Damage Caused By High Blood Pressure
31st August 2017
The Human Heart
31st August 2017

Lymphatic & Blood Systems


The Lymphatic System is the most complex, yet interesting subject I’ve researched to date. It would take me a lifetime to completely understand the lymphatic system, the information below is just an overview. I took the decision to include information on the lymphatic system, having read how a poor or badly functioning lymphatic system can cause some serious medical conditions, which in turn can be a cause of elevated blood pressure. Some of these conditions are listed in this section.

The Lymphatic System is an integral part of the human body’s circulatory system and plays a critical part in the immune system, regulating blood pressure and supporting many bodily functions. Your lymphatic system is responsible for moving lymph, which is a watery clear liquid, through its own one-way valves through vessels.
However, the Lymphatic System has no circulatory system of its own, instead waste is removed from the body by muscle and body movement. As you breathe, your muscles move lymph fluid around your body towards the heart.

Lifestyle can have an adverse effect on removing lymph from your body especially if you eat late or just before going to sleep. Further information on how the lymphatic system works while you are sleeping, is explained in section 25 in the Members Section on Sleep.
Further information on the Glymphatic System, Sympathetic Nervous System, Obesity, and particularly the “Inguinal Nodes”, and how these conditions can impact the lymphatic system, will be included in a new section on Obesity in the Members Section.

The Lymphatic System works to protect the body from infections and diseases caused by toxins and bacteria that pass into the lymph fluid. This fluid passes through lymph nodes, where white blood cells attack intruders to destroy them.

What are White Blood Cells?

White Blood Cells consist of a number of cells including leukocytes. They are the immune cells that protect our bodies from bacteria, viruses, infection and more.
Where do they come from? Cells originate in bone marrow which is found in the centre of our bones. They start off as stem cells, which split to form Lymphoid Stem Cells. These cells then develop into lymphocytes, which are one of many types of White Blood Cells. There are B cells and T cells (for those interested, there are websites that explain more).
The white blood cells travel around the lymphatic system fighting the bacteria and viruses. Its these viruses and bacteria that make you feel unwell.

As the lymphatic system has no pump to move lymph, it relies on muscles contracting and relaxing, and body movement, to move lymph to veins at the base of the neck, where lymph containing waste is returned into the bloodstream. Once the lymphatic waste is in the circulatory system, the heart pumps the waste to the kidneys where it is excreted with urine, and via the bowels. In addition, waste is also exhaled from the lungs and sweat glands.
High Blood Pressure, when related to the lymphatic system, is an increase in blood pressure that may be caused when the lymphatic system fails to move lymph waste. This can have an effect on the veins and arteries in the blood circulatory system from the heart.
Essential hypertension, known as primary hypertension, doesn’t have a known secondary cause. More about primary and secondary hypertension in the Home Section, titled “Types of Hypertension”.
Remember Ideal Blood Pressure has been said by the medical profession to be between 120/80mmHg and 90/60mmHg.

A sluggish lymphatic system can also have an impact on blood pressure. A blockage in the lymphatic system can sometimes cause swollen tissue. This may cause a condition called lymphodema, symptoms may include:
  • Headaches
  • Weight gain
  • Swollen fingers
  • Swelling in arms & legs
  • Digestion problems
  • Feeling fatigued
  • Dry itchy skin
  • Swollen lymph nodes
  • Feeling depressed
  • Feeling stiff on waking
  • Water retention
Should you feel any of the symptoms above are of concern to you, you should discuss them with a doctor or health professional, who may be able to provide advice and treatment. Several of the symptoms detailed above may also cause high blood pressure, which is referred to as secondary (not primary) hypertension. Secondary hypertension is explained further in section 2 of this website.
However, always remember that the conditions listed above do not necessarily mean your lymphatic system isn’t working as it should, there may be other conditions that need investigating.

Lymphatic massage

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There are six components that make up the lymphatic system as detailed below:

The Thoracic Duct, also referred to as the left lymphatic duct, is the body's largest lymphatic vessel, which can be compared to veins. It carries more than 70% of waste from lymph nodes. This waste is emptied into the subclavian veins, which take this waste, together with blood to the heart. The heart pumps the lymph and fresh blood into the bloodstream, and waste is excreted from the body via the kidneys, bowels, lungs and skin.
The right lymphatic duct drains fluid from other parts of the upper body, including the right arm, right side of the neck and head etc.

Lymph Nodes are part of the lymphatic system, and also part of the immune system, their function is to filter dangerous substances, bacteria, viruses etc. They also fight infection, destroying germs, and filtering out waste and dead cells which are carried in the lymph fluid through the lymphatic vessels to the thoracic duct and to the heart.

Lymphatic vessels , which carry lymph fluid through the lymphatic system, can be likened to veins, but only because they both carry fluids. Veins are part of the circulatory system, and carry blood to the heart, and have one-way valves to stop backflow. Lymphatic vessels take lymph to the heart. However, as the lymphatic system is not a circulatory system, these vessels are sealed at one end and have one-way valves to stop the backflow of lymph fluid.

The Thymus gland is the main organ of the lymphatic system, located between the breast bone and the heart. Although the thymus is responsible for other functions connected with the endocrine system, it’s mainly connected with the immune system. This gland assists the development of cells specific to the immune system called T Lymphocytes, these T Cells are part of the body’s immune system. Apart from other functions, T Cells can kill cells that may turn into cancer cells.

The spleen is the largest lymphatic organ in the body, located just above the kidneys. The spleen is responsible for the amount of red blood cells in the body, removing damaged old blood cells together with any foreign matter that may cause infection with white blood cells, together with macrophages which are a type of large specialised white blood cells, they act like an army digesting any foreign substances, cellular debris, cancer cells and any matter not conducive to a healthy body.

6. Tonsils

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Tonsils, together with adenoids, are a part of the lymphatic system (the immune system). They work by trapping germs inhaled through the nose and mouth. Unlike other lymph nodes which are beneath the skin, tonsils are visible in the throat. This begs the question, what are the implications when tonsils and adenoids are removed? From the research I’ve carried out, opinions differ slightly. Some research indicates the tonsils are no longer needed when people become adults. From the information I’ve read, the consensus of opinions is that when tonsils and adenoids are removed, there doesn’t seem to be a negative effect on the immune system.

Lymphatic Vessels

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Lymphatic vessels dispose of the fluids (Lymph) into your venous blood stream. As you may have read, you have miles of veins and arteries; however you only have around 650 lymph nodes in your body. Unlike your blood system which relies on the heart to circulate, the lymphatic system doesn’t have a pump; as explained above, lymph is moved around the body by daily activity, so when you sit down or are confined to bed, your lymph waste doesn’t get drained so easily from the body.

Lymph Nodes that have become swollen can be an indication of disease, and together with other symptoms can assist a doctor in diagnosing underlying conditions. There are on average around 650 lymph nodes in the human body, around 300 lymph nodes are located around the area of the abdomen, while the groin and armpits account for some 110. There are a large number of lymph nodes around the neck, the remainder are in various other areas of the body.

Swollen lymph nodes can be caused by several conditions, some minor, some serious, so it's always best to get them checked. Lymph nodes when enlarged or swollen indicate infection caused by bacteria, a virus or other microorganisms. These intruders are then attacked by white blood cells, causing the lymph node to enlarge or swell.

One interesting fact, people often refer to swollen lymph nodes as swollen lymph glands, this is incorrect. Lymph nodes are not glands as they do not secrete or produce any substances. They contain immune cells (White Blood Cells) and act as filters of the lymph fluid, which may carry infection, bacteria, viruses etc.

In Summary

There are in principal two circulatory systems in the human body.
  • Human blood is continuously being circulated by the heart around the miles of arteries and veins in the body, taking around 60 seconds to complete each round trip.
  • The other is the Lymphatic system. Although it’s sometimes referred to as a circulatory system, vessels in the lymphatic system do not circulate; in fact, it's made up of lymphatic vessels, each of which is sealed at one end and has non-return valves to stop the backflow of lymph. This system moves fluid from the tissues and directs it via the lymph nodes back to the circulatory system.
The body’s circulatory system takes red blood cells, white blood cells, platelets and plasma from the heart, through the network of arteries, capillaries, veins, portal veins, then through the lungs to exhale waste and bring fresh oxygenated blood to the heart to start the journey over again.
It’s this circulatory system that transports blood to the organs in your body, carrying nutrients, electrolytes, hormones, oxygen and in turn carbon dioxide, to help keep your body nourished and helps to maintain your immune system that fights infection and disease. The circulatory system is also covered in section one. “Facts” and other sections within this website.

Your Heart

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Your arteries

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Your veins

Your veins are blood vessels carrying blood back to the heart; unlike arterial blood which is coloured red, blood returning to the heart is tinged blue.
There are two routes into the heart chambers; the vein returning blood from the upper part of your body, (the chest, upper limbs and the head) is called the Superior Vena Cava, the vein returning blood from the lower body, (the stomach, liver, kidneys and lower limbs) is called the Inferior Vena Cava. You can see where the veins come into the heart on the illustration earlier in this section.

Your lungs

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Your lungs receive deoxygenated blood directly from your heart via two pulmonary arteries. The right pulmonary artery brings deoxygenated blood to the right lung, the left pulmonary artery brings deoxygenated blood to the left lung. The pulmonary arteries are the only arteries that carry deoxygenated blood.
The lungs exchange carbon dioxide and other waste with fresh oxygenated blood that will be returned to the heart through the left and right pulmonary veins, the only veins that carry oxygenated blood. The heart then pumps fresh oxygenated blood through the circulatory system to organs that keep you alive. More on the circulatory system in section 5 of this website.
The next question is “How does the oxygen we breathe get into our blood stream?” We have two lungs; the left lung is slightly smaller to allow space for the heart. Two thin layers cover each lung, these are called the pleura; one layer is attached to the chest wall, the other encases the lung. The inside of the lung looks like a sponge.
When we breathe, air travels down our windpipe through the bronchial tubes which keep dividing up to thirty-four times, ending at the bronchiole which connects to the alveoli. There are around 300 million alveoli in our lungs, it is here that the transfer of oxygen and carbon dioxide are exchanged.
What is amazing is that the thickness of the wall between the alveoli and the blood stream is only around one micron thick, that’s really thin, one micron is one millionth of one metre. To give a more visual comparison, a human hair on average is between 20 and 170 microns thick!
Capillaries wrap themselves around each alveolus,
Alveolus - are tiny air sacs of the lungs which allow for rapid exchange of gases which includes oxygen and carbon monoxide.
the capillary bringing oxygen deficient blood from the heart and exchanging it with oxygen-rich red blood, the oxygen being transported by a protein within the red blood cells called haemoglobin, in order to carry it to the rest of your body.
Smoking has a negative impact on the circulatory system. There are around 300 million alveoli sacs within the lungs that are critical in the transfer of deoxygenated blood, carbon dioxide, waste from the body, and waste from the lymphatic system, then taking fresh oxygenated blood back to the heart and circulatory system.
When people inhale tobacco smoke they also inhale more than 4000 chemicals; these chemicals, cyanide, arsenic and more, travel down the bronchial tubes until they reach the alveoli, which become blocked with the thick tar like substance inside the lungs. This restricts the exchange of deoxygenated blood and waste with fresh oxygenated blood that keeps everyone alive. It’s the restriction in the lungs that eventually makes it difficult to breathe, which in turn can cause other life-threatening conditions. You can find a lot more on smoking in sections 10 and 16.

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