flow in primary union
endothelial proliferation mature to blood vessels that connect the margins of the wound
(neovascularization)
what are the steps to secondary union
1) Hemorrhage and coagulation
2) inflammatory response and phagocytosis of debris
3) large amount of fibrin deposition leading to granulation tissue
4) deficit begins to be filled by granulation tissue
5) granulation matures to fibrous connective tissue
what is used to ‘mature’ granulation tissue
fibrocytes, decreased vascular presence and collagen contraction
what are 5 situations that might delay healing and cause complications
1) strength of stimuli for cell division and proliferation
2) physiologic conditions
3) mobility of tissue
4) tissue type
5) immunodeficiencies
how do we support stimuli strength
ensure adequate perfusion of injury
debride dead tissue
test for underlying hormonal imbalances
exogenous administration of drugs
