Cell Injury, Repair, and Wound Healing Flashcards
List the phases of cutaneous wound healing.
- Injury
- coagulation
- early inflammation
- late inflammation
- proliferation
- remodeling
If you undergo an injury, what must be done initially so that proper healing can occur? What cells are responsible for this?
debridement (cleaning up the wound); macrophages
What are some roles of macrophages in wound healing?
debridement (removal of injured tissue and debris)
antimicrobial activity
chemotaxis and proliferation of fibroblasts and keratinocytes
angiogenesis
deposition and remodeling of ECM
What are two ways in which tissues can repair themselves? What’s the most common way?
regeneration
scar formation** most common
After a corneal abrasion, via which mechanism is the eye repaired?
regeneration through corneal stem cells of the limbus area that migrate out and heal the area
What cells of the intestine are responsible for regeneration?
crypt cells
4 places that have regenerative “adult” stem cells
- skin
- intestine
- liver
- cornea
These cells are pluripotent and arise from blastocyst. Can be cultured to produce hepatocytes, neurons, cardiomyocytes, pancreatic islet cells, etc
embryonic stem cells
What is this: resolution of normal structure. Give an example.
regeneration; liver regeneration after partial hepatectomy, healing of lungs after pneumonia.
What is this: scar formation, organization of exudate. Give an example.
healing; myocardial infarction, deep excisional wounds
What is synonymous with scarring and occurs in chronic inflammatory diseases?
fibrosis
Can cardiac myocytes regenerate? So how must they heal? What is layed down during the healing? Can this contract?
no; they heal by scarring; lay down collagen; cannot contract —> can lead to heart failure
Tissues with permanent cells (myocytes or neurons) can replace dead cells with (blank) only
scar tissue
List three types of cells
- continuously cycling (ex: epidermis)
- quiescent or stable cells (ex: hepatocytes)
- nondividing permanent cells (ex: cardiac myocyte or neuron)
Sources: activated macrophages, salivary glands, keratinocytes, and many other cells
Functions: mitogenic for keratinocytes and fibroblasts, stimulates keratinocyte migration, stimulates formation of GRANULATION TISSUE
EGF –> epidermal growth factor
Sources: mesenchymal cells
Functions: chemotactic for neutrophils, macrophages, fibroblasts, and smooth muscle cells; activates and stimulates proliferation of fibroblasts, endothelial, and other cells, stimulates ECM protein synthesis
vascular endothelial growth factor
Function: chemotactic and mitogenic for fibroblasts; stimulates angiogenesis and ECM protein synthesis
fibroblast growth factor or transforming growth factor