Overview of the Immune System Flashcards
All multicellular organisms have developed various mechanisms for defending themselves against ______________.
foreign invaders
Innate immunity is present in all individuals or animals at all times, hence it is the ____________ to microbial invasion.
initial response
Innate immunity does not ________ between pathgoens.
discriminate
Innate Immunity constitues the ______ and ______ lines of host defense.
Innatue Immunity constitues the first and second lines of host defense.
Natural, Naive, or Nonspecific Immunity
Innate Immunity
Acquired or Specific Immunity
Adaptive Immunity
The adaptive immune response is mediated by _______________.
The adaptive immune response is mediated by T and B lymphocytes.
The adaptive immune response is highly _______ for a particular pathogen.
The adaptive immune response is highly specific for a particular pathogen.
In general, it takes the adaptive immune response ___________ for it to become fully functional when a pathogen invades the body.
In general, it takes the adaptive immune response several days for it to become fully functional when a pathogen invades the body.
Unlike the innate immune response, the adaptive response _______ with each successive encounter with the same pathogen.
Unline the innate immune response, the adaptive response improves with each successive encounter with the same pathogen. (i.e. immunologic memory.)
The adaptive immune response constitutes the _________ of host defense.
The adaptive immune response constitues the third line of host defense.
When a microbe ________ innate immune responses, adaptive immune response is then enlisted.
When a microbe **eludes **innate immune responses, adaptive immune response is then enlisted.
Acquired immunity does not operate __________ of innate immunity.
Acquired immunity does not operate **independently **of innate immunity.
Acquired immunity __________ and _________ the nonspecific defense mehcanisms, producing a more effective total response.
Acquired immunity **supplements **and **augments **the nonspecific defense mechanisms, producing a more effective total response.
The first line of defense against microorganisms is the ________ ________ and ________ ________ lining the gastrointestinal, respiratory, and genitourinary tracts.
The first line of defense against microorganisms is the **intact skin **and **mucous membranes **lining the gastrointestinal, respiratory, and genitourinary tracts.
What makes up the first line of defense?
- Intact Skin
- Mucous membranes and their secretions, e.g. mucus.
- Normal Flora
What makes up the second line of defense?
- Phagocytosis
- Inflammation and fever
- Antimocrobial substances
The _____ _____ and the _____ _____ are much more susceptible to infectious agents because their immune responses are suboptimal.
The **very young **and the **very old **are much more susceptible to infectious agents because their immune responses are suboptimal.
As individuals age, they sometimes lose some sense of _____ and ______. As a result they may have poor __________.
As individuals age, they sometimes lose some sense of **smell **and **taste. **As a result they may have **poor nutrition. **
When individuals age appetites often decrease. As a result ________ deficiencies increase.
When individuals age appetites often decrease. As a result **vitamin deficiencies **increase.
Dietary components such as _______ and vitamin A, D, C, and B complex are necessary for healthy immune responses.
Dietary components such as **protein **and vitamin A, D, C, and B complex are necessary for healthy immune responses.
Skin is a ___________ barrier.
Skin is a **mechanical **barrier.
The continuous sheets of tightly packed epithelial cells and keratin layer making up the _________, act as a formidable barrier to the entrance of microorganisms.
The continuous sheets of tightly packed epithelial cells and keratin layer making up the **epidermis, **act as a formidable barrier to the entrance of microorganisms.
Epithelia also produce _________ that have a natural antibiotic function, eg, defensins.
Epithelia also produce **peptides **that have a natural antibiotic function, eg, defensins.
In humans, the epidermis is completely renewed every ______ days.
In humans, the epidermis is completely renewed every 15-30 days. (so-called epithelial turnover).
What is produced by sebaceous oil glands and forms a protective film over the surface of the skin?
Sebum
Sebum contains ______ and ______ acids that inhibit the growth of many microorganisms.
Sebum contains **lactic and fatty acids **that inhibit the growth of many microorganisms.
This process flushes microorganisms from the surface of the skin.
Perspiration
Sweat contains __________.
Sweat contains lysozyme.
_________ washes microorganisms from teeth and gums.
Saliva washes microorganisms from teeth and gums. **It also contains antibacterial agents, eg, lysozyme. **
Components of Gastrointestinal Tract
- Low pH of the stomach
- Normal Flora
- Peristaltic movement (vomit/diarrhea)
- Proteolytic enzymets, bile acids, and pancreatic secretions.
Components of the Respiratory Tract
- Mucociliary escalator
- Coughing and sneezing [speeds up the escalator]
- Alveolar macrophages
How do the eyes contribute to Innate immunity?
Flushing action of tears. Tears also contains lysozyme.
How does the genitourinary tract contribute to innate immunity?
- Urine. Flushing action of urine; acidity of urine. Urine contains lysozyme.
- Vaginal lactic acid.
These are the microorganisms [mostly bacteria, fungi, protozoa] that colonize a host without causing disease.
Normal Flora
Normal flora contribute to host defense by…..
Normal flora contribute to host defense by preventing potential pathogens from colonizing the host.
Normal Flora competes for __________ sites and ________.
Normal flora competes for **attachment **sites and nutrients [competitive exclusion.]
In the large intestines, _________ produce colicins that inhibit the growth of Salmonella spp. and Shigella spp.
In the large intestines, **E.coli **produce colicins that inhibit the growth of Salmonella spp. and Shigella spp.
Normal Flora alters conditions that affect the survival of pathogens such as ____ and ____ availability.
Normal Flora alters conditions that affect the survival of pathogens such as pH and O2 availability.
___________ __________ in the vagina alters its pH to prevent overpopulation by Candida albicans.
Lactobacillus acidophilus in the vagina alters its pH to prevent over population by Candida albicans.
These are proteins that sequester iron, thereby reducing iron available to a pathogen.
Iron-binding proteins
Examples of iron binding proteins…
transferrin, lactoferrin, and haptoglobin
Iron plays a critical role in bacterial respiration as a component of the _______ and the iron-sulfide proteins involved in ________ _________.
Iron plays a critical role in bacterial respiration component of the cytochromes and the iron-sulfide proteins involved in electron transport.
Iron-chelating compounds produced by various pathogenic bacteria that facilitate the uptake of iron by the bacterial cell.
Siderophores
Inhibits the growth of obligate anaerobic bacteria, especially in the lungs.
**Oxygen tension **
Plasma and cell surface proteins associated with lysis of Gram-negative bacteria, chemotaxis of phagocytes, and opsonization [the coating of an antigen or partile that facilitates its uptake into a phagocytic cell.]
Complement
Low molecular weight glycoproteins produced by certain cells in response to viral infections.
**Interferons **
Interferons have _______ and ________ _________ activity.
Interferons have antiviral and immune regulatory activity.
Body temperature ______ replication of some pathogens.
Body temperature **inhibits **replication of some pathogens. (example; FEVER enhances phagocytosis.)
___________ production and __________ proliferation are more efficient at higher body temperatures than at normal levels.
Antibody production and T cell proliferation are more efficient at higher body temperatures than at normal levels.
Fever can be induced by bacterial _______ and ________.
Fever can be induced by bacterial endotoxin (lipopolysaccharide [LPS]) and interleukin-1.
Inflammation is a process which begins following ________ injury to tissue and ends with complete healing.
Inflammation is a process which begins following sublethal injury to tissue and ends with complete healing.
Cause of inflammation may be….
Cause of inflammation may be microbiological, physical, or chemical.
Inflammation results in the bringing of _______ components and cells of the ______ system to the site of ______ damage.
Inflammation results in the bringing of blood components and cells of the immune system to the site of tissue damage.
What are the two types of adaptive immunity?
**Antibody-mediated [humoral] immunity **
Cell-mediated immunity
Antibodies are soluble _______ produced as a result of interaction between a B lymphocyte and an antigen.
Antibodies are soluble proteins produced as a result of interaction between B lymphocyte and an antigen.
The antibody has the ability to combine with the ________ that stimulated its production.
The antibody has the ability to combine with the antigen that stimulated its production.
Where are antibodies found?
- plasma
- lymph
- tissue fluids of the body
Antibodies are most effective in eliminating…..
Antibodies are most effective in eliminating extracellular antigens and bacterial toxins.
An adaptive immune response in which antigen specific T cells play the main role.
**Cell-mediated immunity **
Macrophages and natural killer cells, although __________ cells, are included with T cells in cell-mediated immune responses.
Macrophages and natural killer cells, although **nonspecific cells, **are included with T cells in cell-mediated immune responses.
_____ responses are *most important against intracellular parasites, *in allograft rejection, and in delayed hypersensitivity reactions.
CMI (Cell-mediated immunity) responses are *most important against intracellular parasties, *in allograft rejection, and in delayed hypersensitivity reactions.
The adaptive immune response is divided into ____ phases.
The adaptive immune response is divided into three phases.
What are the three phases of the adaptive immune response?
- The recognition of antigen by antigen-specific lymphocytes
- the activation of the lymphocytes
- the effector phase
The effector phase of the adaptive immune response results in _________ of the antigen.
The effector phase of the adaptive immune response results in destruction of the antigen.
Activation of lymphocytes results in _______ _______.
Activation of lymphocytes results in clonal expansion.
Clonal expansion is the proliferation of _______________ in response to antigenic stimulation and precedes their differentiation into effector cells and memory cells.
Clonal expansion is the proliferation of antigen specific T and B lymphocytes in response to antigenic stimulation and precedes their differentiation into effector cells and memory cells.
Clonal expansion is a critical step in adaptive immunity, allowing rare antigen-specific T and B cells to ___________ so that they can effectively combat the pathogen that elicited the response.
Clonal expansion is a critical step in adaptive immunity, allowing rare antigen-specific T and B cells to increase in number so that they can effectively combat the pathogen that elicited the response.
Following elimination of the antigen, the immune response subsides and _________ is restored.
Following elimination of the antigen, the immune response subsides and homeostasis is restored.
Produces monocytes, neutrophils, basophils, eosinophils, and other cells.
myeloid lineage
produces lymphocytes
** lymphoid lineage **
What is the onset of Innate Immunity?
Rapid [minutes to hours]
What is the onset of Adaptive Immunity?
Slow [days to weeks]
What is the specificity of Innate Immunity?
Antigen nonspecific
What is the specificity of Adaptive Immunity?
Antigen specific
Does Innate Immunity have Memory?
No
Does Adaptive Immunity have memory?
Yes
Does Innate Immunity respond to vaccination?
No
Does Adaptive Immunity Respond to vaccination?
Yes
What cells are involed in Innate Immunity?
Neutrophils, macrophages, NK cells, dendritic cells, etc.
What cells are involved in Adaptive immunity?
T and B lymphocytes
Plasma protein represents a complex mixture of a number of proteins of different _________ and ________ properties.
Plasma protein represents a complex mixture of a number of proteins of different structural and functional properties.
The major plasma proteins are….
albumin, fibrinogen, and globulin
Virtually all of the albumin and fibrinogen, and 50% to 80% of the globulins are produced in the…..
Virtually all of the albumin and fibrinogen, and 50% to 80% of the globulins are produced in the liver.
The globulin proteins [gamma globulins] are produced in the….
The globulin proteins [gamma globulins] are produced in the lymphoid organs and tissues.
Globulins are principally responsible for the body’s _____ and _____ immune responses against invading pathogens.
Globulins are principally responsible for the body’s innate and adaptive immune responses against invading pathogens.
Globulins are comprised of __________ _________ and ____________.
Globulins are comprised of complement proteins and **antibodies. **
This response is directed against self-antigens.
Autoimmunity
Ineffective immune response =
**Immunodeficiency **
Overactive immune response resulting in allergies =
**Hypersensitivity **
Rejection of allograft =
**Transplantation reaction **
These are cell surface molecules expressed on a variety of cell types in the immune system.
**Cluster of Differentiation (CD) Molecules **
CD molecules are identified using __________ antibody.
CD molecules are identified using monoclonal antibody.