Job of the Lymphatic System:
What the lymphatic system is:
Source: Patient information website of Cancer Research UK
‘The lymphatic system is a system of thin tubes that runs throughout the body. These tubes are called lymph vessels or lymphatic vessels.
The lymphatic system is like the blood circulation – the tubes (vessels) branch through all parts of the body like the arteries and veins that carry blood. But the lymphatic system tubes are much finer and carry a colorless liquid called lymph.
Lymph is a clear fluid that circulates around the body tissues. It contains a high number of lymphocytes (white blood cells). Plasma leaks out of the capillaries to surround and bathe the body tissues. This then drains into the lymph vessels. The fluid, now called lymph, then flows through the lymphatic system to the biggest lymph vessel – the thoracic duct. The thoracic duct then empties back into the blood circulation.
Along the lymph vessels are small bean-shaped lymph glands or ‘nodes’. You can probably feel some of your lymph nodes. There are lymph nodes in many parts of your body including:
There are also lymph nodes that you cannot feel in
Other lymphatic system organs
The lymphatic system includes other body organs. These are the:
The spleen is under your ribs on the left side of your body. The spleen has two main different types of tissue, red pulp and white pulp. The red pulp filters worn out and damaged red blood cells from the blood and recycles them. The white pulp contains many B lymphocytes and T lymphocytes. These are white blood cells that are very important for fighting infection. As blood passes through the spleen, these blood cells pick up on any sign of infection and begin to fight it.
The thymus is a small gland under your breast bone. The thymus helps to produce white blood cells. It is usually most active in teenagers and shrinks in adulthood.
The tonsils are two glands in the back of your throat. The adenoids are at the back of your nose, where it meets the back of your throat. The tonsils and adenoids (also called the ‘nasopharyngeal’ tonsils) help to protect the entrance to the digestive system and the lungs from bacteria and viruses.
What the lymphatic system does
The lymphatic system does several jobs in the body. It
Draining fluid into the bloodstream
As the blood circulates, fluid leaks out from the blood vessels into the body tissues. This fluid is important because it carries food to the cells and waste products back to the bloodstream. The leaked fluid drains into the lymph vessels. It is carried through the lymph vessels to the base of the neck where it is emptied back into the bloodstream. This circulation of fluid through the body goes on all the time.
The lymph nodes filter the lymph fluid as it passes through. White blood cells attack any bacteria or viruses they find in the lymph as it flows through the lymph nodes. If cancer cells break away from a tumor, they often become stuck in the nearest lymph nodes. This is why doctors check the lymph nodes first when they are working out how far a cancer has grown or spread.
Filtering the blood
This is the job of the spleen. It filters the blood to take out all the old worn out red blood cells and then destroys them. They are replaced by new red blood cells that are made in the bone marrow. The spleen also filters out bacteria, viruses and other foreign particles found in the blood. White blood cells in the spleen attack bacteria and viruses as they pass through.
When people say, “I’m not well, my glands are up” they are really saying they have swollen lymph nodes because they have an infection. Many ways the lymphatic system helps fight infection include:
This function of the lymphatic system is really part of the Immune System.’
Thoracic Duct and the Thymus Gland
There are two body parts that we have referenced previously that require specific focus for this training because of the vital role they play in immunity. And, most important to our job as yoga teachers, we can use yoga to support and strengthen their function in providing immune protection. We highlighted them here using these definitions and references.
Source: Healthline.com http://www.healthline.com/human-body-maps/thoracic-duct#6/1
“The thoracic duct is the biggest lymphatic vessel in the human body, and plays a key role in the lymphatic system. It is also called the left lymphatic duct or the alimentary duct. A large part of the body’s lymph is collected by this duct, and drained into the bloodstream near the brachiocephalic vein between the internal jugular veins and the left subclavian. The typical length of this duct in an adult averages between 38 and 45cm and the diameter is about 5mm. It originates from the second lumbar vertebra level and goes to the neck’s root. The duct arises from the combination of the left and right lumbar trunks and the intestinal trunk in the abdomen. The thoracic duct gets extended in the chest area and from there it curves towards the internal jugular vein and the left carotid artery at the C7 vertebra. It travels through the aortic aperture diaphragm and rises along the posterior mediastinum. It carries up to four liters of lymph each day. This action is primarily caused by the breathing action and assisted by the smooth muscle of the duct.”
In adults, the thoracic duct transports up to 4 L of lymph per day. The lymph transport in the thoracic duct is mainly caused by the action of breathing, aided by the duct’s smooth muscle and by internal valves that prevent the lymph from flowing back down again. For more images and information about the thoracic duct, the largest lymphatic vessel, go to www.healthline.com/human-body-maps/thoracic-duct.
What is the Thymus Gland?
Source: Inner Body.com http://www.innerbody.com/image_endoov/lymp04-new.html
“The thymus gland is a gland that forms part of the Immune System. It is situated in the upper part of the chest, behind the breastbone, and is made up of two lobes that join in front of the trachea. Each lobe is made of lymphoid tissue, consisting of tightly packed white blood cells and fat. The thymus enlarges from about the 12th week of gestation until puberty, when it begins to shrink. Its function is to transform lymphocytes (white blood cells developed in the bone marrow) into T-cells (cells developed in the thymus). These cells are then transported to various lymph glands, where they play an important part in fighting infections and disease. Swelling of lymph glands and fever are a signal that immune cells are multiplying to fight off invaders of the body: bacteria, fungi, viruses or parasites.
T cells are your fighter cells. They help the Immune System kill invaders to the body, such as bacteria. T cells, frontline defenders of the Immune System, recognize cells that don’t belong in the body—such as bacteria—and set off a cascade of events to kill them.
Exercise is proven to increase the ‘responsiveness’ of T cells in cancer survivors so they are able to better defends against secondary cancers and others types of infections.”
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