chapter 3 Flashcards
Primary immune response-
takes about 1 week b/c immune system has not previously encountered the antigen
what makes IgB?
B cells
what are B cells?
Responsible for production of antibodies Involved in humoral immunity Against bacteria, fungi , parasites, pollen outside body cells Mature in bone marrow Proceed to spleen and lymphoid tissue Become plasma cells upon contact with antigen B-memory cells Can quickly form clone of plasma cells
IgE
Appears in trace amounts
Attaches to mast cells
Important in hay fever, skin allergies
would some one suffering from an allergy have high or low blood pressure?
low
IgD
Does not appear in blood
Bound exclusively to cell membrane of B cells
Activates B cells to recognize antigen and undergo clonal expansion
T cells?
T-cells stimulated only by contact w/ antigen bound to a cell membrane
T-cell then migrate to site for action (takes days)
“Delayed or cellular immunity”
Cytoxic T cells-
target and destroy, mostly cancer cells, viruses, some bacterial/fungal
Helper T cells-
Facilitate the immune activities of B cells and other T cells
Suppressor T cells-
Shut down the immune response, prevent auto immune dz
Memory T cells-
Enable the immune system to mount a rapid secondary response
Physical/Chemical barriers: ( immunity against non-self)
Skin, mucus membranes, gastric acid (non-immune defense)
Lymphatic system: (immunity against non-self)
Branching network of lymphoid vessels, houses immune cells
Immune system: (immunity against non-self)
Cellular/molecular defense. Key players are WBCs. (Specific/ Acquired/Adaptive
Primary lyphoid organs
Bone marrow
Thymus
Lymphatic system
network of small lymph vessels
Secondary lymph organs
Tonsils
Lymph nodes
Nodules of lymphoid tissue in intestinal and respiratory tract
Spleen
Function of lymphatic system
House and support immune cells
Filter tissue fluid for non-self content
In the intestines only, to absorb fat and deliver it into the blood
Lymph fluid-
identical to interstitial fluid-contains water, electrolytes, and little protein
Lymph nodes-
Composed of immune system cells, approx. 500 in fat and other soft tissue
Mucosal
associated lymphoid tissue (MALT)- situated at sites where pathogens frequently enter the body
Innate- natural- present at birth
, attack any non-self substance.
Does not require prior exposure, occurs within minutes and is fast and broad. Example???
Adaptive- Acquired/Specific
Slower, programmable.
Learns characteristics of non-self material. Memorized for use in future.
Antigens (Immunogens)
Are foreign substances or human cell surface antigens
Composed complex proteins
Activate system to produce matching antibodies
Antigens representing self present on individual’s cell membrane
Haptens
small non-protein molecules can stimulate immune reaction by combining w/ normal self-protein i.e. skin rash of poison ivy
Macrophages
Large phagocytic cells
Derived from blood monocytes
Migrate freely in blood
Engulf foreign material
Display antigens of foreign material to lymphocytes, thus initiates immune response
Secrete chemicals
i.e., monokines and interleukins- such as in inflammatory response = secondary immune response
Dentritic cells
Evolve from monocytes or lyphocytes
Remain fixed in place, concentrated in lymphoid organs and in tissues exposed to environment i.e. skin, lining of respiratory tract, lining of GI tract
*Both dentritic cells and macrophages are also called antigen presenting cells (present antigen to T lymphocytes)
Lymphocytes- WBCs primary cell in immunity
Lymphocytes circulating in blood comprise 5% of all lymphocytes, 95% reside in lymphoid organs and tissues
One line of fetal lymphocytes migrate to thymus-T cells
Cells that remain in the bone marrow- B cells
T- lymphocytes
Compromise two-thirds of blood lyphocytes
Are the agents of cellular (delayed) adaptive immunity
B- lymphocytes
Compromise one-fourth of blood lymphocytes
Are the agents of humoral (antibody) adaptive immunity
Natural Killer (NK) cells
Compromise 10% of blood lymphocytes
Fast and aggressive at killing virus infected and tumor cells
Destroy w/o prior exposure
Lymphocytes
B-lymphocytes
Responsible for production of antibodies Involved in humoral immunity Against bacteria, fungi , parasites, pollen outside body cells Mature in bone marrow Proceed to spleen and lymphoid tissue Become plasma cells upon contact with antigen B-memory cells Can quickly form clone of plasma cells
IgG
Smallest, most abundant in blood
Neutralizes microoranisms
IgM
Largest immunoglobulin
Attacks microorganisms and is produced rapidly
IgA
Most abundant in mucosal secretions
Tears
Saliva and mucous membranes
Colostrum
IgE
Appears in trace amounts
Attaches to mast cells
Important in hay fever, skin allergies
IgD
Does not appear in blood
Bound exclusively to cell membrane of B cells
Activates B cells to recognize antigen and undergo clonal expansion
How do antibodies work?
Neutralize the function of antigen
Cause cell death by rupturing the cell membrane
Inciting an inflammatory reaction to neutralize or digest the microbe
Making microbe more susceptible to phagocytosis by inflammatory cells
Combination of antibody-antigen is IMMUNE COMPLEX
Cytoxic T cells-
target and destroy, mostly cancer cells, viruses, some bacterial/fungal
Helper T cells-
Facilitate the immune activities of B cells and other T cells
Suppressor T cells-
Shut down the immune response, prevent auto immune dz
Memory T cells-
Enable the immune system to mount a rapid secondary response
Major histocompatibility complex (MHC)
Mechanism by which antigens are displayed on immune cells
Glyocoprotein complex on the surface of cells to allow the immune system to recognize it as self or non-self
MHC 1-
Present on all cells, except RBCs, gives signal that they are self or non-self
MHC 2-
only on macrophages and dendritic cells, gives signal for immune cells to go looking for the pathogen which they are presenting
Complement System
Activated during immune reactions with IgG or IgM
Group of inactive proteins circulating in blood
Numbered C1 to C9, floating in blood
Causes cell damage and further inflammation when activated
Chemical Mediators
Involved in inflammation and immune reactions i.e., histamine, interleukins Variety of functions Signaling Causing cellular damage
Active natural immunity
Natural exposure to antigen
Development of antibodies