Immune System Flashcards
Function of Immune System
- distinguish self from non-self
- protect from foreign substances
- nonspecific immunity
- provide specific or acquired immunity
Lymphoid Organs/Tissues
- adenoids
- tonsils
- lymph nodes
- lymphatic vessels
- thymus
- spleen
- bone marrow
- ileum (lymph nodes)
- liver
Bone Marrow
-produce B cells
Thymus
-produce T cell
and Thymosine
Lymph Nodes
-trap and process antigens
Spleen
- filters antigens from blood
- systemic protection
Liver
- reduce amount of toxins that can impair GI lining
- filters all bloood from GI system
Mucosa
- associated with lymphoid tissues
- provide lymphocytic responses to nearby tissues
- lines respiratory, digestive, urogenital tracts
Examples of Antigens
- virus
- food item
- pollen
- medication
- transplanted cells/tissue
- bacteria
- fungi
- protozoans
- parasites
Major Histocompatability Complex
- cell surface proteins that provide cell-to-cell communication regarding presence of antigens
- On every cell
- as unique as a finger print
MHC
-major histocompatability complex
Antigen
-substances that stimulate an immune response
Antigens also known as:
-immunogens
Antibodies
- immunoglobulins
- proteins that recognize antigens
-antigen-binding sites are complementary to antigens they recognize
Types of Immunoglobulins
- IgA
- IgG
- IgM
- IgD
- IgE
IgA
- prevent attachment of viruses/bacteria to epithelial tissues
- mucosal lining
IgG
- gamma globulin
- most abundnt
- crosses placenta for fetal immunity
IgM
- first circulating antibody made by newborn
- used to detect newborn infection
IgD
-initiates blood immune response
IgE
-involved in inflammation and allergic response
Granulocytes
- Basophils
- Eosinophils
- Neutrophils
Lymphocyte Types
- B Cells
- T Cells
- NK Cells
Monocytes
-Macrophates
Innate Immunity Cells
- Basophils
- Eosinophils
- Neutrophils
- NK Cells
Acquired Immunity Cells
- B Cells
- T Cells
Lymphocytes
-mononuclear immunocytes that provide humoral and cell-mediated immunity
Lymphocytes
- mononuclear immunocytes that provide humoral and cell-mediated immunity
- 25-33% of total WBC count
Macrophages
- large mononuclear phagocyte providing phagocytosis
- contain infections
- help initiate immunological responses
-3-7% of total WBC Count
Monocytes
-migrate into tissues where they mature into macrophages
Neutrophil
- segmented polymorphonuclear granulocyte
- form pus
-57-67% of total WBC Count
Neutrophils can:
-squeeze through capillary walls and into infected tissue where they kill invaders then engulf the remnants by phagocytosis
Basophil
- segmented polymorphonuclear granulocyte
- 0-0.075% of total WBC Count
Eosinophil
- segmented polymorphonuclear granulocyte
- 1-4% of total WBC Count
NK Cells
-natural killer cells
Natural Killer Cells
- large granular lymphocytes kill some tumors and virus-infected cells w/o prior exposure
- can be used to treat cancer
Lymphocytes are responsible for:
-cell-mediated and humeral-mediated immunity
Lymphocytes recognize and activate:
-specific immune responses
Cytokines
-regular proteins that modulate the reaction of the host to antigens
Cytokines include:
- interleukins (IL)
- Interferons
- Tumor NEcrosis Factors (TNF)
- Colony-Stimulating Factors (CSF)
Interferons
- produced by virally infected cells early in infection to limit the spread of infection
- protect neighboring cells (non-infected) cells from invasion
- inhibit tumor growth
Lines of Defense
- 1st
- 2nd
- 3rd
First Line of Defense
-external barriers prevent the infecting agent from penetrating cells and tissues
2nd Line of Defense
-inflammatory response and phagocytosis
3rd Line of Defense
- acquired immune response
Types of Acquired Immunity
- passive
- ative
Active and Passive Immunity may be:
-natural or artificial
Acquired Immunity Components
- Humoral (B cells)
- Cell-mediated (T cells)
Acquired Immunity Components
- Humoral (B cells)
- Cell-mediated (T cells)
Non-Specific Lines of Defense
- Skin
- Mucous Membranes
- Chemical balance
- Antimicrobial substances
- Fever
- Phagocytic Cells
- Complement system/cytokines
- Natural killer cells
Specific Lines of Defense:
Lymphocytes
-T and B cells that recognize specific pathogens are part of the acquired immune response
Specific Lines of Defense:
Memory Lymphocytes
-have memory of antigen that last a long time
Specific Lines of Defense:
Lymphocytes can:
-self-destruct or change into a new cell when defense is completed
Innate Immunity
-inborne non-specific aspects of tissue defense -first line of defense to prevent entrance of pathogens -Skin/mucosal barriers -non-specific inflammatory response
Innate Immunity response is always
-the same intensity regardless of number of times pathogen is encountered
What Happens in Innate Immune Response (Mechanisms)
- sloughing of skin
- phagocytosis of bacteria
- destruction of pathogens by acid secretions
- digestive enzymes in GI tract
Acquired Immunity
- specific and memory
- after birth
- destroy foreign substances
- prevent proliferation of malignant cells
- occurs after invasion by foreign agent
- pathogens in body trigger response
Acquired Immunity Over Time
-response will increase and speed and intensity each time specific pathogen is encountered
Active Acquired Immunity
- contact with antigen or product derived from antigen
- antibodies or T-cell response produced by hose in response to contact
Passive Acquired Immunity
- contact with antibodies from actively-immunized person or via innoculation
- triggers temporary acquired immune response
Examples of Active Acquired Immunity
-contact with infectious agent or product of infectious agent
Examples of Passive Acquired Immunity
- injection of serum from individual previously immunized or recovered from disease
- injection of serum from animal immunized with tetanus toxoid
- placental transfer of antibodies from mom to fetus
- transfer of antibodies in mom’s milk
B-Cell
- humoral immunity
- develops circulating antibodies to attack antigens
- antibodies bind to foreign body
T-Cell
- cell-mediated immunity
- activates formation of lymphocytes designed to destroy the foreign agent
B-Cell
- humoral immunity
- develops antibodies to attack antigens
- antibodies bind to foreign body
- recognizes one antigen
- produce memory cells for future responses
T-Cell
- cell-mediated immunity
- recognizes one antigen
- activates formation of lymphocytes designed to destroy the foreign agent
- attacks antigen directly
T Cells Produce:
- memory cells
- T-cytotoxic (killer) cells
- T-Helper Cells
- T-Suppressor cells
- Lymphokine-Producing Cells
Primary Immune response
-production of specific antibodies (immunoglobulins)
Secondary Immune response
-increase activation with increased exposure of memory cells to the antigen
Secondary Immune response
-increase activation with increased exposure of memory cells to the antigen
Stem cells
- differentiate in bone marrow
- involved in humoral/antibody-mediated immunity
Activated B cells:
-incapacitate the antigen
B cells mature into:
-plasma B cells, which produce antibodies
Processed T cells leave the:
-thymus and spread to lymphoid tissues throughout the body shortly after birth
T Cells recognize:
-pathogens, search them out and destroy them
T Cells recognize:
-pathogens, search them out and destroy them
T Lymphocytes are capable of:
-turning on/off entire immune system
T8 cells
-cytotoxic cells are primary active responders
Cell-Mediated response is important in
- recognizing body’s own tissue
- loss can lead to autoimmune disorder
Cell-Mediated response is important in
- recognizing body’s own tissue
- loss can lead to autoimmune disorder
Link Between Immune System and CNS
- ANS
- Neuroendocrine outflow (pit gland)
Activated immunocompetent cells can:
-cross blood-brain barrier
Regulation of Immune Response
- initiation by antigens
- intercellular recognition & binding
- intercellular signaling
Hormonal Regulation of Immune Response
- thymus gland
- ant pit
Neural Influences on Regulation of Immune Response
-sympathetic NS
innervates thymus, bone marrow, spleen, lymph nodes
Apoptosis
- auto-destruction of cells
- if unable to defend against mutation cell self-destructs
Apoptosis response decreases:
-decreases with age
Apoptosis is enhanced by:
-exercise
Factors Influencing Immunity
- trauma
- disease
- pollutants
- radiation
- UV light
- drugs
- age
- gender
- nutrition
- genetics
- reproductive status
- STRESS
GI Acidity with age:
-decreased acidity
Bladder with age:
less elastic
Thymus with age
-turns to fat
AGE:
innate response
-not always automatic in elderly
AGE:
-lymphocytes
-react to infection differently
In elderly (>70) more likely to produce
auto-antibodies that attack self
Moderate Exercise:
On Immune Cells
-increased #
most increase during and after
Strenuous Exercise:
On Immune Cells
-depressed
Strenuous Exercise:
On Immune Cells
-depressed
Immunodeficiency Syndromes
- primary
- secondary
- iatrogenic
Primary Immunodeficiency
- defect of T cells, B cells or lymphoid tissue
- congenital condition
Secondary Immunodeficiency
- underlying disease/factor impairing response
- follows disease/event
Iatrogenic Immunodeficiency
- induced by drug or physical agents
ex. chemo, corticosteroids, radiation
Iatrogenic Immunodeficiency
- induced by drug or physical agents
ex. chemo, corticosteroids, radiation, splenectomy
