Immune System Flashcards
Discuss the function of immune system / Compare and contrast the innate and adaptive immunity / Discuss the cells involved in innate and adaptive immunity / Discuss the etiology, pathogenesis, clinical manifestations of HIV & AIDS / Discuss other immune disorders like hypersensitive disorders
Immune System
Any foreign substance that does not have the characteristic cell surface markers of an individual and is capable of eliciting an immune response = ?
Antigens: Any foreign substance that does not have the characteristic cell surface markers of an individual and is capable of eliciting an immune response.
- Antigens are recognized by specific receptors present on them by lymphocytes/ antibodies
Immune System
Produced in response to an antigen, are protein molecules structured in such a way that they only interact with the antigen that induce their synthesis = ?
Antibody: Produced in response to an antigen, are protein molecules structured in such a way that they only interact with the antigen that induce their synthesis
Immune System
Two distinct and specialized processes of immunity= ?
(1) Innate immunity (natural/ native)
- First responders to insult
- Response is rapid and same at all times
- Nonspecific: does not distinguish between different types of invaders (bacteria, virus)
- Non adaptive: does not remember the previous encounter
(2) Acquired / adaptive immunity
- Slower response; when reintroduced then rapid and intense immune response
- Diversity: Recognize and destroy foreign material like bacteria, fungi
- Specificity: targeted response to a distinct antigen
- Memory: when same organism enters again, body respond’s more rapidly to it and with a stronger reaction
- Self and non-self-recognition
Immune System
How can adaptive immunity be acquired ?
Active adaptive immunity can be acquired in different ways:
- Active acquired immunity
- Development of antibodies in response to an antigen
- Introduction of antigen by either naturally from environmental exposure or artificially by vaccination
Passive acquired immunity:
- When antibodies produced by one person are transferred to another person either naturally (mother to fetus) or inoculation of antibody
Adaptive / Acquired Immunity
Immune System
How does passive acquired immunity occur ?
Passive acquired immunity:
- When antibodies produced by one person are transferred to another person either naturally (mother to fetus) or inoculation of antibody
Adaptive / Acquired Immunity
Immune System
T and B cells migrate throughout the body through ?
- Humoral = B cells
- Cell mediated = Tcells
- Response from these two types of immunity overlap andinteract considerably.
- T and B cells migrate throughout the body via blood, lymph, and lymph nodes.
Adaptive / Acquired Immunity
Immune System
Humoral / B Cells = ?
Humoral / B Cells:
- Involving antibodies / immunoglobulins
- B lymphocytes: originate and mature in bone marrow
- B cells are very effective against organisms that are free floating in the body that can very easily be reached and neutralized.
- B lymphocyte-plasma cellcan produce5 types of antibodies
- IgG
- IgM
- IgA
- IgD
- IgE
Immune System
T lymphocytes originate in ?
(a) T lymphocytes:
- Originate in bone marrow andmature in Thymus
- T cells can recognize the hidden organisms, searchthem out and destroy on acell-to-cellbasis
- Helper T cells (T4 lymphocyte, CD4 lymphocyte), 75% of T cells
- Assist B cells to mature and produce antibodies
- Activating macrophages and helping them destroy large bacteria
- Helping other T lymphocytes (cytotoxic T cells/ CD8 cells) recognize and destroy virally infected cells
- HIV destroys these helper T cells and leaves the body at risk of infections
- Suppressor T cells: suppresses the activation of immune system
- Cytotoxic T cells (CD8): Toxic to the antigens; killing the antigens
- Memory T cells: Remember what they crossed paths with in the body
Cell Mediated Immunity: T Cells
Immune System
Factors altering the immune system = ?
- Aging
- Nutrition:
- Deficits in calories, protein intake or vitamins like A and E can cause deficiency in T cell function and numbers.
- Zinc deficiency: impairs T and B cell function
- Burns:
- Decrease external defense, decrease neutrophil function, decreased cell mediated and humoral responses
- Sleep disturbances
- Presence of concurrent illness and disease like malignancy, diabetes, HIV infection
- Drugs:
- Immunosuppressive drugs, cancer chemotherapeutic drugs suppress the immune response
- Surgery / anesthesia:
- Suppresses T and B cell function up to 1 month post operatively (Splenectomy).
Immune System
Central immune structures include bone marrow and the thymus.
- What are their functions in regard to immune defense = ?
Function of Immune Defense Components
Bone Marrow:
- Production of lymphocytes
- Maturation of B lymphocytes
Thymus:
- Gland located in the mediastinum
- Differentiation and maturation of lymphocytes
Immune System
Peripheral immune structures include lymphnodes, spleen, and other lymphatic mucosal tissues such as the tonsils, peyer patches, appendix.
- What are their functions in regard to immune defense = ?
Lymphnodes:
- Round masses of lymphatic tissue
- Spread out among lymphatic vessels
Spleen:
- Site of lymphatic migration
Lymphatic mucosal tissue (tonsils, peyer patches, appendix):
- Site of lymphatic aggregation
Immune System
The primary cellular components involved in immune defense include T Lymphocytes and B Lymphocytes.
- What are their functions in regard to immune defense = ?
T Lymphocytes:
- Matured in thymus
- Essential in adapative cell-mediated immunity
- Desctruction of cellular antigens
- Promote antibody production by B Lymphocytes
- Account for 60% of blood lymphocytes.
B Lymphocytes:
- Matured in bone marrow
- Essential in mediating adaptive humoral immunity
- Production of antibodies/immunoglobulins
- Account for 10-20% of blood lymphocytes
Immune System
Accessory cellular components involved in immune defense include:
- Macrophages
- Neutrophils
- Dendritic cells
What are their functions in regard to immune defense?
Macrophages:
- Essential in mediating innate immunity
Neutrophils:
- Bind invading microbes to cell surface receptors
Dendritic cells:
- Process and present antigen to T and B lymphocytes, stimulating adaptive immune response.
- Phagocytosis to prevent colonization, entry, and spread of microbes
Immune System
What should we know about exercise immunology?
- Depending upon the intensity, activity or exercise can enhance or suppress the immune function.
- Moderate intensity exercise- enhances immune system = 50-70% of the maximal heart rate.
- Strenuous/ intense/ long duration exercise impairs the immune system= Leave host open to microbial agents during open window
Immune System
Impact of exercise on:
- Neutrophils
- NK cells, and
- Lymphocytes
Neutrophils:
- Exercise: rise in blood levels of neutrophils.
- After brief gentle exercise- count returns to baseline.
- After strenuous exercise- return to normal may take 6-24 hours.
NK cells:
- Once the person is accustomed to a given exercise level, the NK enhancement falls off.
- After intense exercise, number and activity of NK cells decline, maximum reduction occurs 2-4 hours after the exercise, return to baseline soon
Lymphocytes:
- Increase but decrease below normal for several hours after intense exercise