Lymphatic system (immunity) Flashcards
the ability to resist damage from pathogens
Immunity
Immunity can be categorized as __________ and _________.
Innate immunity; adaptive immunity
also called nonspecific immunity, wherein the body recognizes and destroys certain foreign substances, but the response to them is the same each time the body is exposed
Innate immunity
also called specific immunity, wherein the body recognizes and destroys foreign substances, but the response to them is faster and stronger each time the foreign substance is encountered.
Adaptive immunity
the characteristics of adaptive immunity but not of innate immunity
specificity and memory
the ability of adaptive immunity to recognize a particular substance
specificity
the ability of adaptive immunity to “remember” previous encounters with a particular substance
memory
the response in adaptive immunity is _____, ______, and ______ than innate immunity
faster; stronger; longer-lasting.
__________ includes body defenses that are present at birth and genetically determined, while ________ includes body defenses that are acquired through a person’s lifetime, depending on exposure to different
microorganisms.
innate immunity; adaptive immunity
The main components of innate immunity are (1) _________ that prevent microbes from entering the body or that physically remove them from body surfaces; (2) _________ that act directly against microorganisms or activate other mechanisms, leading to the destruction of the microorganisms; and (3) ____________________.
- physical/surface barriers
- chemical mediators
- cells involved in phagocytosis and the production of chemicals that participate in the immune response.
The body’s first line of defese, such as the skin and mucous membranes, that prevents microorganisms and chemicals from entering the body.
Physical/surface barriers
Examples of how surface barriers remove microorganisms and other substances from the body
The substances are washed from the eyes by tears, from the mouth by saliva, and from the urinary tract by urine.
are molecules responsible for many aspects of innate immunity
chemical mediators
chemical mediators on the surface of cells that kill microorganisms or prevent them from entering the cell
lysozyme, sebum, and mucus,
chemical mediators that promote inflammation by causing vasodilation and increasing vascular permeability, attract white blood cells, and stimulate phagocytosis.
histamine, complement, and eicosanoids
proteins or peptides secreted by cells that bind to receptors on cell surfaces,
stimulating a response; regulate the intensity and duration of immune responses and stimulate the proliferation and differentiation of cells.
Cytokines
Examples of cytokines
interferons, interleukins, and lymphokines
-the most abundant type of white blood cell
-small, phagocytic cells produced in large numbers in red bone marrow and released into the blood
-usually the first cells to enter infected tissues from the blood in large numbers
-become phagocytic on encountering infectious material in the tissues
-eventually self-destruct after killing the pathogen and become pus
-release chemical signals, such as cytokines and chemotactic factors, that increase the inflammatory response by recruiting and activating other immune cells.
neutrophils
- “big eaters” large phagocytic cells
- Most effective phagocyte; responsible for most of the phagocytic activity in the late stages of an infection
- are derived from white blood cells called monocytes that leave the blood stream and enter the tissues
- located beneath the free surfaces of the body, provide protection in these areas by trapping and destroying microorganisms entering the tissues
Macrophage
an accumulation of dead neutrophils, dead microorganisms, debris
from dead tissue, and fluid
pus
white blood cells derived from red bone marrow; are motile cells that can leave the blood and enter infected tissues
basophil
cells filled with basophil granules that are present in tissues and release histamines that help cause vasodilation in response to wound, infection, or irritant; nonmotile cells in connective tissue, especially near
capillaries
mast cells
- white blood cells.
- increases in response to parasitic infections.
- secrete enzymes that effectively kill some parasites.
- greatly increase in the case of an allergic reaction with much inflammation.
Eosinophils
- part of a small group of large granular lymphocytes
- account for up to 15% of lymphocytes
- recognize classes of cells, such as tumor cells or virus-infected cells in general, rather than specific tumor cells or cells infected by a specific virus
- not phagocytic: kill by directly contacting the target cell, inducing it to undergo apoptosis (programmed cell death), or by releasing chemicals that damage cell membranes and cause the cells to lyse
Natural Killer (NK) Cells
- Anti-microbial proteins released by virus-infected cells and certain lymphocytes
- act as chemical messengers to protect uninfected tissue cells from viral takeover
- mobilize the immune system
- proteins that interfere with virus production and infection
- bind to the surface of neighboring cells and stimulate them to
produce antiviral proteins - protect against viral infection
Interferons
A group of bloodborne proteins that protect the body by destroying abnormal cells or enhancing other components of immunity, when activated:
- lyse microorganisms
- enhance phagocytosis by opsonization
- intensify inflammatory and other immune responses
- attract immune system cells to sites of infection and promote inflammation
Complement
Complement proteins can also attach to the surface of bacterial cells and stimulate macrophages to phagocytize the bacteria. This process is called ___________.
Interferons
s the endocytosis and destruction of particles by cells called phagocytes
Phagocytosis
Complex biological process by which body responds to pathogens and irritants
Inflammatory response
the ability of moving towards the source of substances or the directed migration of cells towards a chemoattractant.
chemotaxis
The chemical mediators produce several effects:
(1) ________ increases blood flow, bringing phagocytes and other white blood cells to the area;
(2) __________ and other white blood cells leave the blood and enter
the tissue;
(3) increased _________ allows fibrinogen and complement to enter the tissue from the blood
- Vasodilation
- phagocytes
- vascular permeability
- Systemic response to invading microorganisms initiated by pyrogens
- high body temperature inhibits microbes from multiplying and enhances body repair processes
- increases the metabolic rate of tissue cells in general, speeding up repair processes
fever
.an inflammatory response confined to a specific area of the body. Its
symptoms include redness, heat, and swelling due to increased blood flow and increased vascular permeability, as well as pain caused by swelling and by chemical mediators acting on pain receptors.
Local inflammation
an inflammatory response that occurs in many parts of the body
Systemic inflammation
- can recognize, respond to, and remember a particular substance
- the system must first “meet” or be primed by initial exposure to a specific foreign substance (antigen) before it can protect the body against that
substance.
Adaptive immunity
Substances that stimulate adaptive immunity
antigens
antigens not produced by the body but are introduced from outside
foreign antigens
an overreaction of the immune system in some people
allergic reaction
molecules the body produces to stimulate an adaptive immune system response. The response to it can be beneficial or harm
Self-antigens
can develop when self-antigens stimulate unwanted tissue destruction
autoimmune disease
Protection against extracellular antigens; primary cells involved are B cells which produce antibodies
- involves the production of antibodies in response to extracellular antigens
Antibody-Mediated Immunity
Protection against intracellular antigens; involves T-cells; cytokines are primary secretory products
Cell-mediated imunity
_________ are responsible for producing the effects of cell-mediated immunity. __________ and _________ can promote or inhibit the activities of both antibody-mediated immunity and cell-mediated immunity
cytotoxic T cells; Helper T cells; regulatory T cells
- unresponsiveness of lymphocytes to a specific antigen
- prevent the immune system from responding to self-antigens
Tolerance
Y-shaped proteins produced in response to an antigen
- also called immunoglobulins (Ig), because they are globulin proteins involved in immunity.
- its five classes are IgG, IgM, IgA, IgE, and IgD
Antibodies
- includes a series of cell divisions, cell differentiation, and antibody production
- caused by the first exposure of a B cell to an antigen for which it is specific \
primary response
- also called memory response, occurs when the immune system is exposed to an antigen against which it has already produced a primary response
- provides better protection than the primary response
- includes the formation of new memory B cells, which protect against additional exposures to the antigen
secondary response
lyse cells and produce cytokines
cytotoxic T cells
Four types of adaptive immunity
- active natural
- active artificial
- passive natural
- passive artificial
occurs when another person or an animal develops immunity and the immunity is transferred to a non-immune individual
passive immunity
implies that contact with an antigen or antibody occurs as part of everyday living and is not deliberate
natural exposure
also called immunization, is the deliberate introduction of an antigen or antibody into the bod
artificial exposure
_______ immunity can last longer than ___________ immunity
active; passive
results from natural exposure to an antigen, such as a disease-causing microorganism, that stimulates the immune system to respond against the antigen.
Because the individual is not immune during the first exposure, he or she usually develops the symptoms of the disease
Active natural immunity
an antigen is deliberately introduced into an individual to stimulate the immune system. This process is called vaccination, and the introduced antigen is a vaccine that is usually administered by injection
Active artificial immunity
is achieved by administering specific antibodies or antiserum from one individual to another unimmunized individual, for a particular antigen
passive artificial immunity
results when antibodies are transferred from a mother to her child across the placenta before birth
passive natural immunity
Inflammation of the lymphatic vessels often results in visible red streaks in the skin that extend from the site of infection
LYMPHANGITIS
Inflammation of the lymph nodes; nodes become enlarged and tender as pathogens are trapped and destroyed
LYMPHADENITIS
Serious bacterial infection that is transmitted primarily by flea bites (from fleas found in rats) which results in a swollen and inflamed lymph node in the armpit or groin
BUBONIC PLAGUE
Abnormal accumulation of lymph in tissues, caused by long, slender
roundworms transferred to humans by mosquito bites; adult worms lodge in lymphatic vessels and block lymph flow, so that a limb can become permanently swollen and enlarged.
ELEPHANTIASIS
