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
Stimulates mast cells and basophils to secrete histamine
Inflammation
- binds with antigen-antibody (Ag-Ab) complexes to RBCs
- when these RBCs circulate through liver and spleen, macrophages strip off and destroy the Ag-Ab complexes leaving RBCs unharmed
- principal means of clearing foreign antigens from the bloodstream
Immune Clearance
*assists phagocytes by opsonization (coating microbial cells)
Phagocytosis
- forms a membrane attack complex
- forms a hole in the target cell
- electrolytes leak out, water flows in rapidly, cell ruptures
Cytolysis
Protective responses:
2nd Line of Defense
- fever
- inflammation
- both slow the spread of infections
- Hypothalamus elevates body temperature
- Response to pyrogens (exogenous or endogenous)
Fever
Moderate fever is helpful:
- promotes interferon activity
- elevates metabolic rate and accelerates tissue repair
- inhibits reproduction of bacteria and viruses
- local response to tissue injury, including trauma and infection
- general purposes of inflammation; limits spread of pathogens then destroys them, removes debris from damaged tissue, initiates tissue repair
Inflammation
List the four cardinal signs of inflammation
- redness, swelling, heat, and pain
How many steps does inflammation have?
5
Release of inflammatory chemicals such as cytokines (ex. histamine)
Which step of inflammation is this?
Step 1
Vascular Changes: the chemicals cause vasodilation which increases blood flow to the area - produces redness & warmth; the chemicals will increase permeability of the capillaries, which increases leakage into the interstitial areas - produces swelling (edema) & pain - moves material into lymphatic vessels
Which step of inflammation is this?
Step 2
Clotting factors (now in the interstitial area) form clots to wall off the area. Prevents spread of bacteria. Heparin prevents clotting directly at the injury site.
Which step of inflammation is this?
Step 3
Attraction of neutrophils, then macrophages to the area (phagocyte mobilization)
Which step of inflammation is this?
Step 4
Tissue Repair
Which step of inflammation is this?
Step 5
How many steps does phagocyte mobilization?
4
Leukocytosis: release of neutrophils from bone marrow in response to leukocytosis-inducing factors from injured cells
Which step of phagocyte mobilization is this?
Step 1
Margination: neutrophils cling to walls of capillaries in inflamed area
Which step of phagocyte mobilization is this?
Step 2
Diapedesis of neutrophils
Which step of phagocyte mobilization is this?
Step 3
Chemotaxis: inflammatory chemicals promote positive chemotaxis of neutrophils
Which step of phagocyte mobilization is this?
Step 4