Host defenses: Immunity

1
Ch. 10 Innate Host Defense Mechanisms

• Host defenses Immunity
• First-line defense
• Second-line defense
• Cells of the immune system
• Phagocytosis
• Inflammation Fever

2
Host Defense

• Innate Immunity
• First-line defense
• Second-line defense
• Aquired Immunity
• Third-line defense
• Discussed in Ch. 11 12

3
First line defense

• Anatomical barriers
• Antimicrobial substances
• Normal flora

4
Anatomical barriers
5
Epithelial barriers
6
Antimicrobial substances
7
Normal flora
8
Second-line defense

• White Blood Cells
• Granulocytes
• Mononuclear Phagocytes
• Lymphocytes
• Phagocytosis
• Other Blood Components
• Lymphatic System

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10
Table 15.2
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12
Mononuclear phagocytes
Figure 15.5
13
Phagocytosis

• Neutrophils
• Macrophages
• Produce cytokines
• Interact with T helper cells activated
  macrophages
• Help form granulomas
• Process of phagocytosis

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Process of phagocytosis
Figure 15.9
15
Other Blood Components

• Red Blood Cells, Platelets, Plasma
• Important role in inflammatory response
• Major function is blood clotting
• Serum
• Clear yellowish fluid that contains proteins
• Albumin
• Globulin gamma portion contains antibodies
• Complement system
• Classical pathway
• Alternate pathway
• Interferons glycoproteins

16
Figure 15.7
17
Interferons
Figure 15.11
18
Lymphatic System

• Lymphatic vessels
• 1º lymphoid organs
• Thymus
• Bone marrow
• 2º lymphoid organs
• Lymph nodes
• Adenoids
• Tonsils
• Spleen
• Appendix
• SALT
• MALT

19
Inflammation

• Initiation
• Inflammatory process
• Outcomes of inflammation

20
Initiation

• Release of chemicals
• Histamine, serotnin, kinins, and prostaglandins
• Increase in the permeability of surrounding blood
  vessels
• Complement cascade
• Tissue damage

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Inflammation process
Figure 15.10
22
Inflammation process
Figure 15.10
23
Outcomes of inflammation

• Damage to surrounding tissue
• Release of bacterial endotoxins
• Eliminate invading pathogen
• Fibroblast formation

24
Fever

• Physiological response to infections
• Pyrogens
• Endogenous fever-inducing cytokines
• Exogenous bacterial endotoxins
• Hypothalamus controls temperature
• High temperature inhibits pathogen growth