Exam 2 Flashcards
Cardinal signs of inflammation
Erythema (redness), Edema (swelling), heat, pain, loss of function
Local edema
effective host defense: leukocytes recruitment, bacterial containment, bacterial killing, limited damage to host tissues
systemic edema
Organ injury: hypotension, acute lung injury, acute kidney injury, DIC (Dissemination intravascular coagulation), death
Chronic inflammation
result of prolonged stimulus, destructive, fibrous tissue proliferation (impacts function, body thinks its helping)
tissue repair
vascular endothelial cells (form new blood vessels), myofibroblasts (shrink and contract the wound site) and fibroblasts (produces collagen) proliferate within the wound
Fibronectin
early protein to promote formation of scaffolding to provide tensile strength and “glue” to hold extracellular matrix substances and cells together.
Collagen
most important fibrous protein for structural and tensile strength, glue producer
Type I collagen
the main component of mature scars and also predominant in strong tissues such as tendons and bones
Type II collagen
assembled into thin supporting filaments and predominant collagen type found in cartilaginous tissue
Type III collagen
prevalent in newborns & early scar formation that is progressively remodeled into Type I with cross links to provide greater strength to scar tissue
Type IV collagen
not assembled into fibers, form basement membrane to which epithelial, endothelial, & mesenchymal cells are anchored
Tissue contractures
normal process that contributes to approximation of wound edges, excessive shrinkage results in contractures
Remodeling Phase
remodeling or maturation phase may be initiated as early as 14 days post injury, relatively slow process in connective tissues and may last up to a year or more, shift from type III to type I
Inflammation
protective response to injury, process in which liquid, chemicals, and cells are brought into an injured area to remove stimuli, cellular debris, and initiate the healing process. If prolonged, damage/death to healthy tissue
Contusion
muscle is subject to a sudden, heavy compressive force
Strain
excessive tensile forces lead to overstraining of the myofibers most commonly at the myotendinous junction
lethal injury
regeneration only if basement membrane is intact
Excessive scar tissue
mechanical barrier for muscle fiber regrowth
muscle regeneration (after transection)
muscle fibers regenerate by growth from undamaged stumps or by growth of new independent fibers
muscle regeneration (contused or strained muscle)
capable of self-repair, process is slow and often incomplete. Results in loss of strength and high rate of reinjury
Muscle remodeling
14 days post injury, regenerating myofibers and maturation of new myofibers, revascularization
Tendon and Ligaments
78% water, 20% collagen, 2% glycosaminoglycans (proteins), sustain high unidirectional tensile loads, transfer forces, provide flexible support. Greatest risk when forces are rapid and oblique, presence of degenerative changes. Thicker tendon = greater tensile strength
Inflammation & Proliferation of tendons and ligaments
Hemostasis (clot formation), proliferation begins 2-3 weeks after injury
Maturation and remodeling of tendons and ligaments
begins around week 3 after the initial injury, type III collagen is replaced with type I collagen, fibers realign with tensile forces
Natural and remodeling of tendons and ligaments timeline
Healing lasts 12-16 weeks to manage basic stressors, 24 weeks strength is 40% to 60% of healthy tendon, 40 to 50 weeks to gain normal strength.
Ligament injuries
grade 1 is stretching and small tears, grade 2 is a larger tear, grade 3 is a complete rupture. Ligaments have poor healing response
Healing of bone phases
- Hematoma formation
- fibrocartilaginous callus formation
- Bony callus formation
- Bone remodeling
Bone inflammatory stage
bleeding occurs resulting in hematoma formation
Bone reparative stage
begins next few weeks after Injury, repair lasts between 6-12 weeks, osteoclasts (bone macrophages), osteoblasts (produce bone matrix). poor nutrition, smoking, and immobilization can delay healing time.
bone remodeling phase
begins once union has occurred, no movement. Ends when bone returns to normal
Rehab of repaired soft tissue (tendon or muscle rupture)
During the proliferation phase (usually 5 to 28 days after tendon injury/repair), controlled passive movement is allowed
4-8 weeks after injury/repair active range of motion is initiated with controlled movements
at 8 weeks, resistance with weights, rubber tubing, elastic bands can begin
at the end of 12 weeks, if there has been no complications, full force muscle contraction can be tolerated
Rehab of repaired soft tissue (muscle strain)
As soon as pain and swelling subside, a program can be initiated to recover range of motion, strength, and endurance
return to sports is considered safe when there is an 80% return of strength compared to noninvolved side.
Phases of an immune response
- Recognition (immune system recognizes an intruder)
- Amplification (complement cascades, production of soluble factors, recruitment of WBC “army”)
- Effector phase (Removal of antigens by various means)
- Termination phase (The immune system stands down)
- Memory (generation of long-lived T- & B-lymphocytes)
Innate Immunity
organs, tissues, and cells of the immune system that you are born with, first line of defense, managing most threats. Non-specific (does not recognize one pathogen form another) non adaptive (does not remember encounter)
Acquired immunity
immunity that develops during your lifetime
