Lymphatic System
A&P Chapter 15
Pg 461
Introduction
Consists of : lymph, lymph
vessels, lymph nodes, and lymph
tissue
Lymph
Thin watery fluid
Made of interstitial, or
intercellular fluid that forms
when plasma diffuses into tissue
spaces.
Composed of water, digested
nutrients, salts, hormones, CO2,
lymphocytes, and metabolic
waste
Lymphatic Vessels
Located throughout the body
Lymphatic capillaries: small
saclike open-ended vessels;
acts like drainpipes; picks up
lymph at tissues throughout
the body; capillaries joint
together to form larger
lymphatic vessels
Lymphatic vessels carry lymph
Skeletal muscle contraction
causes lymph flow
Lymphatic Vessels cont’
Vessels pass through lymph
nodes
Contain valves that keep
lymph flowing in one direction
Specialized lymphatic
capillaries (lacteals) are
located in the small intestine
– Pick up digested fats or lipids
– Lymph is mixed with lipids =
chyle
– Lacteals transport chyle to the
bloodstream
Lymph Nodes
Popularly called “glands”
Located all over the body, usually
in small clusters
Small round masses ranging in
size from a pinhead to an almond
Lymph vessels bring lymph to
the nodes
Lymph Nodes
Nodes filter out impurities such
as:
–Carbon
–Cancer cells
–Pathogens
–Dead blood cells
Lymphatic tissue in nodes also
produce lymphocytes: (a type
of leukocyte= WBC), and
antibodies (substances that
fight infection)
Lymph Nodes
Purified lymph, with
lymphocytes and antibodies
added leaves the lymph node
by a single lymphatic vessel
Lymphatic Ducts
As lymphatic vessels leave
the lymph nodes, they
continue to join together to
form larger lymph vessels
Eventually they drain into
one of two lymphatic ducts:
Right or the Thoracic
Lymphatic Ducts
Right Duct:
–Short tube
–Receives all the purified
lymph form the right side
of the neck and head, the
right chest, and the right
arm
Lymphatic Ducts
Thoracic Duct:
Much larger tube
Drains lymph from the rest
of the body
Empties into the R
Subclavian Vein, returning
purified lymph to the blood
Lymphatic Ducts
Thoracic Duct cont’
Enlarged pouchlike structure
called the cisterna chyli is
located at the start of the
thoracic duct and serves as
storage area for purified lymph
Lymph Tissue
Located throughout the body in
addition to being in lymph nodes
Tonsils, spleen, and thymus are
examples of lymphatic tissue
Tonsils: Masses of lymph tissue;
filter interstitial fluid; 3 pairs of
tonsils= palantine, pharngeal
(adenoids), and lingual
Lymph Tissue
Spleen
Organ located on L side in back
of the upper part of the stomach
Produces leukocytes and
antibodies
Destroys old RBC’s; Stores RBC’s
Destroys thrombocytes,
Filters some metabolites and
wastes from tissue
Lymph Tissue
Thymus
Mass of lymph tissue
located in the center of the
upper chest
Atrophies or wastes away
after puberty and is
replaced by fat and
connective tissue
Lymph Tissue
Functions during early life by
producing antibodies and
manufacturing lymphocytes
to fight infection
Function is taken over by
lymph nodes after it
atrophies