Tissue Repair Flashcards
First step in tissue repair
inflammation
What is tissue repair and what does it attempt to do?
- response to cellular injury
- attempts to maintain normal body structure (homeostasis) and function
2 forms of Tissue Repair
- regeneration
- replacement
What occurs during Regeneration?
injured cells are replaced with cells of the SAME tissue type
no scars
What occurs during Replacement?
- buildup of connective tissue
- replaced with different cells of CT
- cause scars
What are the 2 primary structures of tissue Regeneration? What do they do?
parenchymal
- cells that perform the function of the targeted organ
- ex: liver’s purpose is to metabolize. Hepatocytes do that job
stromal
- structural cell: support CT, blood vessels, nerve fragments, and extracellular matrix
What determines the cell’s ability to regenerate?
What are the different regenerative cell types?
the cell’s ability to divide - mitosis
- Labile cells
- Stable cells
- Permanent/fixed cells
Labile cell characteristics and examples
- can divide QUICKLY
- skin cells
- uterus
- GI tract
Stable cell characteristics and examples
- cells stop dividing after organ stops growing
- stimulation is required for continued growth
- liver cells
Permanent/fixed cell characteristics and examples
- do not undergo division
- cannot regenerate
- nerve, heart, or brain cells
When does Fibrous tissue repair occur?
- replacement tissue repair
- occurs after a severe injury: deep laceration
- tissue is replaced with CT
What is Granulation and what is the process?
Process of “filling” a deep wound
- angiogenesis - growth of new blood vessels from preexisting blood vessels
- fibrogenesis
- formation of scar tissue
What occurs during fibrogenesis?
- activation of fibroblasts - proliferation/build up of fibroblasts
- formation of extracellular matrix- when activated, release the components that become extracellular matrix - helps make skin tough and durable
Steps to formation of scar tissue
- emigration and proliferation of fibroblasts
- deposits of extracellular matrix components
- deposit into wound area
- no more blood flow, but continuous build up of collagen
What are 2 components that regulate the healing process?
- chemical mediators
- growth factors