Download Immune System: Non

IMMUNE SYSTEM: NON-SPECIFIC
DEFENSE
Pages 957-960
FUNCTION
•Fights pathogens to prevent
infections and disease
•Works with the lymphatic
system (collects fluid and
returns it to the blood)
STRUCTURES
•Bone marrow: produces blood cells
•Lymphocytes: white blood cells (WBC)
•Lymph nodes: stores WBC
•Thymus: matures WBC
•Spleen: contains WBC that clean out
pathogens as blood filters through
INITIATING THE IMMUNE SYSTEM
•Antigen: any substance that the immune system
responds to
•Allergens: Cause allergies (pollen, dust mites, mold, etc.)
INITIATING THE IMMUNE SYSTEM
•Antigens continued
•Pathogens: cause disease
•Viruses: protein shell containing DNA or RNA
•Bacteria
•Fungi (spores)
•Parasites
•Toxins (snake bites etc)
NONSPECIFIC DEFENSE
•Protects body against any pathogen, regardless of
the pathogen’s identity
FIRST LINES OF DEFENSE
•Skin
•Blocks entry
•Sweat & oil are toxic to many pathogens
•Mucous membranes
•Mucous: traps pathogens
FIRST LINES OF DEFENSE
•Cilia: moves pathogens out of body
•Stomach acids: destroys pathogens
SECOND LINE OF DEFENSE: NON-SPECIFIC
RESPONSE
Inflammatory Response
SECOND LINE OF DEFENSE: NON-SPECIFIC
RESPONSE
•Inflammatory Response
1. Injured cells release a chemical signal called histamine to
increase blood flow to area
2. Platelets cause clotting trapping pathogens
3. Area swells, becomes warm, and macrophages/phagocyte
(WBC) move in and engulf bacteria
SECOND LINE OF DEFENSE: NON-SPECIFIC
RESPONSE
•Interferons: enzymes that stop virus protein
production
•Fever: slow growth of bacteria and increase activity
of WBC
•Should a fever always be treated? Why or why
not?
SECOND LINE OF DEFENSE: NON-SPECIFIC
RESPONSE
•White blood cells: there are many types, some act
in a non-specific way, these WBC are called
Phagocytes
SECOND LINE OF DEFENSE: NON-SPECIFIC
RESPONSE
•Types of phagocytes
Neutrophils: Ingest pathogens
Macrophage: Engulf pathogens & other cell debris
Natural Killer Cells: Burst pathogen infected cells