• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

image

PLAY BUTTON

image

PLAY BUTTON

image

Progress

1/21

Click to flip

Card Range To Study

through

21 Cards in this Set

  • Front
  • Back
What are the three main categories that result from a wound, and what differentiates the two results of an acute injury?
Regeneration, Healing (scar formation), Fibrosis;

Regeneration occurs when there remains an intact tissue framework (cell matrix), if the tissue framework is damaged (deep wounds) then only healing/scarring takes place
What substance is involved in scar tissue formation? what secretes it?
Collagen Type 1; fibroblasts in ECM
What are the cells that are current in G0, but can re-enter the cell cycle?
quiescent cells (e.g. hepatocytes)
When a stem cell is triggered to proliferate and differentiate in wound healing, do both cells differentiate?
No. one remains a stem cell (undiff.)
What are the two "components" of the cell-matrix and subcomponents involved in wound healing?
BM: preoteoglycans, laminin, Type IV collagen

ECM: Type 1 collagen, elastin, proteoglycans
Are there stem cells in the liver?
Yes! that's why the liver can regenerate; located between bile ductiles and hepatocytes --> express cytokeratin 7
What happens to the quiescent stellate cells in the space of disse upon repeated episodes of cell death leading to abnormal regeneration and scarring?
they become active myofibroblasts and form a dense extracellular matrix.
What happens or is targeted in Days 2-3 of a wound?
Re-epithelialization (EGF)

and fragments of ECM -->
What is proliferation of fibroblasts and ingrowth of new blood vessels in ~Days 4-7 in wound healing?
Granulation tissues (very different from granulomas)
where do newly regenerated capillary networks come from?
existing vessels
what two factors predominantly cause angiogenesis, what secretes them?
VEGF & TGF-a (activated macrophages)
In a mature wound, what happens(ed) to all the capillaries, fibroblasts and macrophages?
apoptosis
in a mature wound, what causes contraction of wound?
myofibroblasts (differentiated, trying to close the wound)
what is responsible for breakdown of the collagen and extracellular matrix in remodeling? why?
matrix metalloproteinases; increase/regain immobility
what is THE most important factor in wound healing?
TGF-beta (beta builds)
what is responsible for the tensile strength of collagen?
triple helix (in Golgi), then cross-linking in ECM --> now *fibrils* --> restores 80% of normal tensile strength (takes 6 months!)
In ECM repair, what is necessary for the hydroxylation of proline?
Vitamin C
What does infection do to wound healing?
Impairs. Shifts back toward inflammatory stage (from fibrotic) and further damages host tissue.
What is the most important function of EGF?
epithelial proliferation
What is the most important function of VEGF?
angiogenesis
What is the most important function of TGF-B? (2)
fibroblast migration/proliferation & collagen sythesis