Lecture title - Repair and regeneration
70 important questions on Lecture title - Repair and regeneration
What are the three tissue injury outcomes
2. Regeneration
3. Repair
What is resolution (tissue injury outcome)?
No tissue damage = no damage to original architecture of tissue
What is regeneration (tissue injury outcome)?
Reconstruction of original architecture
May leave no residual trace of injury
- Higher grades + faster learning
- Never study anything twice
- 100% sure, 100% understanding
For my 1st exam, I got a C. Then, I started looking for ways to learn better, and I came across Study Smart. Since then, I have scored an A+, A, A-, and another A. I highly recommend it to everyone who wants to hear it. I am so happy with it!!
I was struggling to finish all my first-year subjects for three years. Then I discovered Study Smart, which helped me to complete all of them within three months.
Because of StudySmart, things are going well in many ways. Before, I always had study stress and no time for anything. Now I feel calm and confident (because of the program). I used to score a B, and now I usually score an A or A+.
Hey Chris, I really want to thank you very much for developing the platform, I usually got around C for my exams, now I scored an A+, an A and a A- !!
Since using Study Smart, my average has increased significantly. I even completed a statistics course with an A+ while I'm bad at statistics. I took on extra classes this year because of Study Smart. Thanks so much!
Ever since I started studying with StudySmart, I have passed all my exams! No more re-sits! At first, I was happy with a pass, and now I only get good grades. Many thanks!
I aced all the courses I studied with Study Smart. For law, I first scored a D, and now an A! I’m 100% sure that I’ll pass all the courses I study with Study Smart.
I always thought I studied well. My grades were fine. I could never have imagined that applying these study skills would have such a huge and direct impact on each stage, my speed, and the pleasure I have in learning.
For the first time, I finally feel confident about the way I learn. I have the perfect overview and have made significant progress in terms of speed and the grades I get. Thanks, Chris!
I immediately started to enjoy learning again, and my grades soared. All of a sudden, everything went better. I highly recommend Study Smart to all students..
Being able to create my materials online made the process of studying so much smoother and quicker. I no longer have to spend a considerable amount of my time developing my summaries.
At first, my notes were a mess. Now I use Study Smart to take my notes in a perfectly structured way. It helps me to save a lot of time and do other things I enjoy.
Students that study with Study Smart get better grades. The system applies all the learning methods so that both well-performing students and students who struggle perform much better.
Hi Chris, I would like to thank you very much. Last year I scored C on a course, and this year I got an A+ thanks to your method! Thank you very much!
The most considerable effect is that my child is more enthusiastic about school! Every parent wants their children to be happy at school. Study Smart made it happen.
In high school, I failed several exams, and that has really changed now. I actually needed this tool very much back then. Since I started studying with StudySmart, I haven't had any Ds. My average score is now an A, and those are results I would have never had in the past.
With my old method, I passed only 3 out of 8 courses. However, since I started taking my notes digitally in Study Smart, I have passed all my lessons on the first try. For me, StudySmart takes away the stress of wondering if I will give or not.
Thanks to StudySmart, I passed all my exams and with better grades than before! On top of that, I have mastered a perfect study method now, which I am confident will help me earn my degree.
What is repair (tissue injury outcome)?
May lead to scar
Complex tissue architecture may not be reconstructed
What is needed to resolve damage to the epithelium but not the underlying tissue?
What is needed to resolve a more severe injury that involves damage to the epithelium and the connective tissue?
Which stage of the cell cycle are stable/quiescent cells in when they are not proliferating?
When is the restoration of normal tissue architecture possible?
What type of damage can cause scarring from restoring the normal tissue architecture?
How are injured cells of the epithelia restored?
What determines whether regeneration of the epithelia succeeds?
2. Integrity of stem cells
3. Underlying support, like the basement membrane, must be intact
(basement membrane guides epithelial regeneration)
What is the regeneration of parenchymal tissue with stable cells like?
Why does repair by scarring happen?
2. Damage to permanent/non-dividing cells
What are the two possible scenarios of repair if the lost tissue can't be replaced?
2. Regeneration of some residual cells + scar formation
List the overall steps of scar formation with durations of each step
2. Cell proliferation (up to 10 days) = covering of wound by epithelial cells, angiogenesis by endothelial and vascular cells, production of collagen fibres that later form scar = granulation tissue production
3. Remodelling (2-3 weeks - months) = reorganisation of connective tissue deposited by fibroblasts for fibrous scar formation
What is the purpose of remodelling for scar formation?
What is a granulation tissue?
What are the histological features of granulation tissue?
2. Fibroblasts and myofibroblasts = spindle-shaped cells
3. New and mature collagen = blue stain
Compare the histological characteristics of granulation tissue and mature scar
Mature scar = dense collagen, scattered vascular channels
What induces angiogenesis?
Where do fibroblasts enter a wound from during repair?
What cell type can some fibroblasts differentiate into during healing?
What protein is expressed by myofibroblasts?
What is the purpose of increased contractile activity during healing by myofibroblasts?
What is the purpose of wound contraction?
Explain how wound contraction works
2. Granulation tissue as a whole contracts to draw the surrounding tissue together
What are the possible problems that can occur due to wound contraction?
What are the problems of wound contraction after burns to skin?
Define extracellular matrix (ECM)
What are the major functions of the extracellular matrix (ECM)?
2. Control of cell proliferation - growth factors, signalling
3. Scaffold (temporary physical framework) for tissue renewal
What are the general components of the extracellular matrix (ECM)?
2. Gels - proteoglycans, hyaluronan
3. Adhesive glycoproteins / link proteins - fibronectin, laminin
What do the fibrous structural elements of the extracellular matrix (ECM) do?
What do the gels of the extracellular matrix do?
What do the adhesive glycoproteins and link proteins of the extracellular matrix (ECM) do?
How does the role of the fibroblasts and new vessels change as repair progresses?
When is collagen synthesized during wound healing?
What is granulation tissue scaffolding ultimately converted to?
What kind of granulation tissue turns forms a pale, avascular scar?
What growth factors are involved in extracellular matrix (ECM) deposition during tissue repair?
Fibroblast growth factor (FGF)
Platelet derived growth factor (PDGF)
What is the purpose of extracellular matrix deposition?
What is the main purpose of tissue remodelling after scar formation?
How does wound strength increase during tissue remodelling?
What does the balance between ECM synthesis and degradation influence?
What enzymes are responsible for ECM degradation during tissue remodelling?
Summarise wound healing
2. Regeneration of parenchymal cells
3. Migration and proliferation of connective tissue
4. Synthesis of ECM protein
5. Remodelling of connective tissue
6. Collagenisation and acquisition of wound strength
What is healing by first intention (also called primary union)?
What is healing by second intention (also called second union)?
Compare first and second intention wound healing
- little to no tissue has been lost
- opposed edges
2nd intention
- tissue has been lost
- unopposed edges
- more intense inflammatory reaction
- more granulation tissue
- contraction of wound
Why is there a more intense inflammatory reaction in second intention than first intention?
Why are there larger amounts of granulation tissue in second intention than first intention?
What is the determining factor of whether a wound heals by first or second intention?
What is the strength of the wound at week 1-2?
What happens to the strength of the wound for the 4 weeks after week 1-2?
After 3 months, what happens to the strength of the wound?
Which skin cells regenerate efficiently after superficial injury?
Why might some structures of the skin, like hair follicles and sweat glands, not return after skin injury?
What distinguishes a GIT mucosal erosion from an ulcer in healing?
Which tissue forms a callus during healing?
Summarise healing in bone from a fracture
2. Callus formation
3. Callus and woven bone replaced by lamellar bone
4. Bone remodelling
What are the factors that can delay bone healing?
Interposed soft tissue (unwanted tissue between two structures)
Gross misalignment (anatomically inappropriate bone healing)
Infection
Which organ has exceptional regenerative capacity via hepatocytes?
What determines whether the liver heals normally or forms cirrhosis?
When does liver form fibrous scars or regenerative nodules from healing?
What are the local host factors that modify the healing process?
Mechanical factors (early motion, pressure)
Foreign bodies (sutures, fragments, bone)
Size, location, and type of wound
What are the systemic host factors that modify the healing process?
Metabolic status (diabetes)
Circulatory status (what the blood vessels bring to the injured site)
Hormones
What is a chronic wound and why does it happen?
1. Mainly due to local ischaemia
2. Systemic factors (internal, body-wide condition)
Why does a deficient scar form?
Forms due to mechanical stress like coughing and vomiting
Compare a hypertrophic scar and a keloid
Hypertrophic scars are local and usually regress overtime.
Keloids form beyond wound boundaries and don't regress.
What causes replacement of normal tissue by fibrosis?
Explain the process of replacing of normal tissue by fibrosis due to persistent tissue injury.
2. Macrophages and leukocytes produce cytokines to heal
3. Fibroblasts and myofibroblasts migrate and proliferate + collagen and other ECM proteins are deposited
The question on the page originate from the summary of the following study material:
- A unique study and practice tool
- Never study anything twice again
- Get the grades you hope for
- 100% sure, 100% understanding
