Term
| The 3 lines of Human Body Defense |
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Definition
Skin
Mucouse Membranes
Lacrimal apparatuses
Normal Microbiota
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Term
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Definition
| In many cases the chemical receptors of these pathogens require an attachement to a host cell that does not exsist in in the human body. |
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Term
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Definition
| Is the 1st 2 lines of defense because they are present at birth prior to contact with infectious agents or their products. Innate Imunnity is rapid and works agaisnt a wide variety of pathogens, including parasitic worms, protozoa, fungi, bacteria, and viruses. |
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Term
Physical and Chemical aspects of
SKIN |
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Definition
Physical aspects - the skin is composed of miltiple layers which are tightly packed cells. With deeper cells of the epidermis continually divide, pushing their daugther cells toward the surface.
Chemical aspects - substances that are nonspecifically defend against pthogens. Dermal cells secrete antimicrobial peptides and sweat glands secrete perspiration, which contains salt, antimicrobial peptides, and lysozyme. |
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Term
Locations of the
body's mucous membranes |
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Definition
| mucous membranes cover all body cavities that are open to the outside environment. They line the lumens of the respiratory, urinary, digestive, and reproductive tracts. |
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Term
How Mucous Membranes
protect Physically and Chemically |
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Definition
Physically - unlike surface epidermal cells, surface cells of mucous membranes are alive and play roles in the diffusion of nutrients and oxygen and in the elimination of wastes.
Chemically - mucous membranes produce chemicls that defend against pathogens. Nasal mucus contains lysozyme, which chemically destroys bacterial cell walls. |
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Term
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Definition
| normal microbiota plays a role in protecting the body by comepeting with potential pathogens in variety of ways, a situation called microbial antagonism . Microbiota stimulate the body's second line of defense. The resident microbiota of the intestines improve overall health by providing several vitamins, inclucing biotin and pantothenic acid(B5)- important in glucose metabolism. |
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Term
1st line of Defense Vs.
2nd line of Defense |
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Definition
1st line - the 1st barrier and fighter against foreign pathogens entering our body with barries such as our skin and mucous membrane
2nd line - comes to our bodies defense when pathogens make their way past the 1st line of defense. it acts against a wide variety of pathogens, from parasitic worms to viruses. does not have barriers instead its composed of cells |
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Term
Blood and
their functions |
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Definition
Plasma- involved in inflammation and in blood clotting, a denfense mechanism that reduces both blood loss and the risk of infection.
Leukocytes - the formed elements that are directly involved in defending the body against invaders. There are 5 types Basopils, Eosinophils, Neutrophils, Lymphocyte, and Monocytes.
When increase amount of white blood cells is a sign of disease. |
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Term
| Six stages of Phagocytosis |
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Definition
Chemotaxis
Adherence
Ingestion
Maturation
Killing
and Elimination
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Term
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Definition
Chemotaxis is the movement of a cell either towrad a chemical stimulus (postive Chemotaxis) or away from a chemical stimulus (negative Chemotaxis)
In the case of phagocytes, positive chemotaxis involves the use of pseudopodia to crawl toward microorganisms at the site of an infection
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Term
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Definition
| after arriving at the site of an infection, phagocytes attach to micrroorganisms through the binding of complementary chemicals such as glycoproteins found on the membranes of cells. |
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Term
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Definition
| after phagocytes adhere to pathogens, they extend pseudopodia to surround the microbe. The encompassed microbe is internalized as the pseudopodia fuse to form food vesicle called a Phagosome |
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Term
| Phagosome Maturation and Microbial Killing |
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Definition
a series of membraneous organelles within the phagocyte fuse with newly formed phagosomes to form digestive vesicles. one organelle, the lysosome adds digestive chemicals to the maturing phagosomes, now called Phagolysomes.
Most pathogens are dead within 30 mins, though some bacteria contain virulence factors that resist a lysosome's action. |
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Term
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Definition
| Digestion is not always complete and phagocytes eliminate remnants of microorganisms via exocytosis, a process that is essentially the reverse of ingestion. |
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Term
Nonphagocytic Killing
aspects |
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Definition
- Killing by Eosinophils
- Killing by Natural Killer Lymphocytes
- Killing by Neutrophiles
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Term
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Definition
| Eosinophils attack parasitic helminths (worms) by attaching to the worms surface, where they secrete extracellular protein toxins onto the surface of the parasite. They can also attack bateria, lipopolysaccides and gram-negative bacteria. |
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Term
| Killing by Natural Killer Lymphocytes |
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Definition
| NK cells are another type of defensive leukocyte of innate immunity that works by secreting toxins onto the suraces of virally infected cells and neoplasms. |
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Term
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Definition
Neutrophils do not always devour pathogens; they can destroy nearby microbial cells without phagocytosis. They do this is 2 different ways:
Enzymes in a neutrophil's cytoplasmic membrane add elections to oxygen, creating highly reactive superoxide radical and hydrogen peroxide
Enzymes converts these into hypochlorite, the active antimicrobial ingredient in household bleach, these chemicals can kill nearby invaders.
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Term
Toll-Like Receptors
(TRLs) |
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Definition
| they are integral membrane proteins produced by phagocytic cells. TLR's act as an early warning system, triggering your body's responses to a number of molecules that are shared by various bacterial or viral pathogens and are absent in humans. |
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Term
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Definition
are protein molecules released by host cells to nonspecifically inhibit the spread of viral infections. Their lack of specifiicity means that interferons produced against one viral invader protect somewhat against infection by other types of viruses as well.
There are 2 types of interferons type I and type II |
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Term
| Type I (Alpha and Beta) Interferons |
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Definition
within hours after infection, virally infected monocytes, macrophages and some lymphocytes secrete small amonts of alpha interferon. Connective tissues as cartilage, tendon, and bone, secrete small amounts of beta interferon when infected with viruses.
Interferons do not protect the cells that secrete them - these cells are already infected with viruses. Instead, interferons activate natural killer lymphocytes and trigger protective steps in neighboring uninfected cells. |
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Term
Type II (Gamma)
Interferons |
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Definition
they are produced by activated T lymphocytes and NK lymphocytes. T lymphocytes are usually activated as part of an adoptive immune response days after an infection has occurred, gamma interferon appears later than either alpha or beta interferon.
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Term
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Definition
a set of serum proteins designed numerically according to the order of their discovery.
These proteins initially act as opsonins and chemotatic factors, and indirectly trigger inflammation and fever.
There are 3 pathways:
The Classical pathway
Alternating pathway
Lectin Pathway |
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Term
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Definition
| in this pathway the various proteins act to "complement" or act in conjunction with, the action of antibodies. |
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Term
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Definition
Activation of the alternatvie pathway occurs independantly of antibodies. The alternative pathway begins with the cleavage of C3 into C3a and C3b. This naturally occurs at a slow rate in the plasma but proceeds no further because C3b is cleavage into smaller fragments alomst immediately.
The alternative pathway is useful in the early stages of an infection, befroe the adaptive immune responses has created the antibodies needed to activate the classical pathway. |
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Term
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Definition
| Lectins are chemicals that bind to specfic sugar subunits of polysaccaride molicules; to mannose sugar in mannan polysaccharide on the surfaces of fungi, bacteria, or viruses. |
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Term
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Definition
is a generl, nonspecific response to tissue damage resulting from a variety of causes, including heat, chemicals ultraviolet, abrasions, cuts, and pathogens.
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Term
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Definition
| develops quickly and is short lived, is typically beneficial, and results in the elimination or resolution of whatever condition precipitated it. |
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Term
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Definition
| long-lasting inflammation which can cause damage to tissues, resulting in disease. |
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Term
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Definition
| part of the body's initial response to an injury or invastion of pathogens is localized dilation of blood vessels in the affected region. |
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Term
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Definition
Fever results when the presence of chemicals called pyrogens trigger the hypothalamic "thermostat" to reset at a higher temperature.
- Chemicals procuced by phagocytes cause the hypothalamus to secrete prostaglandin which resets the hypothalamic thermostat by an unknown mechanism.
- The hypothalamus then communicates the new temp. setting to other parts of the brain, which initiate nerve impulses that produce rapid and repetitive muscle contractions. |
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