Chapter 1617: Immune system

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Chapter 16/17 Immune system
Lecture Chapter 16 Nonspecific defenses First
line of defense Formed elements Second line of
defense Complement system Chapter 17 Specific
defenses Antibodies Humoral response Cellular
response Continue APO-4
Lab SSE Unknowns
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Immunity terminology
Susceptibility- Lack of resistance to a
disease Resistance/ immunity- Ability to ward
off disease Innate (nonspecific) immunity-
Resistance to all microbes present from birth
(can be species specific) Adaptive (specific)
resistance- Resistance to a specific pathogen
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Host defense systems
Figure 16.1 - Overview (1 of 3)
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First lines of defense (Table 16.3)
Figure 16.3
Figure 16.2
Figure 16.4 (2 of 3)
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First line of defense- skin

• Physical factors
• Dermis and epidermis
• Lots of keratin

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First line of defense- skin

• Physical factors
• Dermis and epidermis
• Lots of keratin
• Chemical factors
• Sebum (includes fungistatic and
• bacteriostatic fatty acids)
• Low pH
• High salt
• Dry conditions, low temperature
• Lysozymes

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First line of defense- skin

• Physical factors
• Dermis and epidermis
• Lots of keratin
• Chemical factors
• Sebum (includes fungistatic and
• bacteriostatic fatty acids)
• Low pH
• High salt
• Dry conditions, low temperature
• Lysozymes
• - Normal microbiota

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First line of defense- mucosal surfaces

• Physical factors
• Mucous production
• Cilia
• Hairs

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First line of defense- mucosal surfaces

• Physical factors
• Mucous production
• Cilia
• Hairs
• Chemical factors
• Lysozymes
• Lactoferrin
• Defensin
• Normal microbiota

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First line of defense- lacrimal apparatus

• Physical factors
• Tears
• Chemical factors
• Lysozyme
• IgA

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Second line of defense- formed elements
Table 16.1 (2 of 3)
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Second line of defense- formed elements
Table 16.1 (3 of 3)
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SEM of formed elements
Bruce Wetzel (photographer). Harry Schaefer
(photographer) National Cancer Institute
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Complete blood count (CBC)
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Phagocytosis
Figure 16.7 - Overview
Figure 16.6
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Microbial evasion of phagocytosis
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Systemic inflammation or fever

• Usually set at 37 C
• Some chemical signals set it higher
• Cytokine interleukin-1
• Cytokine alpha-tumor necrosis factor
• Prostoglandins reset hypothalamic thermostat

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Localized inflammation

• Chemicals released
• Histamine
• Kinins
• Prostaglandins
• Leukotrienes
• Vasodilation
• 3. Increased permeability
• 4. Blood clot formation
• Abscess
• Tissue repair

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Inflammation- chemical signals
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Inflammation
MORE DETAIL Vasodilation/ increased Permeability
- Margination WBCs - Emigration
WBCs Activation of acute- phase proteins -
Cytokines - Kinins - Complement proteins -
(Interferons)
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Complement system
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3 complement activation systems
Alternative
Classical
Lectin
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Pit stop
People with Rhinovirus infections of the nose
and throat have an 80-fold increase in kinins and
no increase in histamine. What do you expect
for Rhinovirus symptoms? What disease is caused
by Rhinovirus?