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Immune System Mariah Mancinas P:1 - Coggle Diagram
Immune System Mariah Mancinas P:1
Major functions of the Lymphatic & Immune systems
Maturation which is when Lymphocytes are “educated” in a 2-3 day process and mature in primary lymphoid organs
They are educated for two reasons. Immunocompetence: lymphocytes must be able to recognize only 1 specific antigen and Self-tolerance: lymphocytes must be unresponsive to own
Antigen encounter and activation̈: lymphocyte’s first encounter with antigen triggers lymphocyte to
develop further, Lymphocyte is selected to differentiate into active cell by binding to its
specific antigen
Proliferation and differentiatioń, B and T memory cells and effector T cells circulate continuously.
Antigen receptor diversity:Genes, not antigens, determine which foreign substances the immune system will
recognize
Primary immune response: cell proliferation and differentiation upon exposure to
antigen for the first time
Secondary immune response:Re-exposure to same antigen gives faster, more prolonged, more effective
response
Location of Lymphatic organs and their functions
location of the the lymnodes and spleen are towards the abdominal area and their functions are to filter out pathegoens.
Purpose and examples of First, Second and Third line of defense
First Layer of defense produces Acid which is the acidity of skin and some mucous secretions, Enzymes which are lysozyme of saliva, respiratory mucus, and lacrimal fluid kills many
microorganisms. Lastly it produces Mucin which is in the repiratory track.
The Third line of defense attacks any foreign substance and takes Longer to react than innate.
First Line of Defense: External Bosy Membrane, Skin and Mucous
Second Line of Defense: antimicrobial proteins, phagocytes, and other
cells
The Purpose of The second Line of defense is to recognition receptors that recognize and bind
tightly to structures on microbes, disarming them before they do any harm
Innate(natural) immune defenses and Adaptive(acquired) immune defenses
Innate Defense system: Consists of First and second Line of defenses
Adaptive Defense system: Consists of the Third Line of Defense
Innate Defenses: Phagocytes, Natural Killer cells, Inflammation, Antimicrobial proteins and fever.
Adaptive contains: Humoral immunity and Cellular Immunity
Innate and adaptive defenses are intertwined they both elease and recognize many of the same defensive molecules as well as working together like
the Innate responses by releasing proteins that alert cells of adaptive system to foreign
molecules
Adaptive immune system is a specific defensive system that eliminates almost any
pathogen or abnormal cell in body
Humoral response and cellular response
Cellular Immunitÿ: They are Lymphocytes that act against target cell
Humoral immunity:Antibodies that are produced by lymphocytes and will circulate freely in body fluids. They also bind to a target cell temporarily for destruction.
Cellular: Directly is by killing infected cells
Cellular: Indirectly is by releasing chemicals that enhance inflammatory response and or
activating other lymphocytes or macrophages
CD4 cells usually become helper T cells (TH) that can activate B cells, other T
cells, and macrophages; direct adaptive immune response
CD8 cells become cytotoxic T cells (TC) that are capable of destroying cells
harboring foreign antigens
Antigens and antibodies
Antigens: substances that can mobilize adaptive defenses and provoke an immune
response
Antigens target all immune responses.
Self-antigens: all cells are covered with variety of proteins. They are located on the surface that are
not antigenic to self, but may be antigenic to others in transfusions or grafts
Antigens presenting cells: Dendritic cells,Macrophages and B cells.
Dendritic cells: Found in connective tissues and epidermis and Phagocytize pathogens that enter tissues, then enter lymphatics to present
antigens to T cells in lymph node
Macrophages: Widely distributed in connective tissues and lymphoid organs and they Present antigens to T cells, which not only activates T cell, but also further
activates macrophage
B lymphocytes: Do not activate naive T cells and Present antigens to helper T cell to assist their own activation
Basic antibody structure:Overall T- or Y-shaped antibody monomer consists of four looping polypeptide
chains linked by disulfide bonds
Antibody classes:IgM, IgA, IgD, IgG, and IgE
Antibodies do not destroy antigens; they inactivate and tag them
Antigen-antibody complexes do not destroy antigens; they prepare them for
destruction by innate defenses
Artificial vs. Naturally acquired immunity
Naturally acquaried immunity happends with contact through diseas agent.
Artifical only happens with deliberate actions of exposure.
Passive vs. Active immunity
Active humoral immunity occurs when B cells encounter antigens and produce
specific antibodies against them
Naturally acquired: formed in response to
actual bacterial or viral infection
Artificially acquired: formed in response to
vaccine of dead or attenuated pathogens
Passive humoral immunity occurs when ready-made antibodies are introduced into
body
Naturally acquired: antibodies delivered to fetus via placenta or to infant
through milk
Artificially acquired: injection of serum, such as gamma globulin
– Protection immediate but ends when antibodies naturally degrade in body
Cells involved in the immune system and their functions
Phagocytes: white blood cells that ingest and digest (eat) foreign invaders
Macrophages: develop from monocytes and are chief phagocytic cells; most robust
phagocytic cell
Natural killer Cells: Kill by inducing apoptosis in cancer cells and virus-infected cells
Dendritic cells: Found in connective tissues and epidermis and Phagocytize pathogens that enter tissues, then enter lymphatics to present
antigens to T cells in lymph node
Macrophages: Widely distributed in connective tissues and lymphoid organs and they Present antigens to T cells, which not only activates T cell, but also further
activates macrophage
B lymphocytes: Do not activate naive T cells and Present antigens to helper T cell to assist their own activation
Cytotoxic T (TC) cells: Activated TC cells circulate in blood and lymph and lymphoid organs in search of
body cells displaying antigen they recognize
Disorders associated with the Immune system
Pus: creamy yellow mixture of dead neutrophils, tissue/cells, and living/dead pathogens
Immunodeficiency: congenital or acquired conditions that impair function or production
of immune cells or molecules
Severe combined immunodeficiency (SCID) syndrome: genetic defect with marked
deficit in B and T cells
Hodgkin’s disease is an acquired immunodeficiency that causes cancer of B cells,
which depresses lymph node cells and thus leads to immunodeficiency
Human immunodeficiency virus (HIV) cripples immune system by interfering
with activity of helper T cells
Autoimmune disease results when immune system loses ability to distinguish self from
foreign
Autoimmunity: production of autoantibodies and sensitized TC cells that destroys body
tissues