Term
True or False
True resolution cannot occur with chronic inflammation |
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Definition
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Term
| What determines the extend of regeneration? (3) |
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Definition
ability of cells to divide
number of surviving cells
whether there is a surviving tissue framework to allow normal tissue structure |
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Term
| Skin & mucosal epithelial cells and hematopoetic cells of bone marrow are examples of... |
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Definition
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Term
| What are the characteristics of labile cells? |
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Definition
-short life
-rapid rate of division
-divide actively throughout life
-regneration of this tissue is rapid |
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Term
| What are the characteristics of stable cells? |
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Definition
-reversible postmitotic (remain in interphase for years, can divide if necessary)
-require some connective tissue framework to support regeneration of this tissue |
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Term
| What types of cells make up the liver, kidney, pancreas, endothelium etc? |
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Definition
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Term
| How does healing of tissue composed of permanent cells occur? |
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Definition
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Term
| What regulates the net rate of cell proliferation? |
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Definition
CYCLINS motivate replication!
1. ability to replicate
2. balance between proliferative & inhibitory activity (cyclins)
3. balance between rate of proliferation & cell loss |
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Term
| What modifies cyclin activity? |
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Definition
growth factors & hormones upregulate
inhibitory signals can impair proliferation/induce apoptosis |
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Term
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Definition
| replacing normal tissue with dense collagenous connective tissue after injury |
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Term
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Definition
-regeneration is not possible (cell type, not enough cells, framework destroyed)
-acute inflam is unresolved or there is ongoing tissue necrosis |
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Term
| Damage to the intestinal epithelium due to a rotavirus causing villus atrophy is likely to heal by.... |
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Definition
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Term
| Damage to renal tubule epithelial cells is likely to heal by.... |
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Definition
regeneration if damage is mild
scarring if more extensive |
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Term
True or False
Liver cells are more likely to successfully regenerate than kidney cells |
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Definition
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Term
| What are the steps of developing scarring? (6) |
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Definition
1. Debridement
2. Granular tissue formation
3. Angiogenesis
4. Collagenization
5. Maturation
6. Contraction |
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Term
| What is the role of neutrophils in scar formation? |
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Definition
| release enzymes to liquify debris (involved in debridement) |
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Term
| Why is the formation of granulation tissue important? |
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Definition
fills the injured area until more mature tissue can develop
highly vascular |
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Term
| Angiogenesis is important in both.... |
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Definition
| wound healing & developing collateral vessels in instances of ischemia |
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Term
| What synthesizes collagen? |
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Definition
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Term
| Why is collagenization important? |
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Definition
| gives tensile strength to scar tissue |
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Term
|
Definition
replacing granulation tissue with mature connective tissue
-more collagen, less capillaries & inflam cells |
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|
Term
True or False
A fully mature scar is primarily composed of collagen |
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Definition
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Term
|
Definition
a protein which is chemotactic for fibroblasts, helps to 'organize' endothelial cells
-important in granulation tissue formation |
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|
Term
| What causes contraction of a scar? |
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Definition
Early on: actomyosin in some fibroblasts
Later: increased [collagen] |
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Term
| Do lacerations affect the dermis or epidermis? |
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Definition
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Term
| Do burns affect the dermis or epidermis? |
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Definition
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Term
| What differentiates scar formation from healing of skin wounds? |
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Definition
| skin wounds also requires epithelializtion |
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Term
| What is required for healing by first intention? |
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Definition
| wound edges must be brought close together |
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Term
| What are the steps of healing by first intention? |
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Definition
1. Hemorrhage & release of thromboplastin (for clotting & scab formation)
2. Loss of contact inhibition causes basal cells to migrate under scab to cut margins
3. Debridement
4. Angiogenesis
5. Collagenization
6. Maturation
6. Contraction & remodeling |
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Term
| When would healing by 2nd intention occur? |
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Definition
| when tissue damage is more extensive |
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Term
| How is healing by second intention different than first? (3) |
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Definition
-more granulation tissue
-granulation tissue is not covered by epidermis as quickly
-takes longer
-intense inflammation (more necrotic debris)
-wound contraction takes up to 6 wks |
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Term
| What are some complications of healing by second intention? |
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Definition
-increased risk of secondary inflammatory-mediated injury
-more granulation tissue = more scar tissue mass
-keloid formation (hypertrophic scarring)
-great wound contraction = compromised vascularity/function of the tissue
problem if 2nd intention in brain/heart! |
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Term
|
Definition
| abnormal masses of collagen |
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|
Term
| What factors affect effectiveness of wound healing? (7) |
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Definition
nutrition
age
drugs
foreign material
blood supply
size/shape/location of wound
presence of infection |
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