Micro Test 3 Epidemiology, Flu, and HIV (Part 4)
Define innate immunity.
resistance due to physiological processes of humans that are incompatible with those of the pathogen
Give two examples of innate immunity.
correct chemical receptors are not present on human cells
temp and pH may not be compatible with those necessary for pathogen survival
What happens if a subject has no innate resistance?
Results in disease
What does the first line of defense do?
prevents pathogens from entering the body
What are nonspecific first line of defenses?
physical and chemical
includes skin and mucous membranes of the respiratory, digestive, urinary and reproductive systems.
Few pathogens can penetrate these layers
shedding of dead skin cells removes attached microorganisms
contains epidermal dendritic cells
What skin layer is this?
gives skin strength and pliability to resist abrasions
what skin layer is this?
How does perspiration secreted by sweat glands help with immunity?
salt can inhibit cell growth by drawing out water
antimicrobial peptides (dermicidins)
Lysozomes ( destroy cell wall of bacteria)
How does sebum secreted by oil glands help with immunity?
keeps skin pliable (less likely to break or tear)
lowers pH of skin
How do mucous membranes help with immunity?
line all body cavities open to the outside environment
What two cells in the epidermis deal with mucous?
Goblet cells - secrete mucous
ciliated cells - propel mucous
why is it a good thing that the cells of the epidermis are tightly packed?
prevents entry of pathogens
Normal microbiota help protect the body by competing with potential pathogens. How?
Secrete antimicrobial substance (lacrimal glands)
Consumption of nutrients
help to stimulate second line of defense
provide vitamins to host
When pathogens succeed in penetrating the first line of defense what kicks in?
the second line of defense
the second line of defense is composed of what?
This is composed of cells and portions of cells within a fluid called plasma.
This is mostly water containing electrolytes, dissolved gases, nutrients, and proteins,
What is produced when the clotting factors and plasma proteins are removed from plasma?
What are the three formed elements of blood?
What do erythrocytes do?
carry oxygen and carbon dioxide
What do platelets do?
involved in clotting
What do leukocytes do?
WBC involved in defending the body
(Granulocytes and Agranulocytes)
What are granulocytes?
WBC that contain large granules that stain different colors based on the dye used.
What are the three granulocytes and what stains are used on them?
Basophils - basic dye methalyene blue
Eosinophils - acidic dye eosin
Neutrophils - stain lilac with a mixture of acidic and basic dyes
What two granulocytes phagocytize and are able to diapedesis (more between capillary walls)?
eosinophils and neutrophils
This granulocyte is 0.5-1% and releases histamine to mediate inflammation.
This granulocyte is 2-4%, is phagocytic, diapedisis, increased during allergy/parasitic worm infection.
This granulocyte makes up 60-70%, is phagocytic, diapedesis, and is increased during bacterial infections to help mediate inflammation.
What are the two types of agranulocytes?
lymphocytes and monocytes
What kind of agranulocyte is most involved in adaptive immunity?
What kind of agranulocyte leaves the blood and matures into macrophages?
This agranulocyte makes up 20-25% and is mostly involved in specific immunity?
This kind of agranulocyte makes up 3-8% and matures into macrophages.
Fixed macrophages include what?
Where can you find wandering macrophages?
through out the body
In a mononuclear phagocytic system, all macrophages, plus monocytes are attached to what?
This test of WBC can signal signs of disease.
differential white blood cell count
Increased eosinophils can indicate what?
allergic reactions or parasitic worm infection
Increased leukocytes and neutrophils can indicate what?
Increased in lymphocytes can indicate what?
What are the mechanisms of the second line of defense?
extracellular killing by leukocytes
nonspecific chemical defense
What are the 5 stages of phagocytosis?
1. chemotaxis of phagocyte to microbes
3. ingestion of microbes by phagocyte
4. killing of microbes by chemicals and other enzymes
How do eosinophils attack parasitic worms?
secreting toxins that weaken or kill them
How do natural killer lymphocytes (NK cells) work?
by secreting toxins onto the surface of virally infected and cancerous cells
How do natural killer lymphocytes (NK cells) differentiate infected cells from normal body cells?
normal body cells have membranes similar to the NK cells
How do neutrophils defend against invaders?
produce chemicals that kill nearby invaders
generate extracellular fibers that bind to and kill bacteria
what is a complement system?
set of serum proteins
What happens in complement activation?
the lysis of the foreign cell
How are complement systems activated?
Classical pathway - Ag-Ab activate
Alternate pathway - pathogens and/or products activate
The alternate complement pathway is also called the what?
in the alternate complement pathway, activation occurs __________ of antibodies.
Why is the alternate complement pathway useful in early stages of infection?
because the antibodies have not yet been made
For alternate complement pathway activation to occur, what does it require?
the interaction of three proteins (Properdin Factors B, D, and P) with bacterial or fungal endotoxins or LPS
These are protein molecules released by the host cells and nonspecifically inhibit the spread of viral infections.
Interferons are most effective on what kind of virus?
What are the three classes of interferons?
Alpha & Beta - early stages of infection
Gamma - later stages, activates macrophages
These are small peptides that punch holes in cytoplasmic membranes and interfere with internal signaling and other metabolic processes.
What can increase defensin production?
This is a nonspecific response to tissue damage resulting from various causes.
what is used to characterize inflammation?
what are the two types of inflammation?
chronic and acute
Describe acute inflammation.
important second line of defense
dilation and increased permeability of the blood vessels
migration of phagocytes
Describe chronic inflammation
can cause tissue damage
What is a fever?
body temp over 37 degrees celcious
How is a fever achieved?
pyrogens trigger the hypothalamus to increase the body's core temp
What kinds of pyrogens can cause a fever?
cyctoplasmic contents of lysed cells
How does IL-1 increase the body temperature?
causes the hypothalamus to secrete prostaglandidn which resets the hypothalamic "thermostat"
This initiates muscle contractions, increased metabolic activity, and constriction of blood vessels.
What happens to the bodys temperature if IL-1 production decreases?
What effect does a fever have on interferons?
Having a fever may enhance what things?
cells of specific immunity
Define adaptive immunity
the bodies ability to recognize and defend itself against distinct invaders and their products
What cells are involved in adaptive immunity?
T and B cells
molecules that trigger a specific immune response
Give some examples of antigens.
components of bacterial cell walls such as capsules, pili, and flagella
proteins of viruses, fungi, and protozoa
How do antigens enter the body?
breaks or tears in skin and mucous membranes
direct injection as with a bite or needle
through organ transplant and skin grafts
Where do B lymphocytes come from?
arise and mature in red bone marrow
Where are B lymphocytes primarily found?
in spleen, lymph nodes, and MALT
What is the major function of B lymphocytes?
secretion of antibodies
What is another name for an antibody?
What is an antibody?
soluble proteins that bind antigens
Where do antibodies come from?
Secreted by B cells that are actively fighting exogenous antigens
What are the 5 classes of antibodies?
The type of antibody needed to fight an invader depends on what?
type of foreign antigen
portal of entry
antibody function needed
the function of this antibody is agglutination and neutralization.
the function of this antibody is unknown.
the function of this antibody is to trigger the release of histamines from basophils and mast cells.
the function of this antibody is complement activation, agglutination, osponization and neutralization and it crosses the placenta to protect the fetus.
The function of this antibody is to complement activation, agglutination, and neutralization.
These are cells produced by B cell proliferation that do no secrete antibodies.
Memory B cells
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