Module 1B - Inflammation and Tissue Repair

Trauma is Greek for what?

Wound

What are the main types of trauma?

Macrotrauma and microtrauma

What is macrotrauma?

Injury caused by a single event

What is microtrauma?

Injury caused by repetitive stress over time

What is an injury?

Harm or hurt to tissue

What is a primary injury?

Main struture damaged

What is a secondary injury?

Other structures damaged due to primary injury

What are the causes of an injury?

- Physical trauma

- Metabolic processes

- Biological processes

- Chemical agents

What factors affect the healing process?

Nutrition, comorbidities, age, status of tissue, chronic disease

What is the goal of a physical therapist in the healing process?

Facilitate tissue healing and protection as needed

What are the three phases of the healing continuum?

1. Inflammatory

2. Proliferative

3. Maturation or remodeling

What is the inflammation phase?

Inflammatory response; prepares wounds for healing

What is the proliferative phase?

Fibroblastic repair; rebuilds damaged tissue and strengthens the wound

What is the maturation phase?

Maturation and remodelling; modifies scar tissue into its mature form

In which phase of the healing process should we really encourage activity?

Proliferative phase

What are some signs and symptoms seen in the inflammatory-response phase?

Redness, swelling, tenderness, pain, increased temperature, loss of function

What are some signs and symptoms seen in the fibroblastic-repair phase?

Diminishing pain and tenderness, gradual return to function

What are some signs and symptoms seen in the maturation-remodeling phase?

Strong contracted scar develops, increasing strength and full return to function

What is the approximate timeline of the inflammatory-response phase?

0-4 days (days 1-6)

What is the approximate timeline of the fibroblastic-repair phase?

2 days-6 weeks

What is the approximate timeline of the maturation-remodeling phase?

3 weeks-2 years

What are the four components of the inflammation phase?

1. Vascular response

2. Hemostatic response

3. Cellular response

4. Immune response

What are the four goals of the inflammation phase?

1. To defend/protect the body against foreign substances

2. To remove dead and dying tissue to allow for repair

3. To form fibrin lattice for wound strength

4. To recruit endothelial cells and fibroblasts for repair

TRUE or FALSE - The inflammatory phase is normal and necessary and a prerequisite for healing; though can be harmful

TRUE

What are the events of the inflammatory phase events?

1. Injury

2. Structural changes

3. Vascular response

4. Chemical mediation

5. Permeability changes

6. Leukocyte migration

7. Phagocytosis

What are the 5 cardinal signs and symptoms of the inflammatory phase?

1. Heat

2. Redness

3. Swelling

4. Pain and tenderness

5. Loss of function

Up to how long does the acute phase of healing take?

2 weeks

What are the three parts of the vascular response?

1. Vascular spasm

2. Chemical mediators

3. Extravasation (leakage of fluid)

What is the first part of the vascular spasm?

Vasoconstriction

How long does vasoconstriction last in vascular spasm (inflammatory response)?

About 5-10 minutes

What is the result of vasoconstriction in vascular spasm (inflammatory response)?

Local anemia

What mediates vasoconstriction in vascular spasm (inflammatory response)?

Norepinephrine

What is the second part of the vascular spasm?

Vasodilation

What is the result of vasodilation in vascular spasm (inflammatory response)?

Hyperemia (redness), increased blood flow, increased capillary permeability

What is the final part of the vascular spasm?

Slowing and stasis

What occurs in the slowing and stasis part in vascular spasm (inflammatory response)?

Increased concentration of red blood cells and leukocyte margination

What is leukocyte margination?

When the leukocytes move to the outside of the blood vessel to move through the tissue

What are the components of the vascular spasm in the inflammatory response?

1. Vasoconstriction

2. Vasodilation

3. Slowing and stasis

How long does the initial blood and plasma effusion last in vascular spasm?

24-36 hours

What are the chemical mediators in the inflammatory response?

- Histamine

- Hageman factor (clotting factor XII)

- Bradykinin

- Prostaglandins (PGE1 and PGE2)

- Anaphylatoxins (C3a, C4a, C5a)

- Cytokines

What releases histamine?

Injured mast cells

What does histamine do in the inflammatory response?

Increase vasodilation, increase vascular permeability, attracts leukocytes (chemotaxis)

How long is histamine active for in the inflammatory response?

About 1 hour post-injury

What is the Hageman factor?

Clotting factor XII

What does Hageman factor activate?

Activate coagulation, plasma proteins (plasmin, kallikrein), and complement system

What are bradykinins?

Biologically active peptides derived from plasma

What do bradykinins do in the inflammatory response?

Increase vascular permeability

What are the prostaglandins involved in the inflammatory response?

PGE1 and PGE2

What do prostaglandins do in the inflammatory response?

Increase vascular permeability, sensitize pain receptors, responsible for the febrile state (fever)

What is a febrile state?

Fever

What is responsible for the febrile state?

Prostaglandins

What is affected by NSAIDs and corticosteroids in the inflammatory response?

Prostaglandins

What are the anaphylatoxins involved in the inflammatory response?

C3a, C4a, C5a

What do anaphylatoxins do in the inflammatory response?

Increase vascular permeability

What are the cytokines involved in the inflammatory response?

Chemokines and interleukin

What do cytokines do in the inflammatory response?

Regulate leukocyte traffic and attract leukocytes to actual site of inflammation

What are the polymorphonucleocyte leukocytes?

Neutrophils, basophils, and eosinophils

How long do neutrophils live?

About 7 hours (short-lived)

What are the first line defense against bacteria in the inflammation response?

Neutrophils

How do neutrophils "deal with" bacteria?

Phagocytosis (engulf and kill)

What are some characteristics of neutrophils?

Small, fast, numerous, short-lived

What is the role of basophils in the inflammatory response?

Release histamine

What is the role of eosinophils in the inflammatory response?

Some phagocytosis

What are the mononuclear cell leukocytes?

Monocytes

When are monocytes predominate post-injury?

First 24-48 hours

What do monocytes become?

Macrophages

What is the purpose of vascular permeability?

Allows for leukocyte migration to injured area across endothelial cell walls?

What is extravasation?

The process of leukocytes migrate to the injured area across endothelial cell walls

What are the steps of extravasation?

1. Margination

2. Pavementing

3. Diapedesis

4. Emigration

What is the margination step of extravasation?

Leukocyte going to the walls of the vessel

What is the pavementing step of extravasation?

Leukocyte sticking to the vessel

What is the diapedesis step of extravasation?

Leukocyte squeezing through the vessel

What is the emigration step of extravasation?

Leukocyte moving to the source of the injury

What is edema?

Accumulation of fluid outside of the vessels

What is transudate?

Thin, clear serum

What is exudate?

Cloudy, serum highly concentrated with protein, WBCs, lipids, cellular debris (ie., blister)

What is pus?

Supportive exudate; opaque exudate highly concentrated in leukocytes, tissue debris, microorganisms

What can pus result in?

Abscess

Are inflammation, edema, and swelling the same?

No;

- Inflammation is the response

- Edema is fluid accumulation

- Swelling is increased tissue volume

What is the second part of the inflammatory response?

Hemostatic response

What occurs in the hemostatic response?

Clot formation

What do platelets bind to?

Collagen

What does platelets release?

Fibrin and platelet-derived growth factor (PDGF)

What does fibrin do?

Stimulates clotting process

What does platelet-derived growth factor do?

Stimulates cell growth and division

What do damaged cells release?

Thromboplastin

What causes the cessation of bleeding?

Temporary plug of fibrin lattice

What provides the tensile strength in the clot formation?

Temporary plug of fibrin lattice

When does clot formation begin?

Around 12 hours

When does clot formation complete?

By 48 hours

What is the third response of the inflammation response?

Cellular response

What generally occurs in the cellular response?

Phagocytosis

What is the purpose of phagocytosis?

Removal of phathogens and cell debris

What cells phagocytize?

Neutrophils and macrophages

When are neutrophils most active?

During first 24 hours

When are macrophages most active?

24-48 hours post-injury

What is the most important cell in the inflammatory process?

Macrophages

What enzyme do macrophages release?

Collagenase

What do macrophages attract?

Fibroblasts

What do macrophages release?

Collagenase, chemotactic factors, and substances to kill microorganisms