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Lymphatic/Immune System Kayla Ramirez - Coggle Diagram
Lymphatic/Immune System Kayla Ramirez
Major functions of the Lymphatic & Immune systems
Tissue Fluid and Lymph
• Tissue fluid that has entered a lymphatic capillary
• Lymph formation depends on tissue fluid formation
Main functions of lymph nodes:
• Filter lymph and remove bacteria and cellular debris before lymph is returned to the blood
• Immune surveillance: Monitor body fluids; performed by lymph is returned to the blood
• Lymph nodes are also centers of lymphocyte production
• Lymphocytes attack viruses, bacteria and parasitic cells that enter a lymph
• Macrophages engulf and destroy foreign particles, debris, and damaged cells
Location of Lymphatic organs and their functions
Practical Classification of Adaptive Immunity 1
Immunity can be active or passive:
• Active immunity is obtained through antigen exposure; an
immune response occurs in the person, in which antibodies and
memory B cells are produced; this is long-lasting immunity
• Passive immunity is obtained by receiving antibodies; since
there is no antigen contact and no immune response occurs, no
memory B cells are produced; this is short-term immunity
Immunity can be acquired by natural events, such as getting a
disease, or induced artificially, by an injection
Disorders associated with the Immune system
Hypersensitivity 1
Hypersensitivity reactions:
• Excessive immune responses to a normally harmless antigen, that
may lead to tissue damage
• Some can occur in almost anyone, while others require hereditary
predisposition
• Immediate-reaction hypersensitivity (allergy):
• Allergy mediators cause mucus production, vasodilation, and bronchoconstriction,
resulting in an inflammatory response
• Allergy mediators sometimes flood the body, resulting in anaphylaxis, a severe
form of immediate-reaction hypersensitivity, which can be life-threatening
• Antibody-dependent cytotoxic reactions:
• Example: a transfusion reaction to mismatched blood
• Delayed-reaction hypersensitivity:
• Results from repeated exposure of skin to certain substances
Innate(natural) immune defenses and Adaptive(acquired) immune defenses
• Innate (nonspecific) defenses:
• Guard against many types of pathogens; respond quickly
• Include species resistance, mechanical barriers, chemical barriers, natural killer cells, inflammation, phagocytosis, and fever
• Adaptive (specific) defenses or immunity:
• Respond against only a specific type of pathogen; respond more slowly
• Accomplished by specialized lymphocytes, which secrete cytokines or antibodies
Humoral response and cellular response
A B cell may become activated and produce a clone of cells when it
encounters an antigen that matches its receptors, and binds to it
But most B cells need helper T cells for activation
When a helper T cell encounters a B cell that has already encountered
and bound to an antigen, the helper T cell releases cytokines that
activate the B cell, stimulating it to proliferate (divide and form a clone)
Some of the B cells differentiate into plasma cells, which produce and
secrete antibodies (immunoglobulins)
Antibodies travel through the body fluids to attack and destroy antigens;
this is called the humoral immune response
Purpose and examples of First, Second and Third line of defense
The second line of defense is managerial and is responsible for oversight of the doers. They also develop and implement risk management processes, policies and procedures.
It is the first or most important method to be used in dealing with a problem. Residents have the responsibility of being the first line of defense against wildfires.
The third line of defense is called the immune response and is specific. It involves the production of two types of lymphocytes (B and T cells) which are specific to the invading particle. They work together to attack the pathogen.
Artificial vs. Naturally acquired immunity
Naturally acquired active immunity occurs after exposure to the
antigen; long-term resistance results, due to the events of a primary
immune response (memory B cells are produced)
Artificially acquired active immunity occurs through the use of vaccines,
without the person becoming ill from the disease; since vaccines contain
weakened or dead pathogens, person develops long-term immunity, due
to an immune response that includes memory B cell formation
Naturally acquired passive immunity occurs as antibodies are passed
from mother to fetus; this is short-term immunity, due to lack of an
immune response and lack of memory B cell formation
Artificially acquired passive immunity involves the injection of gamma
globulins containing antibodies or antiserum; this is short-term, because
there was no antigen exposure, no immune response, and no memory B
cells produced
Spleen:
• Lies in the upper left abdominal cavity
• Largest lymphatic organ in body
• Similar to a large lymph node, except it contains blood instead of lymph
• Filters the blood and removes damaged blood cells and bacteria
Thymus:
• Shrinks in size during the lifetime; large in children, small in adults, replaced by adipose & connective tissue in the elderly
• Lobules contain lymphocytes, some of which mature into T cells
T Cells and the Cellular Immune Response
Types of T cells:
• Helper T cells stimulate B cells to produce antibodies against
the displayed antigen
• Cytotoxic T cells monitor the body's cells, recognizing and
eliminating cancer cells and virus-infected cells
Types of T cells:
Lymphocytes require activation before they can respond to antigens
T cell activation requires an encounter with an antigen-presenting
cell (accessory cell, APC), such as a B cell or macrophage, that has
already encountered and phagocytized the antigen
Antigens and antibodies
which are usually large and complex foreign molecules
• Immune response is directed against “nonself” molecules,
• Before birth, the body makes an inventory of “self” antigens
response (ex: proteins, food, chemicals, etc...)
• Can be any large molecules that that can trigger an immune
Antigens:
Antibody Actions
3 methods by which antibodies react to antigens:
• Direct attack by agglutination, precipitation, or neutralization of
antigens; these methods make antigens more susceptible to
phagocytosis
• Activation of complement results in opsonization, chemotaxis,
inflammation, agglutination, neutralization, alteration, or lysis
of antigens or antigen-bearing cells
• Inflammation: Stimulation of local inflammatory changes in the
area, that helps prevent the spread of the pathogens