Impact of Lymphatic Disorder and Associated Treatments
1.1 Introduction to the Lymphatic System
The lymphatic system is a network of organs, nodes and vessels that works in parallel to the
circulatory system, running through the whole body. The system is comprised of lymph
nodes, lymph vessels, lymph capillaries, the spleen, tonsils, thymus and various ducts; as
seen in figure 1.1. Unlike the circulatory system the lymphatic system has no ‘pump’ (the
heart) to push the fluid around the system. It instead uses the contractions of smooth and
skeletal muscles to keep the flow of lymphatic fluid around the body. If these contractions
and relaxations are compromised the fluid can build-up and cause complications throughout
the body as the normal functions of the lymphatic system are disrupted. The lymphatic
system contributes in multiple ways in the immunity of the body and the regularity of fluids
throughout the body.
Cervical Lymph Nodes
Palatine Tonsil
Thymus
Axillary Lymph Nodes
Right Lymphatic Duct
Spleen
Thoracic Duct
Cisterna Chyli
Inguinal Lymph Nodes
Popliteal Lymph Nodes
Figure 1.1 The Lymphatic System (Dr Catherine MacInnes, 2015)
, 1.2 Normal Functions of the Lymphatic System
Transportation of lymph
The primary function of the lymphatic system is to direct lymph back into the circulatory
system. What is lymph? Lymph or interstitial fluid is a colourless fluid produced when
plasma from the blood in the circulatory system escapes through gaps in the capillaries due
to high pressure from within the arteries. This plasma, containing no red blood cells, is
called ‘lymph’. The lymph surrounds the tissues outside of the capillaries and if left would
cause swelling as the fluid puts pressure on the outer surface of the tissues. Therefore,
there needs to be a way to remove the lymph and place it back into the bloodstream. This is
where the lymphatic system comes in. The lymph capillaries and vessels have an
overlapping structure so when the lymph puts pressure on the outside of the lymph
capillaries, it allows the fluid in, but the pressure once inside doesn’t allow the lymph to
escape back out. After the lymph has been collected from around the capillaries in the
circulatory system, the lymph vessels connect to the veins nearer to the heart for the
plasma to be circulated around the body again. Without with transportation of lymph the
blood would thicken due to a lack of plasma, reducing the oxygen flow and resulting in
death. The build-up of lymph around the tissues can also cause swelling and discomfort.
Production of Lymphocytes
Lymphocytes are a form of white blood cell that is found in the lymphatic system. There are
two major categories of lymphocytes, B lymphocytes and T lymphocytes that are commonly
referred to as B-cells and T-cells. They both originate from stem cells in the bone marrow.
However, some cells travel to the thymus (an organ within the lymphatic system) to become
T-cells whereas the ones that stay in the bone marrow become B-cells. There is also a
natural killer cell that is a form of lymphocyte. T-cells are responsible for destroying cells
that have been consumed by viruses or have become cancerous, they also regulate the
immune response to foreign bodies. There is a multitude of subcategories of T-cells
including killer T-cells; helper T-cells; regulatory T-cells; memory T-cells; and natural killer T-
cells. B-cells are responsible for creating antibodies to fight foreign bodies known as
antigens. There are also subcategories of B-cells they include memory B-cells and regulatory
B-cells.
Maintaining Interstitial Hydrostatic Pressure
The pressure within the blood vessels is so high that is forces plasma out of pores in the
capillaries. This creates interstitial fluid or ‘lymph’. The lymph is removed and decreases the
pressure inside the blood vessels. It is ideal to maintain the interstitial hydrostatic pressure
to optimise the ability for gas exchange across the cell membrane.
Absorption and Transportation of Fats
Nutrients enters the blood stream via the holes within the capillaries and are then circulated
to the cells throughout our bodies. However, the digested fats that come from the small
intestine are too big to enter through the capillaries and are instead picked up by the lymph
1.1 Introduction to the Lymphatic System
The lymphatic system is a network of organs, nodes and vessels that works in parallel to the
circulatory system, running through the whole body. The system is comprised of lymph
nodes, lymph vessels, lymph capillaries, the spleen, tonsils, thymus and various ducts; as
seen in figure 1.1. Unlike the circulatory system the lymphatic system has no ‘pump’ (the
heart) to push the fluid around the system. It instead uses the contractions of smooth and
skeletal muscles to keep the flow of lymphatic fluid around the body. If these contractions
and relaxations are compromised the fluid can build-up and cause complications throughout
the body as the normal functions of the lymphatic system are disrupted. The lymphatic
system contributes in multiple ways in the immunity of the body and the regularity of fluids
throughout the body.
Cervical Lymph Nodes
Palatine Tonsil
Thymus
Axillary Lymph Nodes
Right Lymphatic Duct
Spleen
Thoracic Duct
Cisterna Chyli
Inguinal Lymph Nodes
Popliteal Lymph Nodes
Figure 1.1 The Lymphatic System (Dr Catherine MacInnes, 2015)
, 1.2 Normal Functions of the Lymphatic System
Transportation of lymph
The primary function of the lymphatic system is to direct lymph back into the circulatory
system. What is lymph? Lymph or interstitial fluid is a colourless fluid produced when
plasma from the blood in the circulatory system escapes through gaps in the capillaries due
to high pressure from within the arteries. This plasma, containing no red blood cells, is
called ‘lymph’. The lymph surrounds the tissues outside of the capillaries and if left would
cause swelling as the fluid puts pressure on the outer surface of the tissues. Therefore,
there needs to be a way to remove the lymph and place it back into the bloodstream. This is
where the lymphatic system comes in. The lymph capillaries and vessels have an
overlapping structure so when the lymph puts pressure on the outside of the lymph
capillaries, it allows the fluid in, but the pressure once inside doesn’t allow the lymph to
escape back out. After the lymph has been collected from around the capillaries in the
circulatory system, the lymph vessels connect to the veins nearer to the heart for the
plasma to be circulated around the body again. Without with transportation of lymph the
blood would thicken due to a lack of plasma, reducing the oxygen flow and resulting in
death. The build-up of lymph around the tissues can also cause swelling and discomfort.
Production of Lymphocytes
Lymphocytes are a form of white blood cell that is found in the lymphatic system. There are
two major categories of lymphocytes, B lymphocytes and T lymphocytes that are commonly
referred to as B-cells and T-cells. They both originate from stem cells in the bone marrow.
However, some cells travel to the thymus (an organ within the lymphatic system) to become
T-cells whereas the ones that stay in the bone marrow become B-cells. There is also a
natural killer cell that is a form of lymphocyte. T-cells are responsible for destroying cells
that have been consumed by viruses or have become cancerous, they also regulate the
immune response to foreign bodies. There is a multitude of subcategories of T-cells
including killer T-cells; helper T-cells; regulatory T-cells; memory T-cells; and natural killer T-
cells. B-cells are responsible for creating antibodies to fight foreign bodies known as
antigens. There are also subcategories of B-cells they include memory B-cells and regulatory
B-cells.
Maintaining Interstitial Hydrostatic Pressure
The pressure within the blood vessels is so high that is forces plasma out of pores in the
capillaries. This creates interstitial fluid or ‘lymph’. The lymph is removed and decreases the
pressure inside the blood vessels. It is ideal to maintain the interstitial hydrostatic pressure
to optimise the ability for gas exchange across the cell membrane.
Absorption and Transportation of Fats
Nutrients enters the blood stream via the holes within the capillaries and are then circulated
to the cells throughout our bodies. However, the digested fats that come from the small
intestine are too big to enter through the capillaries and are instead picked up by the lymph
