Download File - Pomp

The Immune System
• Chapter 43 ~
PCA:
• List the organs involved in the immune sytem:
Lines of Defense
Nonspecific Defense Mechanisms……
Innate Immunity
• First defense
– Skin
– Mucous membranes
– Secretions- skin and mucous membranes
“You men come with me, the rest
of you run with mucus…”
• Mucous membranes
– Line digestive, respiratory and genital tracts
– Low pH
– lysozymes
Innate Immunity:
• Specialized phagocytic white blood cells
• Antimicrobial proteins
• Inflammatory response
Innate Immunity: 5 types of Leukocytes
• Neutrophils
• 60-70% WBCs; engulf and
destroy microbes at infected
tissue
Short lived
• Monocytes
• 5% WBCs; develop into….
– Macrophages
1)phagocytosis
– 2)lysosomal enzymes destroy
microbes
• Dendritic cells:
• Stimulate development of
the acquired immune system
Innate Immunity: 5 types of Leukocytes
• Eosinophils
• 1.5% WBCs; destroy large
parasitic invaders
• Enzymatic action- no
phagocytosis
• Natural killer (NK) cells
• destroy virus-infected body
cells & abnormal cells
• apoptosis
Antimicrobial Proteins:
1. Complement system- group of 30 proteins
 Once activated can cause invading cells to
lyse – burst
– Compliment the ability of antibodies and
phagocytes
2. Interferons (α, β and γ)
 Immune response to viruses
 Activates macrophages
The Inflammatory Response
•
Tissue injury; release of chemical signals~
• histamine (basophils/mast cells):
• prostaglandins: increases blood flow & vessel
permeability
• Dilation and increased permeability of capillary~
• chemokines: secreted by blood vessel endothelial cells
mediates phagocytotic migration of WBCs
Lymphatic System:
• Consists of:
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Lymphatic vessels
Lymph nodes
Adenoids
Tonsils
Appendix
Spleen
Peyer’s patches
Lymphatic System:
• Function:
– Traps foreign molecules and various substances
– Returns lost fluids back to circulatory system
Lymphatic System:
• Connection with Immune System:
– Foreign molecules and invaders encounter
macrophages, dendritic cells, and lymphocytes
which take various defense actions to activate and
immune response and destroy pathogens.