Anatomy Bowl Prep
The Lymphatic and Immune System by Zachary Hale
Know and understand these terms.
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The lymphatic system is our “safety net” also
known as our immune system.
It is composed of vessels that help maintain
fluid balance and lymphoid tissues that help
protect the internal environment
Understand how the different regions of the body
are drained.
 Understand the flow of lymph through lymph nodes
 Understand the role of lymph nodes in microbial
defense
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Lymph
 Fluid in the tissue spaces that carries protein molecules
and other substances back to the blood
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Lymph Nodes
 Bundles of cells along the lymphatic system that:
▪ Filters lymph
▪ Defends the body and houses WBC
▪ Has afferent and efferent vessels that allow lymph to flow in and
out in one direction

Lymphatic Vessels
 Permit only one way movement of lymph

Interstitial fluid
 Is the fluid that leaks out of the
capillaries and in between tissues

Right Lymphatic Duct
 Returns lymph to the heart from the
right arm, right upper chest, and right
side of the face

Thoracic Duct
 Lymph from ¾ of the body return via
the thoracic duct

Lacteals

Absorb fats from the villi of the small
intestine and carries it through the lymphatic
system

As lymph flows from its origin in the tissue spaces toward the
thoracic or right lymphatic ducts and then into the venous
blood it is filtered by moving through lymph nodes

Lymph nodes are used for:
 Biological filtration of the lymph and for defense
 Fluid enters through the afferent side and leaves via the efferent side
 Macrophages and WBC that reside in the lymph nodes filter and
sample the blood
▪ If a pathogen is found it enables body to respond quickly!
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Know the basic roles in immunity of the
different lymphatic organs: Thymus, Tonsils
(3 types), Spleen
Define and study the difference between:
 Nonspecific Immunity
 Specific Immunity

Thymus
 Small lymphoid organ located in the mediastinum
 Composed of lymphocytes in a unique epithelial meshwork
 Is the site for T-cell maturation
▪ A WBC vital for defense
▪ T-cells develop under the influence of the hormone thymosin

Tonsils
 Masses of lymphoid tissue
 Are located in a protective ring under the mucous membranes of the
mouth and back of the throat

Spleen
 Largest lymphoid organ
 Filters the blood

Specific immunity
 Includes protective mechanisms that confer very specific
protection against certain types of pathogens
 Involves memory and the ability to recognize and respond
to particularly harmful substances

Nonspecific immunity
 Is maintained by mechanisms that affect any irritant or
abnormal substance that threatens the body
 General protection!
Know how these proteins function to defend against invasion:

Antibodies

Complement

Antibody:

Complement proteins
 Protein compounds that are
 Is the name used to describe
normally present in the body
 They bind to antigens (may
be foreign proteins, most
often molecules on the
surface of things invading the
body)
14 proteins normally present
in an inactive state in the
blood
 Proteins are activated by
exposure of complementbinding sites to antibodies
 This results in the formation
of a highly specialized
antigen-antibody complex
that targets foreign cells for
destruction
Know the basic function of each of these cell types and where they are formed:

Phagocytes- cells that
use phagocytosis to ingest
foreign particles
 Neutrophils
 Monocytes
 Macrophages

Lymphocytes
 T-Lymphocytes
▪ Sensitized T cells- can kill
invading cells or recruit
macropahges
 B-Lymphocytes
▪ Immature B cells
▪ Activated B cells
▪ Plasma cells – send huge
amounts of antibodies into the
blood
▪ Memory cells – wait in lymph
nodes for second exposure to an
antigen

What is a disease process that attacks the
immune system directly and how?


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HIV
Is a virus that directly attacks the body
The virus invades T-cells
 Then uses the T-cell machinery to produce more
copies of the virus
 Eventually the T-cell is bombarded with new virus
molecules and explodes releasing more virus
molecules into the blood