Chapter 4-Cell Proliferation, Tissue Regeneration & Repair Flashcards
What is the difference between tissue regeneration in Parenchymal and Stomal tissue?
Parenchymal tissue:
- the functional parts of an organ or body
- replaced with cells of same type, often left with no signs of any precious damage
Stomal tissue:
- the supporting tissue of organs, namely, the connective tissues (BV, fibroblasts, nerve fibers)
- where scars are seen
Compare cell proliferation with cell differentiation.
PROLIFERATION:
- process of increasing cell numbers by mitotic division
- the dominant process
- occurs during cellular stage of inflammatory response
DIFFERENTIATION:
-process whereby a cell becomes more specialized in terms of structure and function
The more specialized and differentiated cells are the less they are able to proliferated.
What is the main structural protein of various connective tissues?
Collagen
What are growth factors?
Proteins that drive proliferation.
What are the 5 stages of the cell cycle?
G1 - post mitotic phase where DNA synthesis ceases and RNA & protein syntheses and cell growth take place
S - DNA synthesis : gives rise to 2 sets of chromosomes
G2 - pre mitotic phase where DNA synthesis while RNA & proteins are synthesized
M - mitosis: nuclear division
G0 - resting state of the cell; cell exit the cell cycle
*Sequence is complex = all of these are needed to have this sequence happen
What is Proliferative Capacity of Tissues?
- Depends on what type of tissue it is
- The capacity for regeneration varies with tissue and cell type.
- Divided dependent on the ability of their Parenchymal cells to undergo regeneration.
What are the 3 divisions of body tissues?
- Continuously doubling: (continuously regenerating) epithelial, GI tract, blood, bone marrow
- Stable: (division occurs less often) liver, kidney, smooth muscle, vascular endothelial and fibroblast cells
- Permanent tissues: nerve, skeletal muscle, cardiac muscle - once damaged they are replaced with fibrinous bands/scar tissue and lack function
What is the goal of all tissue repair?
Fill in gap
Try to get structural integrity back and continuity
Describe the two types of tissue repair
Tissue regeneration:
- angiogenesis: occurs first during this process by connective tissue deposition
- involves the replacement of the injured tissue with cells of the same type leaving little evidence of the previous injury
Fibrous tissue repair:
- occurs when regeneration can’t
- repair occurs by the replacement with connective tissue, a process that involved generation of granulation tissue and formation of scar tissue
As a nurse what should you consider when it comes to a patient who is currently going through the wound healing process?
Protein (red meat) Calories Glucose (glycemic control for diabetics) Oxygen Blood flow GI control (nausea)
What is granulation tissue?
- Good, means wound is healing
- Glistening meat red, gooey, beefy red
- Do not rub off, pat to clean
What are the two types of cutaneous wound healing?
Primary intention and secondary intention
What is Primary Intention?
Sutured surgical incision or cut, stitched up nice and neat
Heals quickly
What is secondary intention?
-heals from the bottom up forming granulation tissue.
Larger wounds which have a greater loss of tissue and contamination
What are the 3 phases of wound healing?
- Inflammatory phase
- Proliferative Phase
- Remodeling phase
What are some factors that affect wound healing?
Nutritional state Blood flow and oxygen delivery Impaired inflammatory and immune response Infection Wound separation (dehisce) Foreign bodies Elderly
What are some specific considerations to take when dealing with an elderly patient with a wound?
Decreased thickness in skin Less collagen Loss of elasticity Alterations in the wound healing process Slower re-epithelialization comorbidities
Regeneration
- tissue repair
- parenchymal cells are replaced with cells of the same type and often times without any evidence of repair
What are stem cells?
- mother cells
- undifferentiated = can become anything
- found in umbilical cord
- made in bone marrow
- can self renew themselves
- can split themselves so they are asymmetric proliferation: one half stays the same and the other half goes on to do something specific
Cyclines
Proteins that BIND and CONTROL the entry and progression of cells through the cell cycle
-Bind and activate proteins called CyclineDependentKinases
Describe the Inflammatory Phase of wound healing.
- prepares the wound environment for healing:
a. at time of injury
b. clot formation
c. WBCs migrate to area (macrophages produce growth factor to induce proliferation)
d. granulation MUST occur before the next phase can happen. - Nuetrophils kill the bad stuff, macrophages ingest the debris and stimulate proliferation.
Describe the Proliferation Phase of wound healing.
- new tissue is built to fill the wound space
a. epithelialzation (skin cells start to be made) 2-3 days after injury
b. focus on building new tissues to fill in the wound space with the migration of skin cells over that area.
c. fibroblasts (stimulate growth of new blood vessels) KEY CELLS that stimulate the growth of new cells/blood vessels
Epithelialzation
new skin cells are made
Describe the Remodeling Phase of wound healing.
- continued remodeling of scar tissue may take a while
- Can take 3 weeks up to as long as 6 months after
- Decrease in vascularity
a. stronger tissue (tensile)
Tensile
strength
Dehisce
wound opens up
comorbidities
several different issues to create complications
