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Lymph/Immune System Ashley Duenas P:3 - Coggle Diagram
Lymph/Immune System Ashley Duenas P:3
Major Functions:
Lymphatic System:
~Protecting body from illness causing invaders.
~Drains excess fluid from tissue.
~Returns clean fluids and leaked proteins back to the blood.
Immune System:
~to fight disease-causing germs (pathogens) like bacteria, viruses, parasites or fungi, and to remove them from the body,
~to recognize and neutralize harmful substances from the environment
~to fight disease-causing changes in the body, such as cancer cells.
Antigens/Antibodies
Antibodies:
Soluble proteins secreted by plasma cells that are derived from
B-cells
.
~Carried by body fluids.
~Capable of binding to specifically to antigens.
~5 Types: IgG, IgA, IgM, IgD and IgE
Antigens:
Proteins, polysaccharides, glycoproteins, glycolipids that can
trigger an immune response.
~Can be the entire
pathogen
or only part of it.
~Basically can be
anything
that can trigger an immune response.
*
Before birth, the body makes an inventory of "self" proteins and other large molecules.
Chemokines:
released by infected cells to start an immune response.
Cytokines:
molecules that signal cells in order to communicate and start an immune response.
Antibody Actions:
Opsonization
: Some act as labels to be identified by other immune cells for phagocytosis.
Neutralization:
Some work as antitoxins, blocking the effects of poison produced by certain bacteria.
Complement Fixation:
Occurs when complement proteins attach to antigens/foreign substances such as bacteria and activate immunity,
Agglutination:
Some clump with other antibodies to form clots in the blood (used for blood typing).
Precipitation:
antigen-antibody complex becomes so large, it is insoluble and less likely to spread.
Cells involved
Helper T-cells:
Specialized lymphocytes that help other T and B-cells to perform their functions.
Nuetrophils:
Engulf smaller particles
Monocytes/Macrophages:
Give rise to macrophages which become fixed in various tissue and engulf larger particles.
Cytotoxic T-cells:
These lymphocytes mature in the Thymus and kill infected cells.
Plasma Cells:
Cells develop from B-cells and make immunoglobulin for the serum and secretions.
B-Cells:
These lymphocytes arise in the bone marrow and differentiate into plasma cells and memory cells.
T-cells:
directly attack cells infected with viruses, and they also act as regulators of the immune system. Differentiating into helper and memory T-cells for future responses.
Natural Killer:
Derived from bone marrow and easily killed infected cells with viruses.
Adaptive Responses:
Humoral Response:
Mainly B-Cells
1.
A
B-cell
becomes activated and produces a clone of cells when it encounters its matching antigen, however, most B-cells need helper T-cells for activation.
2.
When a B-cell encounters an antigen itself,
helper T-cells
release cytokines that activate the B-cell so that it can divide.
3.
Then some of the of the B-cells become
plasma cells
, that produce/secrete antibodies, while others become
memory B-cells
that will respond to future encounters with that antigen.
Cell-Mediated Response:
Mainly T-Cells
1.
T-cell activation requires the presence of
antigen-presenting cells
such as B-cells or macrophages that have already encountered the antigen.
2.
The antigen-presenting cell must display its
Major histocompatibility complex
proteins. If the antigen fits the T-cell's antigen receptor than it activates.
3.
The activated T-cells then interact directly with antigen-bearing cells. Also synthesizing and secreting
cytokines
that enhance the response.
4.
Helper T-cells
than stimulate B-cells to produce antibodies for the antigen. While
Cytotoxin T-cells
monitor the body's cells, recognizing and eliminating tumor/virus infected cells.
5.
Lastly,
memory T-cells
are also produced in order for a no-delay response in the future when exposed to the same antigen.
Immune Defenses
Innate (non specific) defenses:
~Body's 1st line of defense.
~Mechanical Barriers:
Unbroken skin and mucous membranes of the body create mechanical barriers the prevent the entry of certain pathogens.
~Body's 2nd line of defense.
~2nd line of defense:
~Inflammation:
Tissue response to a pathogen
~Characterized by
redness, swelling, heat and pain.
~Major actions: dilation of blood cells, inclease of blood volume and invasion of white blood cells.
~Phagocytosis:
Neutrophils and monocytes leave the blood stream at areas of injury because they are attracted to the injured area.
~Remove foreign particles from the lymph.
~Fever:
Offers powerful protection against infection by interfering with the proper conditions that promote bacterial growth
~Chemical barriers:
Highly acidic and caustic environment provided by the gastric juice or lysozyme in tears; kills many pathogens.
Natural Killer cells:
Type of lymphocyte that defends the body against various viruses and cancer cells.
~Secretes cytolytic substance known as
perforin
and chemicals that enhance inflammation.
Adaptive (specific) defenses:
~Body's 3rd line of defense.
~The response mounted by the body against
specific
recognized foreign molecules.
~This is when the pathogen has entered and has contact with the body.
~2 types
: Humoral
and
Cell-mediated
Response
Cell Mediated
: Involves
T-cells
~T-cell activation by an antigen presenting cell (macrophages that has encountered)
~MHC: Major Histocompatibility complex: help the immune system recognize foreign substances.
Humoral
: Involves
B-cells
~Activated by helper T-cells or by encountering a matching antigen.
~Some become
plasma cells
(antibodies) while others become
memory cells.
When B or T-cells become activated for the first time, their actions constitute a
primary immune response
, after which cells remain as memory cells.
If the same antigen is encountered again, memory cells can mount a more rapid and generall long-lasting response called the
secondary immune response
.
Anatomy of Lymphatic System:
Thymus:
Located behind sternum above the heart.
~Lobules contain lymphocytes some of which mature into
T-lymphocytes
that leave the thymus to provide immunity.
~Secretes hormones called
Thymosin
, which regulate T-lymphocyte development.
Lymph Nodes:
Located along lymphatic vessels.
~Contain
lymphocytes
and
macrophages
which clean the lymph as it flows through the node.
~Bean-shaped with blood vessels, nerves and efferent lymphatic vessels attached.
~Function:
Filter lymph and
remove bacteria and cellular debris
before lymph is returned to the blood.
Bone Marrow:
Site of blood cells and immature lymphocyte formation as well as
B lymphocytes
maturation.
Spleen:
Lies in the upper left abdominal cavity and is the largest lymphatic organ.
~Resembles a large lymph node except that it contains blood instead of lymph.
~ Composed of
white pulp
( many lymphocytes) and
red pulp
( red blood cells, macrophages and lymphocytes).
~Function:
Filters
the blood and
removes
damaged blood cells and bacteria.
Tonsils:
Composed of 3 masses of lymphoid tissue around the openings of the mouth and throat.
A.k.a:
Palatine, Pharyngeal
and
Lingual Tonsils
.
~Subject to chronic infection like the enlargement of pharyngeal tonsils.
Lymphatic Vessels:
Collect and carry away excess fluid from interstitial spaces and special vessels called lacteals.
~Lacteals transport fats to the circulatory system.
~1 way
Disorders
Endema:
A condition that interferes with the flow in lymph since the fluids are not returned to the vascular system but instead accumulate in the tissue.
Tonsils:
The enlargement of pharyngeal tonsils may impair breathing. Tonsils are composed of 3 masses of lymphoid tissue around the opening of the mouth and throat.
~A.k.a: Palatine, Pharyngeal and lingual tonsils.
HIV: is a Human Immunodeficiency Virus
~The virus eventually kills more and more cells in the immune system, making it lose the ability to fight off common infections.
~
AIDS
is the final stage of this virus after being infect sexually or unclean needle.
