2. Clare Hargreaves-Norris
Introduction
The lymphatic system is the secondary circulatory
system that drains away tissue fluids and waste
products and filters the lymph protecting against
infection. It is a one way drainage system that drains
excess tissue fluid and transports it back into the
venous system of the blood supply. It also returns to
the blood any large protein molecules that were unable
to pass back through the capillary walls. Unlike the
circulatory system, the lymphatic system does not have
a heart to pump it around the body; instead its onward
movement is assisted by the pumping action of the
muscles that surround the lymph vessels, the position
of valves to prevent backflow and the negative pressure
created in the thorax during inspiration.
3. Clare Hargreaves-Norris
Functions of the lymphatic system
The lymphatic system:
Filters bacteria, foreign materials, toxins and any harmful
materials.
Drains away excess fluid to prevent water clogging of the
tissues and cells.
Transports proteins back into the blood supply.
Produces lymphocytes which protect and defend the body
against infection.
Produces antibodies to fight bacteria.
Absorbs fat from the intestine and transport it to the liver.
4. Clare Hargreaves-Norris
Did you know?
When the body is ill with an infection, your
glands swell up. Many of these glands are lymph
nodes. When you are healthy they are about the
size of a pea or grape, but during illness they can
be as big as golf balls.
Lymph nodes contain billions of white cells,
multiplying rapidly to fight the invading germs.
During illness they fill with millions of extra white
cells and also dead germs.
5. Clare Hargreaves-Norris
Structures of the lymphatic system
The lymphatic system is comprised of:
Lymph fluid
Lymph capillaries
Lymph vessels
Lymph nodes
Lymph ducts
Spleen
6. Clare Hargreaves-Norris
Lymph fluid
Lymph fluid is a transparent, colourless, watery fluid that is
similar to blood plasma, however contains more waste
products and fewer nutrients. Lymph usually contains the
larger particles that could not re-enter the blood supply.
Lymph is made up of:
Plasma (watery substance)
Proteins
Waste products and toxins
Fats
Urea
Gases
Lymphocytes
7. Clare Hargreaves-Norris
Lymph capillaries
Lymph capillaries are fine,
hollow elastic tubes which are
similar to blood capillaries in
structure, however, they are
wider. The cell walls are made
from a single layer of epithelial
tissue and are more permeable
than blood capillaries,
therefore allowing larger
substances to pass through
their walls. Lymph capillaries
are blind ended and transport
the lymphatic fluid away from
the cells and tissues.
8. Clare Hargreaves-Norris
Lymph vessels
These larger vessels run closely
alongside veins and transport
the lymphatic fluid through one
or more sets of lymph nodes.
They have collapsible walls,
carry lymph at a steady
pressure, and are similar to
veins in structure, as they
contain valves called semi lunar
valves. The lymph enters the
node through the afferent
vessel and leaves through the
efferent vessel.
9. Clare Hargreaves-Norris
Lymph nodes
Lymph nodes are tiny clusters of
glands, which filter out bacteria
and toxins, therefore, protecting
the body against infection.
Lymphocytes, macrophages and
phagocytes are numerous here;
these white blood cells produce
antibodies and ingest bacteria
and foreign materials to fight
against infection. When a person
is suffering from an infection
the lymph nodes swell and
become tender, as the white
blood cells fight the infection.
10. Clare Hargreaves-Norris
Lymph ducts
The lymph ducts are the
vessels that allow the
collected tissue fluid to
return back into the blood
stream. The right lymphatic
duct drains lymph from the
right side of the head, neck,
chest and right arm, the
thoracic duct drains from the
left side of the head and
neck, left arm, left side of
chest area and both legs.
Area drained by right
lymphatic duct
Area drained by thoracic
duct
11. Clare Hargreaves-Norris
The spleen
The spleen is situated
behind the stomach
and is responsible for
producing antibodies
and lymphocytes, and
destroying old red
blood cells.
15. Clare Hargreaves-Norris
Lymph Nodes
Node Location Function
Buccal nodes Face, cheek region Drains the eyelids, nose and
the facial skin
Parotid nodes In the face, in
front of the ear
Drains the eyelids, nose and
ears
Posterior
auricular nodes
Behind the ear Drains behind the ear and
temple
Occipital
nodes
Back of head Drains the back of the scalp
and the upper neck region
Submental
nodes
Under the chin Drains lower lip, chin and the
floor of the mouth
Submandibular
nodes
Under the jaw line Drains the chin, lips, nose,
cheeks and tongue
Superficial
cervical nodes
In the neck, below
the ear
Drains lower part of ear,
parotid area and neck
Deep cervical
nodes
In the neck Drains the back of the scalp
and neck
16. Clare Hargreaves-Norris
Lymph Nodes
Node Location Function
Axillary nodes In the underarms Drains the pectoral area and
the upper arm
Supratrochlear
lymph nodes
In the elbow Drains the fingers, thumb,
hand and forearm
Intestinal lymph
nodes
Inside the abdominal
cavity
Drain abdominal viscera
Iliac nodes Hip area Drains the pelvic area
including reproductive
organs and the bladder
Inguinal nodes In the groin Drains the pelvic area & legs
Popliteal nodes Behind the knees Drains the toes, feet and
lower legs
Cisterna chyli Sack like chamber in
the abdomen
Receives lymph from the
lower abdomen, lower limbs,
and pelvis and conveys it into
the thoracic duct
17. Clare Hargreaves-Norris
Interaction between blood and lymph
The blood and lymph supply work closely alongside each
other and interact at numerous points:
Primary interaction occurs within capillary exchange.
Small lymph vessels run alongside the arteries and veins
collecting lymph from tissues.
Lymph vessels transport lymph fluid to the lymph nodes for
filtering, thereby preventing foreign substances entering
the blood stream.
Production of fresh lymphocytes are activated which
circulate around the body in both lymph and blood vessels.
Lymph transports fat from the digestive tract to the blood.
Lymph returns to the blood supply via the lymphatic ducts
and into the subclavian veins.
18. Clare Hargreaves-Norris
Diagram to illustrate the interaction
between the blood and lymph
Arteriole
Red
blood
cells
Blood capillary
with semi
permeable walls
Venule
Tissue fluid
bathing cells and
tissues
Lymph
fluid
Cells and
tissues
Lymph capillary with
semi permeable walls
19. Clare Hargreaves-Norris
Factors affecting lymphatic drainage
General blood circulation - a good strong
circulation ensures that the flow of tissue
fluid into the lymph vessels is maintained.
Exercise - the action of the muscles
speeds up the movement of lymph through
the vessels.
Massage - enhances the drainage by
forcing the movement of lymph through
the vessels.