Mesa - Tissue repair Flashcards
____ is the growth of cells to replace lost tissues
regeneration
____ is a reparative tissue response to a wound, inflammation, or necrosis and often leads to fibrosis
healing
______ follows healing and requires a CT scaffold and occurs in proportion to the damage of the ECM
fibrosis
______ is one of the key concepts in neoplasia and can gain specialization and lose ____
differentiation; versatility
what are the cell types?
- labile: continuosly dividing; marrow; GI
- quiscent: stable; liver, kidney
- nondividing: permanent; neuron, striated muscle
what are the two mechanisms of stem cells
- obligatory assymetric replication: with each stem cell division, one of the daughter cells retains its self renewing capacity while the other enters a differentiation pathway
- stochastic differentiation: stem cell pop maintained by the balance bet stem cell divisions that generate either two self renewing stem cells or two cells that will differentiate
what are the different types of growth factors
- epidermal
- transforming
- hepatocyte
- vascular endothelial
- platelet derived
- fibroblast
- cytokines
what are the cells players and and targets?
- lymphocytes
- macrophages
- platelets
- endothelial cells
- fibroblasts
- keratinocytes
- mesenchymal cells
- smooth muscle cells
____ GF is made in platelets and macrophages. It is present in saliva, milk, urine, and plasma and acts on ____ to migrate, divide. Also acts on _____ to produce granulation tissue
Epidermal; keratinocytes; fibroblasts
_____GF is made in mesenchymal cells. Causes proliferation of _____, endothelium and hepatocytes. Effect on cell motility
Hepatocyte; epithelium
____ GF is made in mesenchymal cells as well and is triggered by ____. Increases vascular permeabilityy. Mitogenic for endothelial cells and is a key substance in promoting ______ tissue
Vascular endothelial; hypoxia; granulation
_____ derived GF is made in platelets as well as other cell types. Chemotactic for many cells. Mitogen for ____. Induces angiogenesis and is another key player in ______ tissue
platelet; fibroblasts; granulation
____ GF is made in many cell. IT is chemotactic and mitogenic for ____ and _____. Induces re-epithelialization and angiogenesis. important in cardiac/skeletal muscle
fibroblast; keratinocytes; fibroblasts
T(transforming) GF-beta is in many cells including macrophages and stimulates migration/proliferation of _____. Increases collagen synthesis and inhibits ____ cells. helps limit and terminate inflammatory responses
fibroblasts; epithelial
____GF is made in fibroblasts and is stimulated by migration, proliferation and ______
keratinocyte; differentiation
_____GF stimulates sulfated proteoglycans, collagen, keratinocyte migration, fibroblast proliferation, and acts similar to GH.
I (insulin)
_____ activates macrophages and is a key influence on other cytokines.
TNF (tumor necrosis factor)
_____ have many functions such as chemotaxis, angiogenesis, and regulation of other cytokines.
interleukins
_____ also activates macrophages but inhibit fibroblasts and also regulates other cytokines
interferons
____ signaling has to do with the same cell. ____ signaling has to do with the next door neighbor and includes many GFs. ____ signaling is far away is and is delivered by blood, and steroid hormones
autocrine; paracrine; endocrine
What ar the functions of the ECM
- maintain cell differentiation
- scaffolding
- establish microenvironment
- storage of GFs
The ECM is composed of 3 groups of macromolecules:
- fibrous structural proteins
- adhesive glycoproteins
- proteoglycans/hyaluronan
what makes up the fibrous structural proteins of the ECM
- collagen
- elastin
- fibrillin
what makes up the adhesive glycoprotein
- immunoglobulins
- cadherins
- integrins
- selectins
what makes up the proteoglycans/hyaluronan
- heparan sulfate
- chondroitin/dermatan sulfate
- keratan sulfate
Collagen I is main component of _____. Collagen II is main component of ______. Collagen III is main component of _____ and collagen VI is main component of the _____ membrane
bone; cartilage; reticular fibers; basement
what is the process of healing
proliferation and migration of CT–> angiogenesis–> collagen or other ECM protein synthesis –> tissue remodeling –> wound contraction –> increase in wound strength
neovascularization (angiogenesis) is from ____ precursor cells and pre existing vessels and is stimulated by GFs especially _____.
endothelial; VEGF
there is overlap between inflammation and _____ tissue
granulation
What are the two types of wound healing
- primary intention
2. secondary intention
describe primary intention
- edges are lined up
- minimizes scarring
- wound closure performed with stiches or adhesive tape
describe secondary intention
- edges are not lined up
- wound is allowed to granulate
- healing is slow due to presence of drainage from infection
- More granulation, epithelialization and fibrosis
what are local wound retarding factors
- decrease blood supply
- denervation
- local infection
- Foreign body
- hematoma
- mechanical stress
- necrotic tissue
what are systemic retarding wound factors
- decrease blood supply
- age
- anemia
- malignancy
- obesity
- infection
- organ failure
