Physiological response to injury Flashcards
What are vascularized tissues?
muscles, skin, bone
What are not vascularized tissues?
cartilage and tendons
What happens immediately to vascularized tissues when damaged?
They undergo a cascade of biochemical events
What are the three stages to tissue repair?
- inflammation
- proliferation
- remodeling
When is the inflammation stage?
Immediately after damage; the first 48 hours
what happens during the inflammation phase?
the body is undergoing inflammation and lots of cellular activity to help kick start healing. Along with that, you want to be mobilizing the injury and the defenses
What is the inflammatory stage referred to as sometimes?
Acute, degeneration demolition phase
How long does the proliferation stage last?
days to a week
What occurs during the proliferation stage?
You are going to be synthesizing new tissue and collagen.
What is the proliferation stage known as?
the post-acute, repair and regeneration stage
What occurs during the remodeling phase?
Long term remodeling and maturation of tissue.
Also, organization of the tissues is going to occur (you have the tissues, they just aren’t organized to be as strong as they could be)
True or false: The inflammatory phase is a cascade.
True
In the inflammatory cascade, what kicks off the inflammatory response?
The arachidonic acid cascade
What are the 4 main molecules released by the arachidonic acid cascade and what do they do?
- Prostaglandin
- Histamine
- Bradykinin
- Thromboxane
They stimulate blood vessels
What comes after the arachidonic acid cascade?
The vascular cascade
What happens during the vascular cascade?
vasodilation, increased permeability, swelling/edema, clotting and coagulation,
hematomas, and ischemia and hypoxia
Why does your body create clots and coagulate?
it is the bodys way of containing the injury
what is ischemia?
impaired blood flow
What is hypoxia
a lack of oxygen
What comes after the vascular cascade?
the coagulation cascade
what happens during the coagulation cascade?
blood starts clotting and blood flow slows down, while simultaneously forming a mesh to contain the area.
what happens after the coagulation cascade?
the leukocyte cascade
what happens during the leukocyte cascade?
White blood cells come in and try to identify and clean out bad pathogens (phagocytosis)
what causes secondary injury?
ischemia, hypoxia, and phagocytosis
what is used to help prevent secondary injuries?
the PRICE protocol
what are signs and symptoms of inflammation and what causes it?
Signs and symptoms: pain, heat, redness, etc.
Causes: increased blood flow
can you have too much acute inflammation?
yes! Inflammation is only good to a certain degree
what is the purpose of acute inflammation?
it is the body’s protective response
What two processes does vascularized tissue undergo?
Regeneration and repair
What process does hypo-vascularized tissue undergo?
degeneration
what is regeneration?
when damaged tissue is replaced with identical tissue and can restore tensile strength completely
what is repair?
When damaged tissue is replaced with scar tissue and there is partial restoration of tensile strength
What is the only tissue to regenerate?
bone
What is degeneration?
The tissue deteriorates to a lower form and there is no regeneration with failed repair; the tissue is less functional than it was before
What are the major cells in the inflammatory cascade?
- Platelets
- Mast
- Leukocytes
- Erythrocytes
- Lymphocytes
- Smooth muscle
- Endothelial
What are the major messengers of the inflammatory cascade?
- Histamine
- Arachidonic Acid (Thromboxane and Prostaglandin)
- Bradykinin
- Complement proteins
What does cyclo-oxygenase (COX) do?
breaks down arachidonic acid into thromboxane and prostaglandins
What does thromboxane help with?
it supports platelet function and helps with hemostasis, coagulation, and clotting
What do prostaglandins help with?
They help mediate the inflammatory response; deals with vasodilation, vascular permeability, and pain
What do lymphatics do within the vascular system?
They help filter out the blood, clean it, and dump it back into the venous circulation
What causes pain (in relation to the vascular system)?
Tissue tension caused by swelling
What is transduction?
the release of fluid (typically leakage)
what is exudation
the release of plasma proteins and cells
what are the three stages of coagulation?
- prothrombinase
- thrombin “burst”
- fibrin clot
what is the key cell to prothrombinase?
platelets
What is the key enzyme in forming fibrin (in stage 2 of coagulation)?
thrombin
what causes the fibrin to clot and thicken during the third stage of coagulation?
fibrinogen
What are the two types of white blood cells?
Neutrophils and monocytes
What is the smaller type of white blood cell?
Neutrophils
What do neutrophils do?
they are the first line of defense and help start the breakdown and clearing out of cells.
what is the negative effect of neutrophils?
they are non selective, so they could damage healthy cells
how long do neutrophils survive for?
about 12 hours
what do monocytes do?
turn into macrophages.
what are the two types of monocytes?
inflammatory and anti-inflammatory
what do inflammatory monocytes do?
they are destructive and are phagocytes
what do anti-inflammatory monocytes do?
they have growth factors and are pro-fibrotic, so they induce fibrosis and help heal
What is the white blood cell response process?
Cytokines are released and activate the endothelium, which signals the WBCs to marginate. Eventually, they firmly adhere to the epithelium
what are the two stages of the leukocyte cascade?
- engulfment/ingestion
- Degradation/digestion
Is pain subjective?
Yes
What are the ABCs of pain?
Affective, Behavioral, and Cognitive
What is the affective pain perception?
Someone’s emotional factors that can affect pain experience (are you emotional)
What is the behavioral pain perception?
how one expresses or controls pain experience (do you cry, scream, internalize it, etc.)
what is the cognitive pain perception?
learned from past experiences or education (you know it will hurt, but you know it will get better)
What are the 3 classifications of pain?
- Nociceptive
- Neuropathic
- Psychogenic
What is nociceptive pain
Pain from tissue damage (injuries)
What is neuropathic pain?
damage to the nervous system
What is psychogenic pain?
mental, emotional, or behavioral origins. There may not be actual damage, but you may be perceiving pain
What is acute pain?
A symptom you have when you have an acute injury.
It is a protective response and usually results in quick recovery
What is chronic pain?
A disease, that has no useful purpose. it is pain that persists beyond the acute stage and could be degenerative.
What is hyperalgesia?
heightened pain. It is when you have an injury and the receptors are very sensitized
What does noxious mean?
something is harmful, paining, or injurious to the body
What is pain sensitivity?
a threshold (lowest level) of a noxious stimulus required to trigger pain response
What is pain tolerance?
the amount of pain a person is willing or able to tolerate
Can you adjust pain sensitivity and tolerance levels?
yes
What are the 3 stimuli that cause nociceptive pain in the body?
- mechanical pressure
- Chemical irritation
- Heat
What does the strength of an impulse depend on?
- Amplitude (how strong)
- Frequency (how often)
- Size of neuron and myelination
What are the two fibers that help transmit pain?
A delta and C fibers
How do A delta fibers transmit pain?
They single first pain, which is acute, sharp and fast.
It phases out quickly
How do C fibers transmit pain?
They signal the second pain, which is slow and chronic.
How does pain get transmitted?
Neurotransmitters get released, cross the cleft, bind to the post synaptic membrane to open the channels, which allows the chemical messengers to send the pain signal to the next fiber.
What do excitatory neurotransmitters do?
Excite pain
What ware examples of excitatory neurotransmitters?
- Substance P
- Glutamate
- Prostaglandin
- Bradykinin
What is the goals of treatment during the inflammatory cascade through therapeutic intervention?
Facilitate the healing process by providing the best environment for repair
What is the goal of protection modalities?
To limit the amount of stress on damaged tissues through protected motion
what is orthosis?
A device designed to support or correct human dysfunction
What is relative rest?
Functional rest. You want to be resting while maintaining fitness.
How can you practice relative rest?
cross-over training and mental practice
what is the procedure for cryo-therapy?
on for 20 minutes, off for 40
what is the goal of “external” compression
To “counter” pressure to hydrostatic pressure in blood vessel or tissue to limit swelling
What are the 3 types of “external” compression techniques?
- Circumferential compression with uniform pressure
- Collateral compression
- Focal compression
What are the goals of elevation?
To reduce hydrostatic pressure in blood vessels, assist with lymphatic drainage, and to redirect swelling away from joints
What is the first order in analgesic pathways?
the site of injury and it’s direct.
what can be done at the first order to help with pain?
cry-therapy (PRICE) and/or an injection with local anaesthetic
What is the second order in analgesic pathways?
ascending and spinal
what is done during the second order of pain control?
Gate control (shut gate to pain), electrical stimulation (block signals), and cry-therapy
What is the third order of the pain control?
direct and descending; supraspinal
What is done during the third order of pain control?
communication and reassurance, cognitive mediation, education, and anything else that can help lessen fear and anxiety
what happens during pre-synaptic inhibition?
the prevention of the release of a neurotransmitter
what happens during post-synaptic inhibition?
The prevention of neurotransmitters binding to receptor sites, inhibition of ion channels, and the prevention of depolarization of the membrane
What is gate control for pain transmission
When the pain signal gets blocked at the second order.
what typically occurs during gate control?
a counter-irritant (sensation) that is a stronger signal from a modality.
do both steroidal and non-steroidal anti-inflammatory drugs interfere with the inflammatory process?
yes
what is the main side effect from steroidal drugs?
Weakening of tensile strength caused by overdosing
What is a complication of NSAIDs?
They can interfere with coagulation
True of false: Most NSAIDs can function as analgesics but not antipyretics
false, they can act as both
what is an analgesic?
a pain controller
What is an antipyretic?
helps control fevers
What do drugs act as in the body?
Enzymatic inhibitors
What specific mediators do drugs inhibit from being produced?
arachidonic acid, prostaglandins, and thromboxane A2
Is the proliferation stage the one with the greatest improvement in strength of wound?
Yes
What is phagocytosis?
The clean up of dead cells and debris by WBCs
What is fibrinolysis?
The breakdown of clots by plasmin
What is angiogenesis?
Capillary sprouting or budding due to RBCs
what is fibrosis?
the building of a “new wall.”
What two processes occur during fibrosis
- Fibroplasia (fibroblasts migrating to damaged area)
- Scar formation (collagen fibers are organized in ground substance)
What occurs during phagocytosis and fibrinolysis?
Plasmin is working as a degradative enzyme, inactivation of coagulation factors, and a digestion of fibrin threads
what is the main factor of angiogenesis?
Vascular endothelial growth factor (VEGF)
What occurs during wound contraction?
The wound closes up (due to strands that pull the margins inward)
What occurs during the fibrotic cascade?
Fibroblasts synthesize and deposit collagen around the areas of the injury
What are the goals of rehabilitation?
To restore ROM and strength, restore function, and proliferation
What are the key things to do to achieve the goals of rehabilitation?
Therapeutic exercises
What happens during tissue remodeling and maturation?
Type I collagen matures and replaces type III to cause an increase in strength
What is collagen maturation?
The reorganization of collagen, this is an on-going remodeling process
