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Introduction by Period 7, 2014
The four parts of the lympatic system include the
vessels, fluid, Lyphocytes and the Lymphoid tissues and
organs.
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•
The vessels: the lymphatic vessels begin in the peripheal tissues and end at the
connectrions to the veins, they are also called lymphatics.
•
Fluid: the fluid called lymph looks like plasma but it contains lower concentration
of suspended proteins. this fluid flows through the lyphatic vessels.
•
Lymphocytes: Lymphocytes are specialized cells that preform special functions to
defend the body.
•
Lyphoid tissues and organs: lyphoid tissues an example is the tonsils;are a group of
loose connective tissue and lymphocytes in stuctures called lymphoid nodules.
Lymphoid organs the examples include lymph nodes, sleen, and thymus; are more
complex containing more lymphocytes and they are connected to lymphatic
vessels.
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Production, maintenance, &
distribution of lymphocytes
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• Lymphocytes react to bacteria and viruses
(invading pathogens), abnormal body cells,
and foreign proteins. They attempt to
eliminate them.
Return of fluid and solutes from
peripheral tissue to the blood
• Maintains normal blood volume and eliminates local
variations in the composition of the interstitial fluid.
A break in the Lymphatic vessel can cause a fatal
decline in blood volume.
Jacqueline Williams & Kaylee Hayes 2
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Distribution of hormones, nutrients, &
waste products from their tissues of
origin to the general circulation
• Helps substances that are unable to enter the
blood stream directly can do so by way of the
Lymphatic vessels.
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Lymphatic Vessels
• Lymphatic vessels carry lymph from peripheral
tissues to the venous system.
• Lymphatic capillaries begin as blind pockets in
peripheral tissue and are lined by simple
squamous tissue.
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Lymphatic vessels
• The lymphatic vessels empty into two large collecting
structures called lymphatic ducts.
• The thoracic duct collects lymph from the lower abdomen,
pelvis, and lower limbs, and from the left half of the head,
neck, and chest.
• It empties its collected lymph into the venous system near the
junction between the left internal jugular vein and the left
subclavian vein.
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Lymphatic vessels
• The smaller right lymphatic duct delivers
lymph from the right side of the body
above the diaphragm.
• It empties into the right subclavian vein.
• Blockage of the lymphatic drainage is
known as a condition called
lymphedema.
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Lymphocytes
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A cell of the lymphoid system that participates in immune
response. Lymphocytes account for roughly 25%of the
circulating white blood cell population. The three types include
T-Cells, B-Cells, and NK Cells.
T-Cells and B-Cells
• T-cells or thymus-dependent cells are lymphocytes responsible
for cellular immunity and for the coordination and regulation
of the immune response. Cytotoxic T Cells directly attack
foreign cells or virus infected body cells.
• B-cells or bone-marrow cells are lymphocytes capable of
differentiating into the plasma cells that produce antibodies.
Antibodies bind to specific chemical targets called antigens,
which are usually pathogens.
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NK Cells
• NK cells or natural killer cells are lymphocytes that
attack foreign cells, normal cells infected with
viruses, and cancer cells that appear in normal
tissues.
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Lymph Nodules –
Lymph nodules are masses of lymphoid
tissue that are not surrounded by a
fibrous capsule.
Structure and Location
• -Lymph Nodules are found beneath the
epithelial lining various organs of the
respiratory, digestive, and urinary systems.
• -There are different types of lymph nodules
such as the tonsils, which guard the entrance
of the digestive and respiratory tracts.
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Infections and Description
• -Nodules are open to the external environment,
the provide a root of entrance to the body to
potential dangerous toxins and organisms.
• -The lymphocytes in a lymphoid nodule are not
always able to destroy bacterial or viral invaders,
and if pathogens establish in a lymph nodule, a
inflammatory response begins.
• -There are two main infections that happen from
the nodules called tonsilitis and appendicitis.
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Lymphoid Organ : Nodes
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Lymph Nodes are small oval organs that
filter and purify the lymph before it
reaches the venous system.
They are located in
regions where they
detect harmful
intruders before
reaching vital organs.
Group 6
Lymphoid Organ : Thymus
The Thymus is a pink gland
posterior to the sternum that
produces T- Cells and maturation.
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Lymphoid Organ : Spleen
The spleen filters blood and
removes abnormal cells and
initiates cells to antigens in blood.
The spleen also
stores iron from
recycled RBC’s.
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Autoimmune disorders develop when the immune
response mistakenly targets normal body cells and
tissues.
Autoantibodies-misguided antibodies that attack
normal body cells and tissues
Examples of autoimmune disorder:
• Rheumatoid arthritis
• Insulin-dependent diabetes mellitus (IDDM)
Many autoimmune disorders appear to be cases of
mistaken identity.
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Immunodeficiency Disease is when the immune system fails to develop normaly or the 7
immune response is blocked in some way.
Severe combined immunodeficiency disease- fails to develop either cell
or antibody-mediated immunity.
Example of Immunodeficiency is AIDS
AIDS- a result of a viral infection that targets primarily helper T cells.
Allergies
Type I- immediate hypersensitivity- The
reaction may involve skin, eyes,
nasopharynx, bronchopulmonary tissues
and gastrointestinal tract. The reaction
may cause a range of symptoms from
minor inconvenience to death. The
reaction usually takes 15 - 30 minutes from
the time of exposure to the antigen
Type II- cytotoxic reactions- The antigens
are normally endogenous, although
exogenous chemicals which can attach to
cell membranes can also lead to type II
hypersensitivity. Drug-induced hemolytic
anemia, granulocytopenia and
thrombocytopenia are such examples. The
reaction time is minutes to hours.
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Allergies
Type III- immune complex disorders- The
reaction may be general or may involve
individual organs including skin, kidneys,
lungs, blood vessels, joints or other
organs. This reaction may be the
pathogenic mechanism of diseases
caused by many microorganisms. The
reaction may take 3 - 10 hours after
exposure to the antigen
Type IV- delayed hypersensitivity- The
classical example of this hypersensitivity is
tuberculin reaction which peaks 48 hours
after the injection of antigen. The lesion is
characterized by induration and
erythema.
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