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35 Cards in this Set

  • Front
  • Back
What is the first line of defense?
Mechanical and chemical barriers to infection; The same response no matter what the pathogen is.
List the mechanical and chemical barriers to infection.
-Intact skin and the waterproof protein keratin provide resistance (sebum)to microbial infection.
-Lacrimal apparatus protects the eyes from irritating substances and microorganisms through tears (lysozymes).
-Saliva washes microorganisms from teeth and gums.
-The mucous ciliary escalator moves mucus up and out of the lower respiratory tract.
-The flow of urine moves microorganisms out of the urinary tract and helps prevent UTIs.
What is the second line of defense?
Responses specific for the pathogen.
List the 2nd line of defense responses to infection.
-Complement is activated
What are the various types of leukocytes used in phagocytosis.
Describe the function of the neutrophil.
Neutrophil (granulocytes)-
1st to show up for damaged tissue, and has the most prominent activity.
Describe the function of the Eosinphil.
Production of toxic proteins against worms/parasites.
Describe the function of the Monocyte.
Monocyte (agranulocytes)-
2nd to arrive on the scene; monocytes are found in the blood, however macrophages are mature monocytes that are found within the tissues.
Describe the function of the Basophils.
Basophils- when tissue becomes damaged, mast cells in tissues crawl out and secret histamines in an immune response to inflammation.
Describe the process of phagocytosis.
1. Chemostaxis- is the process by which phagocyts are attracted to microorganisms.

2. Adherence- the phagocyte then adheres/attaches to the microbial cells.

3. Ingestion- by endocytosis.

4. Digestion- many phagocytized microorganisms are killed by lysosomal enzymes and oxidizing agents.
List the locations of fixed macrophages.
Fixed macrophages live in the alveoli sacs of the lungs, liver, spleen (filters the blood), and lymph nodes (filters lymph and it enters back into subclavian vein to the heart) and brain. (microglia)
Describe ways that pathogens avoid phagocytosis.
-Capsules- no attachment b/c capsules are too slippery.

-Mycobacterium- has the waxy cell wall, which resists digestion.

-Listeria monocytogenes(underlined)- enters the cytoplasm and lysis the vesicle.
What is inflammation?
Inflammation is the body's response to tissue damage.
-To destroy the injurious agent, if possible, and to remove it and its by-products from the body.
-If destruction not possible, to confine off the injurious agent by forming an abscess.
-To try to repair or replace tissues damaged when supporting or functioning tissue produces new cells.
Describe the stages of inflammation.
The stages of inflammation are heat, pain, redness,swelling, and sometimes function.

-Heat occurs b/c heat speeds things up, and there is more blood in the area.

-Pain is body's response to alert us that something is wrong.

-Redness occurs b/c of more blood pooling to the damaged area.

-Swelling occurs b/c of leaking of fluid into the surrounding tissue.

-Sometimes loss of function.
What chemicals trigger inflammation?
-The release of histamine, kinins, and prostaglandins cause vasodilation and increased permeability of blood vessels.

-After injury, mast cells secret histamines, which attracts phagocytes. The 1st to show up are the neutrophils. The 2nd to arrive are the macrophages, which do a much better job of cleaning up the area.
Describe the cause and effects of fever.
-Fever is a high body temperature produced in response to bacterial or viral infection. The normal body temperature is 37C, or 98.6F.

-Fever of/over 40C or 102F is serious and can become dangerous b/c of denaturing tissue in the brain.

-The hypothalamus is the body's thermostat; the hypothalamus resets the thermostat.

-The cause of fever is pyrogens/LPS

-A chill indicates a rising body temperature; sweating indicates that body's temperature is falling.

-Fever slows down the pathogen; the higher temperature speeds up the Immune system and may help body tissues to repair themselves more quickly.
Describe the ways complement is activated.
1. Antibodies attach to cell surfaces.

2. Chemicals on surface of cells that are a part of the cell.
What is the activation of complement?
-The complement system consists of a group of serum proteins that activate on another to destroy the invading microorganism.

-Complement proteins are activated in a cascade.

-C3 activation cana result in cell lysis, inflammation, and opsonization.

-Complement is activated via the classical pathway-- antibodies attach to cell surfaces.

-Or by the alternative pathway-- Chemicals on surface of cells that are a part of the cell.

-Complement is deactivated by host-regulatory proteins.

-Complement deficiencies can result in an increased susceptibility to disease.

-Some bacteria evade destruction by complement by means of capsules, surface lip-carbohydrate complexes, and enzymatic destruction of C5a.
The branch of immunology that studies blood serum and antigen-antibody rxns in vitro.
What is serum?
Serum is the liquid remaining after blood plasma is cleared.

Plasma minus the clotting factors equal serum.
Blood is composed of:
RBCs =45%; hematocrit is full of iron which is dense and centrifuges to the bottom.


Describe the 3 results of complement activation that prevent infection.
1. Inflammation- mast cells that produce histamines.

2. Membrane Attack Complex (MAC)- complement proteins C5-C9, which together make lesions in cell membranes that lead to cell death.

3. Opsinization- like a red flag; the enhancement of phagocytosis by coating microorganism with certain serum proteins.
Explain how interferons limit virus infections.
-First, virus is infected.
-Interferons (IFNs) warn their neighbors
-Neighbors make antiviral proteins (AVPs) that stop multiplication of the virus.
-IFNs are host-cell-specific, but not virus-specific.
Antiviral proteins
a protein made in response to interferon that blocks viral multiplication
swelling; collection of fluids
an enzyme capable of hydrolyzing bacterial cell walls
Membrane Attack Complex (MAC)
complement proteins C5-C9, which together make lesions in cell membranes that lead to cell death
like a red flag; the enhancement of phagocytosis by coating microorganism with certain serum proteins.
a substance typically produced by a bacterium, that produces fever.
the ability of the human body to ward off diseases.
The lack of resistance to an infectious disease
Nonspecific resistance
Host defenses that tend to protect the body from any kind of pathogen
How do fixed and wandering macrophages differ?
Phagocytic cells that migrate to the infected area are called wandering macrophages.

Fixed macrophages remain in certain tissues and organs.
Summarize the outcomes of complement activation.
Activation of complement can result in immune adherence and phagocytosis, local inflammation and cell lysis.
antibodies are proteins that attach to specific antigens and stimulate an immune response.