4 - Tissue Inflammation, Healing, and Repair Flashcards
True or false: healthy tissue can resist changes in their shape?
True
True or false: if a tissue is not used it takes more stress to produce the same amount of strain/deformation of that tissue
False, it takes less stress to cause the same amount of strain if a tissue goes unused
Tendons and ligaments both have changes associated with ____?
Age
When cartilage starts to breakdown there is a disruption of what?
Synthesis and degradation in the ECM
If cartilage is not loaded what happens?
It deprives the tissue of the processes required for healthy functioning (ie. no compression, no movement of nutrients in or out).
Also leads to changes in the collagen, there are weaker bonds and the ECM becomes unorganized (it all starts to look like the middle zone, mesh).
What occurs when there are sustained repetitive loads over time?
Microtrauma
What occurs when a bone is not loaded or doesn’t experience mechanical forces?
Osteopenia
Slide says osteogenesis but that is the formation of bone which only happens if you load bones
What are some of the things that happen to muscles as you age?
Cross sectional area is reduced, their ROM is decreases and the power they can produce is also reduced
What happens to muscles if they are injured or immobilized?
They decrease in force production
What are some ways muscles can breakdown?
Contusions Strains Inadequate flexibility Inadequate strength or endurance Uncoordinated muscle contraction Insufficient warm up Poor rehab
What happens to tissues with prolonged corticosteriod use?
Weakens passive tissues and there is an abnormal turnover collagen fibers
True or false: Non-steriodal anti-inflammatory drugs do NOT interfere with the tissue healing process
False, they do interfere. The related healing potential is weaker when NSAID’s are taken
Why as PT’s should we understand the healing process?
We need to recognize the S&S associated with different healing phases so we can effectively incorporate the right treatment at the right time
What is a parenchymal cell?
A cell that carries out the function of a tissue or organ
What is an endothelial cell?
They are inner blood vessel cells that form new capillaries
What is a platelet?
An irregular disc shaped element in the blood to assist with clotting
What are leukocytes?
White blood cells involved in the inflammatory process
What are the two types of leukocytes
Mononuclear or Agranular
and
Polymorphonuclear or Granular
What are the subtypes of Agranular/Mononuclear Leukocytes?
Monocytes/macrophages, and lymphocytes
“The Defenders”
What are the subtypes of Granular/Polymorphonuclear leukocytes?
Esinophils, basophils and neutrophils.
“The Killers “
What are fibroblasts?
They are flat cells in the dermis of the skin and structural tissues (ligaments and tendons)
What is a fibroblasts function during injury
They synthesize collagen for wound closure (help with forming a scar) and they also help with ECM remodelling (degradation and production of collagen)
True or false: the healing process is a continuum
True
What are the three stages to the healing process?
Inflammatory Response
Fibroblastic/Repair Phase
Maturation/Remodeling Phase
What characterizes the inflammatory response?
Redness, swelling, tenderness, increased temp, loss of function, typically 0-4 days after injury
True or false: after an injury homeostasis can take hours to days to occur
False, homeostasis occurs within seconds to stop blood loss
What characterizes the fibroblastic/repair phase?
Deminishing pain and tenderness, gradual return to function, typically 2 days - 6 weeks after initial injury
In the fibroblastic phase one of two things can happen, what are those things?
Regeneration - process to replace necrotic cells with new ones of the same type
OR
Reparative - process to replace necrotic cells with collagen to form scar tissue
Whether a regenerative or reparative process occurs depends on two things, what are they?
The extent of the injury and the type of tissue (whether the cells can divide or not)
What occurs during revascularization?
The lack of O2 stimulates the growth of capillary buds into the wound which means the wound can now heel aerobically (with O2). The new blood flow delivers nutrients to tissue regeneration however, the vessels tend to be leaky so the tissue around the injury appears wet.
(Increase/Decrease)
When forming a scar, as more collagen is being laid down the strength of the scar is ______. But as the strength of the scar _____ there are _____ fibroblasts so there is _____ collagen being laid down
strength of the scar is increasing. But as the strength of the scar increases there are decreased amount of fibroblasts so there is a decreased amt of collagen
The maturation/remodeling phase is characterized by what?
A strong contracted scar, increasing strength and full return to function. Could be 3 weeks to 2 years after initial injury
What are the intrinsic factors that impact healing?
Extend of Injury Edema Hemorrhage Poor Vascular Supply Tissue Separation Muscle Spasm Atrophy Scarring
What are the systemic factors that impact healing?
Age Obesity Malnutrition Hormone Levels Infection General Health
What are the extrinsic factors that impact healing?
Drugs Dressings Temperature Physical Modalities Exercise
If there is a cartilage injury that does not reach the subchondral bone will it heal?
No, it becomes necrotic and dies. Because cartilage is avascular
If there is a cartilage injury that does reach the subchondral bone does it have a chance at healing?
Yes, because then the blood supply of the bone can help with healing. However, it will not heal back as cartilage, it will be biochemically and mechanically different
