Repair - Nichols Flashcards
What is the difference between regeneration and scarring?
Regeneration is repair with the growth of fully functional tissue to replace injured or dead tissue. It is rare. It requires an intact connective tissue scaffold or only superficial injury.
Scarring replaces dead tissue with fibrous tissue lacking the specialized function of the tissue it replaces.
What is an ulcer?
an excavation in the surface of an organ or tissue produced by sloughing of inflamed necrotic tissue. It is deeper than an erosion, which is superficial sloughing of mucosa.
What is the difference in the healing process of ulcers and erosions.
Erosions aren’t as deep as ulcers and heal by regeneration.
Ulcers are deeper and heal by scarring.
What is an adhesion?
an abnormal connection between any two things int he body.
What are adhesions predominantly composed of early on? Later?
fibrin. Later fibroblasts add collagen.
What is a fistula?
abnormal opening between two places in the body
What type of replication do stem cells undergo?
asymmetric replication: in every division, one daughter cell retains self-renewing capacity and the other enters a differentiation pathway to a mature cell.
What is special about embryonic stem cells?
they are pluripotent and can give rise to any tissue. Adult stem cells can only give rise to a limited number of tissues.
What are induced pluripotent stem cells?
Embryonic stem cells with a patients genetic material introduced via laboratory.
What are labile tissues?
tissues that continuously lose cells and replace them by proliferations of mature cells and replacement of mature cells by stem cell proliferation. Ex: linings of mouth, gastrointestinal tract, bladder, vagina, cervix, uterus, fallopian tubes, exocrine gland ducts, and bone marrow.
What are stable tissues?
Tissues composed of quiescent cells capable of proliferation, but not normally called onto proliferate. Ex: kidney, liver, pancreas, smooth muscle tissues, brain, and heart.
Which type of tissue would you expect to be vulnerable to radiation injury: labile, stable, or permanent?
Labile, because they are constantly reproducing.
What is epidermal growth factor (EGF)?
growth factor that promotes fibroblast migration and proliferation.
What does FGF do?
fibroblast growth factor stimulates fibroblast migration and proliferation, as well as monocyte chemotaxis and angiogenesis.
What does PDGF do?
platelet-derived growth factor promotes fibroblast migration and proliferation along with monocyte chemotaxis and collagen making. It is most prevalent early in the process when blood vessel disruption allows platelet contact with extracellular matrix.
What does TGF-beta do?
transforming growth factor stimulates fibroblast migration, monocyte chemotaxis and collagen making. It is more prevalent later in the course of repair.
Which growth factors is monocyte chemotaxis mediated by?
PDGF, FGF, and TGF-beta
Which growth factors is fibroblast migration promoted by?
PDGF, EGF, FGF, and TGF-beta
Which growth factors is fibroblast proliferation mediated by?
PDGF, EGF, FGF, TGF-beta
Which growth factors is angiogenesis mediated by?
FGF and VEGF
Which growth factors is collagen synthesis stimulated by?
PDGF and TGF-beta
What are basement membranes composed of?
type IV colagen, laminin, heparan sulfate and proteoglycans.
What does the interstitium underneath epithelium contain?
fibrillar collagen, fibrillin, elastin, hyaluronic acid and proteoglycans.
What are all types of collagen composed of?
3 polypeptide chains braided into a ropelike triple helix
