Chapter 21: The Lymphatic and Immune System Powerpoint Outline Flashcards
agents capable of producing disease
includes viruses, bacteria, and fungi
Pathogens
There are ______ lines of defenses against pathogens
three
First line of defense includes:
skin and mucous membranes
Second line of defense includes:
several nonspecific defense mechanisms
Third line of defense includes:
the adaptive immune system. (defeats a pathogen, and leaves the body with a “memory” of it so it can defeat it faster in the future)
- guard equally against a broad range of pathogens
- they lack capacity to remember pathogens
- three kinds (protective cells, protective proteins, & protective processes)
Nonspecific Defenses
Nonspecific Resistance
- body must develop separate immunity to each pathogen
- body adapts to a pathogen and wards it off more easily upon future exposure
Specific or Adaptive Immunity
Nonspecific Resistance
- toughness or keratin
- too dry and nutrient poor for microbial growth
- produces dermicidin, defensins, and cathelicidins that kill microbes
Skin
(External barrier)
(1st Line of Defense)
- mucus physically traps microbes
- lysozyme: enzyme destroys bacterial cell walls
- four systems = reproductive, digestive, respiratory, urinary
Mucous membranes
(External barrier)
(1st Line of Defense)
- lower pH inhibits bacterial and fungal growth
- sweat, sebum, vagina, stomach
“Acid mantle”
1st Line of Defense
- penetration of microbes slowed by moving them out of susceptible area
- urination, salivation, lacrimation, mucus-ciliary escalator
“Fluid flow”
1st Line of Defense
What consists of:
- protective cells = leukocytes, macrophages, and natural killers (NK) cells
- protective proteins = interferons and complement proteins
- protective responses = fever and inflammation
2nd Line of Defense
Name this WBC:
- kill bacteria using phagocytosis
- can kill by producing a respiratory burst
- lysosomes degranulate releasing bactericidal chemicals
- creates a killing zone around this WBC
Neutrophils
Name this WBC:
- guard against parasites, allergens, (allergy-causing agents), and other pathogens
- kills tapeworms and roundworms by producing superoxide, hydrogen peroxide, and toxic proteins
Eosinphils
Name this WBC:
- secrete histamine: promotes inflammation
- secretes heparin: inhibits clot formation
- Mast cells also secrete these substances; similar to this WBC but found in other connective tissue
Basophils
Name this WBC:
-leaves blood and transform into macrophages
Monocytes
- wandering macrophages actively seek pathogens
- Fixed macrophages phagocytize only pathogens that come to them
What system is this?
Macrophage System
- type of lymphocyte that is not a B-cell or T-cell
- continually patrol body looking for pathogens and diseased host cells
- attack and destroy bacteria, transplanted cells, cells infected with viruses, and cancer cells
Natural Killer (NK) Cells
- proteins that inhibit microbial reproduction and provide short-term, nonspecific resistance to pathogenic bacteria and viruses
Protective Proteins
2nd Line of Defense
List the two families of antimicrobial proteins
- interferons
- complement system
- secreted by certain cells infected by viruses
- of no benefit to the cell that secretes them
- alerts neighboring cells and protects them
Interferons
What happens to the original cell that secreted the interferon?
It dies; it tried to protect everyone around it
- group of 30 or more proteins
* four methods of pathogen destruction when activated
Complement System
Inflammation, Immune Clearance, Phagocytosis, and Cytolysis are mechanisms of _________ _________
Complement System