Lymphatic drainage massage
Lymph drainage is a special type of
massage of the lymph vessels. It is not a treatment of the muscles and
articulations, but rather a treatment of the connective tissues and the
tissue fluids within the body. Manual lymphatic drainage differs from
conventional massage techniques because it not only stimulates the removal
of waste products, but also it clears the congested lymph ducts in such a
way that the fluid carrying the vital nutrients to the cells of the body is
able to flow more effectively.
Evidence suggests that good health depends
on the circulation of lymph, and that cells are damaged if the lymph flow is
obstructed or reduced. However, in order to apply the technique of lymphatic
drainage, it is essential to have an understanding of how the lymphatic
system functions. Therefore this module is concerned with the lymph-vascular
system, and the lymphoid organs. The first part of the module outlines the
roles of the lymph-vascular system: the formation of lymph, and the flow of
lymph. This is followed by a description of the lymphoid organs. Finally in
the module is a description of the technique of lymph drainage of the legs
and arms.
The lymph-vascular system
You should be able to recall from an
earlier module that cells are surrounded by extracellular tissue fluid which
is derived from the bloodstream. Water, and dissolved substances such as
oxygen and nutrients, constantly are filtering through capillary walls into
the spaces between the cells, adding to the volume of tissue fluid in this
region. Under normal conditions this fluid is removed at a steady rate so
that it does not accumulate around the cells. While fluid is transported to
the tissues of the body by the circulatory system, the vessels of the
lymph-vascular system assist in returning this fluid to the bloodstream.
The lymph-vascular system is a second
circulatory system in the body. It contains capillaries which empty into
increasingly larger vessels. These lymphatic vessels transport lymph, a
tissue fluid that resembles blood plasma in its composition. While the
circulatory system contains about 5 litres of red blood, the lymph-vascular
system contains approximately 50 to 60 litres of lymph fluid.
Along the route of the lymph vessels are
numerous clusters of specialised cells called lymph nodes. Lymph nodes are
strategically placed around the whole body to act as filters, preventing
harmful substances or pathogens from entering the body tissues. Those
systems most prone to invasion by foreign organisms are those which are
richest in lymphatic vessels. Therefore the greatest numbers of lymph nodes
are found in the region of the upper alimentary canal, and groin.
Role of the lymph-vascular system
The lymph-vascular system helps to
maintain an appropriate environment around cells by assisting in the
maintenance of the water and protein balance in the tissues. Most tissue
fluid formed at the arterial ends of capillaries, along with some of the end
products of cellular respiration, including carbon dioxide, returns to the
circulation through the venous ends of capillaries by diffusion. The
remaining tissue fluid (about 10–20%) passes into blind-ending lymphatic
capillaries of the lymph-vascular system. It then travels through a series
of lymph nodes to be cleared of toxins before reaching the major collecting
ducts. Once this tissue fluid reaches these ducts, it is then returned to
the venous part of the blood circulation. As the lymph passes through the
lymph nodes it is cleared of foreign chemicals and invading microorganisms.
A further protective role of the lymph-vascular system is its production of
lymphocytes, cells which are important in the immune system of the body.
These lymphocytes are the lymphoid leukocytes.
If for some reason there is an obstruction
of the lymph vessels or the flow of lymph is interrupted, lymphatic drainage
of an area cannot continue. This causes the area to swell with fluid
containing protein, resulting in oedema. In cases of fluid build up, oedema,
or the formation of cellulite, lymphatic massage can help to drain away the
accumulated fluid. In fact, for the treatment of cellulite the results of
lymphatic drainage are rapid and effective.
When applying lymph drainage, it is
important to drain towards the natural flow of lymph to encourage the flow
of lymph through the nodes to the terminal ducts.
Lymph formation
Formed from the extracellular fluid, lymph
not only depends upon the filtration of fluid and materials from the blood
capillaries, but also on the formation and secretion of products by the
cells. Therefore, lymph contains those substances which can escape from the
capillaries, as well as those chemicals which are produced by the cells and
which pass from them into the surrounding fluid.
Lymph contains proteins. While only the
smaller proteins escape from the capillaries, some are transported out of
the cells into the extracellular fluid. The lymph is responsible for
returning these valuable proteins to the circulation. Lymph contains very
little oxygen, as most of this dissolved gas is removed by the cells before
the fluid reaches the lymph capillaries. Many other nutrients are found in
relatively low levels in the lymph. The small inorganic ions normally found
in the plasma, ions such as sodium, potassium, chloride, calcium, magnesium,
and so on, are found in the lymph. These small ions readily cross membranes
of any type and have no trouble entering the lymphatic vessels. Glucose also
readily enters the lymph, particularly in the area of the digestive system,
where after a meal there is a high concentration of these small carbohydrate
molecules.
The lymph draining the intestines is rich
in lipids which generally are too large to enter the blood by any other
route. The lymphatic vessels allow quite large molecules to cross their
membranes. This accounts for the presence in lymph of some large hormone
molecules secreted by certain cells. They enter the blood only after first
being taken up into the lymphatic capillaries.
The composition of lymph is variable,
being dependent on the source of the fluid as well as on other conditions.
Normally, lymph from most tissues is clear and colourless, but that from the
small intestine appears milky due to the presence of fat globules on their
way to be deposited into the blood. The fat globules are called
chylomicrons. That lymph which is derived from the liver has a high protein
content compared with lymph from other parts of the body. And lymph draining
from the lymphoid organs has a large number of lymphocytes.
While red blood cells are not normally
found in lymph, white cells are. Some of these leukocytes are able to
migrate from the interstitial fluid into the lymphatic vessels where they
help to protect the organism against foreign bodies and microorganisms.
The lymph-vascular system
Lacteals, which are the lymphatic
capillaries in the intestines, collect fluid from the extracellular space.
They merge to form larger and larger lymph vessels. The greater the diameter
of the lymphatic vessel, the lower is the permeability of its wall, which
means that the larger lymph vessels are only conveyors of fluid and do not
allow fluid to enter or leave. Flow through these vessels is aided by
internal valves which prevent any backflow of the lymph. These valves
operate in a similar manner to those of veins, although the valves are more
numerous in lymphatic vessels. The walls of the lymphatic ducts also are
similar to those of veins, although they are thinner.
At intervals along the lymphatic vessels
the fluid passes through structures called lymph nodes. The lymph vessel
which enters a lymph nodes is called an afferent vessel. An efferent vessel
carries the cleaned lymph fluid away from the node.
The larger lymphatic vessels, known as
lymphatic trunks, eventually empty their contents into two major ducts: the
thoracic duct, also called the left lymphatic duct, and the right lymphatic
duct.
Right lymphatic duct
The right lymphatic duct drains lymph from
the right upper arm and the right side of the head and thorax. It is about
one cm in length. It empties its contents into the right subclavian vein in
the upper right chest region.
Thoracic duct
The thoracic duct receives lymph from the
rest of the body not drained by the right lymphatic duct. At about 40 cm in
length, this duct is the larger of the two, and carries by far the greater
volume of lymph.
It empties its contents into the left
subclavian vein in the upper left chest, allowing the lymph to mix with the
rest of the circulatory system.
The thoracic duct arises from a large sac,
or reservoir, called the cisterna chyli in the abdomen. This sac extends
from the lumbar vertebrae to the base of the neck.
Lymph flow
Several factors aid the movement of lymph.
As was mentioned earlier, the vessels contain valves which control the flow
of lymph and stop any backflow. However, unlike the circulatory system these
vessels are not driven by a pump. Instead, the movement of fluid occurs by a
combination of osmotic pressure, and squeezing by normal activity of the
muscles.
Lymphatic fluid is propelled by
contraction of adjacent skeletal muscles or, in larger vessels, by smooth
muscle cells that force the fluid from one level to another, past the valves
that permit the passage of fluid in one direction only. Respiratory
movements, and a negative blood pressure in the veins into which the lymph
drains, also promote lymph flow. Each hour approximately 100 millilitres of
lymph flow through the thoracic duct, and another 20 millilitres flow into
the circulation by way of other channels. These figures are for a resting
individual.
Generally, lymph travels through a series
of nodes before reaching the major collecting ducts. However, there are
exceptions, such as the lymph vessels of the thyroid gland and the
oesophagus, and some of those around the liver. These lymph vessels drain
directly to the thoracic duct without passing through lymph nodes.
Lymph flows rather slowly. Therefore,
while sleeping, it is partly stopped. Overexertion, nervous tension, cold,
and fatigue cause it to slow down even more. Lymph circulation slows down
when the waste products accumulate and the lymph becomes viscous. The
stagnant lymph exerts a pressure, producing a feeling of pain in the tissues
and extremities. It also produces a feeling of fatigue and a heavy feeling
in the limbs. Puffiness and congestion can be particularly noticeable on
arising in the morning because the lymphatic fluid flows more slowly during
sleep.
The circulation of lymph can be promoted
by exercise, brisk rubbing, massage, and especially by deep breathing.
Lymphatic drainage is beneficial because
it helps to promote fluid movement, and pass lymph through the filtering
lymph nodes.
Lymphoid organs
The lymphatic system consists of central
and peripheral lymphoid structures. The structures that constitute the
central lymphoid group are bone marrow and the thymus gland.
The lymph nodes, spleen, tonsils,
intestinal lymphoid tissue called Peyer’s patches, and collections of other
lymphoid cells constitute the peripheral lymphoid group.
Lymph nodes
There are approximately 400-450 lymph
nodes in a normal young adult body. In the head and neck region there are
60-70 nodes, about 30 are found in the arm and the superficial thoracic and
abdominal walls, the legs and superficial buttock have about 20 nodes, in
the thorax there are some 100 nodes, while the rest are found in the abdomen
and pelvis.
Lymph nodes are located along lymph
vessels and serve as filters. They form chains along the major arteries to
the abdomen and pelvis, and tend to occur in groups. The superficial groups
include the cervical, cubital, popliteal, and inguinal nodes, while the deep
groups include the iliac, axillary, thoracic, lumbar, intestinal,
mesenteric, and portal nodes. The lymph draining the lower parts of the body
is filtered through the inguinal and iliac node clusters. The intestinal
nodes (Peyer’s patches) serve as the filter for the lymph which is derived
from the gastrointestinal tract. The lymph from the arms passes through the
axillary nodes in the armpits. And that derived from the mouth and facial
region filters through the submaxillary nodes.
Lymph nodes are flattened, round or ovoid
shaped bodies, ranging from 1mm to 25mm in length. The node itself is
covered with a fibrous capsule and divided internally into open
compartments.
Within the node are sites for lymphocyte
production, which is important for the function of the immune system. In the
middle of a lymph node, an area called the medulla, lymphocytes are arranged
in strands. Phagocytic macrophages and plasma cells, cells which have the
capacity to destroy bacteria and foreign substances, are also contained in
the lymph nodes.
Afferent vessels entering the node empty
their fluid into the medulla of the node where it percolates through the
node until it exits through the efferent lymphatic vessel. While passing
through the node, the fluid comes into contact with the phagocytic and other
cells which do the actual filtration.
As part of their filtering process the
lymph nodes may trap cancer cells. Therefore the lymph nodes help to resist
the spread of cancers. Specialists in this field are interested in looking
at the lymph nodes draining a region where there is a cancer to determine
whether the cancer has spread to other parts of the body. The presence of
cancer cells in the draining lymph nodes indicates that the cancer already
has started to spread to distant sites. If this has occurred, an
aromatherapy treatment must not be carried out.
Thymus
The thymus is an elongated, flat, double
lobed structure located in the neck below the thyroid gland. It extends into
the upper part of the thorax posterior to the manubrium of the sternum. At
birth, it is fully developed and weighs about 15–20g. At puberty it reaches
about 40g in weight, and after puberty it gradually involutes, being
replaced by fatty connective tissue.
The thymus of the newborn produces
hormones that control the development of lymphoid organs during infancy. The
primary function of the thymus is to produce T-lymphocytes which play a key
role in the immune system.
Lymphatic drainage: breast
The lymphatic drainage of the breast is
extensive. Glandular substance of the breast is drained by lymphatic vessels
around the lactiferous ducts. The vessels that run between the lobules and
lobes drain superficially to a lymph node plexus around the nipple, and more
deeply to a plexus in the fascia of the muscles that cover the chest wall.
Lymph streams from the breast to the regional nodes.
Most lymph vessels draining the breast
pass through the pectoral nodes to the axillary nodes, although some lymph
does drain to the internal thoracic nodes within the chest. Some lymph
drains to the abdominal region from the breast.
The drainage of lymph from the breast is
important since it is along the lymph vessels that breast cancer cells can
spread. Most commonly they spread firstly to the nodes in the armpit, which
is why these are examined for evidence of metastases when a woman is
operated on for breast cancer. The reason for the dominance of the
metastases in the axillary nodes is that this is where the majority of the
lymph from the breast drains to. However, as you should now realise, any of
the lymph ducts draining the breast can act as conduits for the cancer
cells.
Lymphatic drainage: thoracic walls
The superficial lymphatic vessels of the
thoracic wall run with veins and drain to the axillary nodes. Those
superficial to the back muscles drain into nodes below the scapula, called
the subscapular nodes. Those in the chest region drain towards the pectoral
nodes.
From the deeper tissues of the thoracic
walls, lymph vessels drain mainly to the parasternal, intercostal and
diaphragmatic lymphatic nodes. The parasternal nodes are at the anterior
ends of the spaces between the ribs, called the intercostal spaces.
Lymphatic drainage: thoracic
contents
Before entering the thoracic duct or the
right lymphatic duct, lymph from the thoracic organs travels through the
brachiocephalic, posterior mediastinal, or tracheobronchial nodes. The
brachiocephalic nodes are situated in the superior mediastinum, anterior to
the brachiocephalic veins and large arterial trunks. They drain the thymus,
thyroid glands, pericardium, heart and lateral diaphragmatic nodes.
Behind the pericardium, near the
oesophagus and the descending thoracic aorta, are the posterior mediastinal
nodes. They drain from the oesophagus, posterior pericardium, diaphragm,
lateral and posterior diaphragmatic nodes, and sometimes the left lobe of
the liver to the thoracic duct, although some do join the tracheobronchial
nodes.
The tracheobronchial nodes drain the lungs
and bronchi, thoracic trachea, heart and some efferents of the posterior
mediastinal nodes. Their efferent vessels ascend on the trachea and unite
with other lymph vessels draining the chest region.
Lymphatic drainage: lungs and
pleura
The groups of lymph nodes involved in
drainage of the lungs are: the pulmonary nodes within the lung, situated
mainly at bifurcations of larger bronchi; the bronchopulmonary (hilar) nodes
located in the pulmonary hilus at the site of entry of the main bronchi and
vessels; and the tracheobronchial nodes found in the angles between the
trachea and bronchi, and at the junction of the two main bronchi. The
tracheal group are alongside of and in front of the trachea throughout its
course.
Almost all the lymph from the lungs
eventually reaches the bronchopulmonary (hilar) lymph nodes, with or without
passing through pulmonary nodes on its way. Some lymph may bypass the hilus
and go directly to the tracheobronchial nodes.
