Injury Response Process Chapter 10 Why do we

Injury Response Process Chapter 10

Why do we care about this process? • We must have a basic understanding of how the body responds to an injury.

Great Adaption Syndrome (GAS) • 1. Alarm Stage • 2. Resistance Stage • 3. Exhaustion Stage

GAS: Alarm Stage • Flight or fight response • Body tries to thwart effects of the stressor by readying defense systems • Increase blood supply to areas that need it • Cortisol is released to regulate inflammation, stimulate cellular activity, and prepare the body to deal with trauma.

GAS: Resistance Stage • • Longest phase Plateau in body’s adaption to the stress Body continues to adapt to the stressor Body achieves physiological resistance

GAS: Exhaustion Stage • When body can no longer withstand the applied stress; failure occurs. • Result: traumatic or overuse injuries

GAS: Relationship to Trauma • Beneficial vs. Harmful stress • Harmful may be… – Too much force in a short period of timemacrotrauma – Repeated, low intensity forces- microtrauma

GAS: Relationship to Trauma • Amount of stress applied to body must be of proper intensity and duration for body to develop physiological resistance • To balance + and – stress, body adapts: – Wolff’s Law: applying enough stress but not too much – Hypertrophy: increase in muscle cell size – Remodeling of collagen fibers (scar tissue): apply stresses so will align properly

Definitions: • • • Ischemia: decreased blood supply Hypoxia: lack of oxygen supply Inflammation: tissue reaction to injury Edema: excessive accumulation of fluids Hemorrhage: bleeding

Injury Process: 2 Parts • Primary Reaction – Tissue destruction associated with the traumatic force • Secondary Damage – Cell death caused by blockage of oxygen supply to the injured area – Enzymatic damage and mitrochondrial failure

Three Phases to Healing • 1. Acute Inflammatory Response • 2. Proliferation Phase • 3. Maturation (Remodeling) Phase

Acute Inflammatory Response • Delivery of phagocytes and fibroblasts into the area • Formulation of granulation tissue: isolates the trauma) • Histamine released (increase capillary permeablity)- results in redness, heat, swelling

Inflammation • Body’s defense mechanism • Body’s reaction to cell injury or death • Triggered by mechanical trauma (spraining a ligament, bacterial invasion, chemical irritation, or burns)

Do we want inflammation? • Essential part of the healing process • However, if the duration or intensity of the inflammation is excessive, the process becomes detrimental and chronic inflammation becomes a debilitating event • Body overreacts to trauma

Purpose of Inflammation • To control the effects of trauma and return the tissue to its normal state • Initially… contains, destroys, dilutes injurious agents and localizes damage • Pain that follows… alerts the athlete that damage has occurred • Muscle guarding: “Splints” the area

Cardinal Signs of Inflammation • • • Heat Redness Swelling Pain Loss of function

Proliferation Phase • 72 hours-3 weeks • Number/size of fibroblasts increase • Ground substance and collagen to collect in injured area (scar tissue) in preparation to rebuild injured area.

Proliferation Phase • Revascularization: proteins produce new capillary beds and granulation tissue. • Fibroblasts lay down collagen to form seal over injured area and extracellular matrix is developed (mostly water content to reduce friction) • Collagen (Type III) is laid down haphazardly; controlled stress caused fibers to arrange themselves more orderly.

Maturation Phrase • 3 weeks- 1 year • Collagen and fibroblasts align themselves and attempt to adapt to original tissue orientation. • Very important to apply controlled stress in this phase to properly align collagen.