Acute Inflammation: Stage 1 Vascular Permeability

Summary

• Histamine and Bradykinin cause vasodilation and permeability of blood vessels, leading to fluid, WBCs, and platelets flooding to the site of injury.

• Capillary permeability allows WBCs in the fluid from capillaries to consume foreign material through phagocytosis.

Main Themes and Motifs

• Vasodilation and permeability of blood vessels

• Phagocytosis by WBCs

Acute Inflammation: Stage 2 Cellular Chemotaxis

Summary

• Microbial agents, endothelial cells, and WBCs attract platelets and other WBCs to the site of injury.

• Margination forms a protective wall, and cytokine/interleukin is released, leading to leukocytosis.

Main Themes and Motifs

• Chemotaxis of WBCs

• Leukocytosis

Cytokines and Interleukins

Summary

• Cytokines are proteins from glial cells in the nervous system that act as signaling molecules, stimulating the liver to release CRP and increasing or decreasing reactions.

• Interleukins are a subset of cytokines that moderate cellular behavior and act as messenger molecules between immune cells.

Main Themes and Motifs

• Signaling molecules

• Moderation of cellular behavior

Neutrophils and Monocytes

Summary

• Neutrophils are the first line of defense, with a lifespan of 10 hours to 2 days, and start phagocytosis.

• Monocytes are the largest WBCs that differentiate into macrophages and take over phagocytosis, indicating a more chronic process.

Main Themes and Motifs

• Phagocytosis

• Chronic inflammation

Acute Inflammation: Stage 3 Systemic Response

Summary

• Prostaglandins, leukotrienes, TNF alpha, interleukins, and pyrogens control the systemic response.

• Prostaglandins are responsible for pain, leukotrienes help produce mucus, TNF alpha comes from monocytes, interleukins play a role in cell growth, and pyrogens act on the hypothalamus and activate heat, leading to fevers.

Main Themes and Motifs

• Systemic response

Mind Map: Acute Inflammation

Central Idea

Acute inflammation is a process that occurs in response to injury or infection.

Main Branches

1. Stage 1 Vascular Permeability

2. Stage 2 Cellular Chemotaxis

3. Stage 3 Systemic Response

4. Tissue Healing

Stage 1 Vascular Permeability

• Histamine (Mast Cells) + Bradykinin = vasodilation and permeability of blood vessels

• Fluids, WBCs, and platelets flood to the site of injury

• Capillary permeability

• WBC in the fluid that comes from capillaries consumes foreign material = phagocytosis

Stage 2 Cellular Chemotaxis

• Microbial agents, endothelial cells, and WBCs attract platelets and other WBCs to the site of injury

• Margination protective wall is formed

• Cytokine/Interleukin gets released

• Leukocytosis occurs

• Neutrophils: first line defense, start phagocytosis

• Monocytes: largest WBC, differentiate into macrophages, take over phagocytosis, indicates the more chronic process

Stage 3 Systemic Response

• Controlled by prostaglandins, leukotrienes, TNF alpha, interleukins, pyrogens

• Prostaglandins: responsible for pain

• Leukotrienes: helps produce mucus

• TNF alpha: come from monocytes

• Interleukins: play a role in cell growth

• Pyrogens: act on hypothalamus and activate heat- leading to fevers

Tissue Healing

• Stage 1: Inflammation occurs

• Stage 2: Reconstructive/proliferation occurs

  • Fibroblasts synthesize collagen to make a foundation for scar tissue (granulation tissue)

  • Granulation tissue secretes cytokines and growth factors

  • Epithelial cells help make a new surface

• Stage 3: Maturation/remodeling

  • Fibroblast/myofibroblasts refine scar tissue

• 3 stages of tissue healing: primary intention, secondary intention, tertiary intention

• Healed primary intention scar ends up as a hairline scar

• Healed secondary intention scar: epithelium grows over