Chemicals Released by Damaged Cells Histamine Vasodilation, increased permeability of blood vessels Kinins Prostaglandins Intensity histamine and kinin effect Leukotrienes Increased permeability of blood vessels, phagocytic attachment

Inflammation Figure 16.8a–b

Inflammation Figure 16.8c–d

Fever: Abnormally High Body Temperature Hypothalamus normally set at 37°C. Gram-negative endotoxin cause phagocytes to release interleukin–1 (IL–1). Hypothalamus releases prostaglandins that reset the hypothalamus to a high temperature. Body increases rate of metabolism and shivering which raise temperature. When IL–1 is eliminated, body temperature falls (crisis).

Fever Advantages Disadvantages Increase transferrins Increase IL–1 activity Disadvantages Tachycardia Acidosis Dehydration

The Complement System Serum proteins activated in a cascade. Figure 16.9

Effects of Complement Activation Opsonization or immune adherence: Enhanced phagocytosis. Membrane attack complex: Cytolysis. Attract phagocytes. Figure 16.10

Effects of Complement Activation Figure 16.11

Classical Pathway Figure 16.12

Alternative Pathway Figure 16.13

Lectin Pathway Figure 16.14

Some Bacteria Evade Complement Capsules prevent C activation. Surface lipid-carbohydrates prevent MAC formation. Enzymatic digestion of C5a.

Interferons (IFNs) Alpha IFN and Beta IFN: Cause cells to produce antiviral proteins that inhibit viral replication. Gamma IFN: Causes neutrophils and macrophages to phagocytize bacteria.

Interferons (IFNs) Figure 16.15

Innate Immunity Transferrins Antimicrobial peptides Bind serum iron Lyse bacterial cells