7.1 Inflammation and Tissue Repair

Question 1

Innate Immunity

Answer 1

• Series of barriers that keep foreign invaders out.
• Intact skin, mucous membranes, cilia in respiratory tract, saliva, sweat
• Second line of defense is the inflammatory system.
• Always general and non specific

Question 2

Inflammatory Response

Answer 2

• Bodies innate defenses
• Activation occurs at site of injury from mechanical damage, ischemia, nutrient deprivation, infection, chemical agents, temperature extremes etc.
• Relies on activity of both cellular and chemical components.
• Rapid, nonspecific, response to foreign tissue damage.
• Can be acute, subacute or chronic

Question 3

Acute Inflammation

Answer 3

• Healing occurs in 2-3 weeks.
• Usually does not leave damage
• Neutrophils are predominant

Question 4

Subacute Inflammation

Answer 4

• Subacute inflammation has same features of acute but last longer

Question 5

Chronic Inflammation

Answer 5

• Lasts for weeks, months, years
• Agent persists or repeatedly injures tissue
• Lymphocytes and macrophages are the predominant cell type
• (Rheumatoid Arthritis and Tuberculosis)
• Inflammation is always present with infection but infection is not always present with inflammation

Question 6

Inflammation (Cont)

Answer 6

• Infection is invasion of tissue cells by microorganisms such as bacteria, fungi, and viruses
• Inflammation can also be caused by nonliving agents such as heat, radiation, trauma, and allergens

Question 7

Goals of inflammation

Answer 7

• Limit and control inflammatory process with plasma protein systems and cells
• Prevent infection and further damage by using fluid flux, plasma protein system and cells.
• Interact with adaptive immune system to elicit specific response using macrophages and lymphocytes

Question 8

Acute Inflammation

Answer 8

• Immediate response that takes place before adaptive immunity is established. (Not immediately fatal)
• Remove injurious agent, limit the extent of tissue damage, stimulate and enhance the adaptive immune response.
• Self limiting - only until threat to host is eliminated
• Healing lasts 8-10 days

Question 9

Cardinal Signs of Acute Inflammation

Answer 9

Redness - Hyperaemia 
Warmth - Hyperaemia
Swelling - Increased Permeability
Pain - Low pH
Loss of Function - Pain and swelling

Question 10

Components of Inflammatory Response

Answer 10

• Vascular Response
• Activation of plasma protein system
• Activation of a variety of cells

Question 11

Vascular Response

Answer 11

• Involves arterioles, capillaries, venules, microcirculation.
• Increased vascular permeability allows outpour of exudate (protein rich fluid) into extravascular spaces

Question 12

Vascular Response

Answer 12

• Loss of fluid leads to increased RBC, WBC, platelets and clotting factors at site with stagnation of blood flow and clotting at injury site.
• This eliminates spread of infectious agents
• Edema due to loss of plasma protein to interstitial fluid.
• Fluid shifts from intravascular to interstitial and causes pain and decreased function.

Question 13

Vascular Response (cont)

Answer 13

• ## Vasodilation and chemical mediators cause endothelial cell retraction increasing capillary permeability.