Thoracic Duct

Thoracic Duct

A major element of the lymphatic system is the thoracic duct. Let us know more on some facts about the thoracic duct and its functions in the lymphatic system, in the article below.
Bodytomy Staff
The human body has a complicated network, that makes an effective functioning system. No doubt, circulation of the blood is one of the vast and major functions in the body. Now, the lymphatic system has the job of returning the fluid from other tissues of the body to the blood stream. Well, this fluid is the excess fluid that leaks from the tiny blood capillaries, and to prevent storage of this fluid that can cause swelling and more complications, the lymphatic system comes to the rescue. The lymphatic system is also responsible for absorbing the fats (lipids) from the intestine. It has many components that help it function effectively and smoothly. One of its major components is the thoracic duct, it is a type of a lymphatic duct, and also the largest lymphatic vessel. It is a thin tube like structure, around 2 - 3 mm in diameter. It emerges at the lower end of the spinal cord, through the chest and then ends towards the back left side of the neck. This opens up into a blood vessel. This blood vessel is actually the junction where the left subclavian vein and the internal left jugular vein join. This duct is also known with other names like the alimentary duct or the chyliferous duct.

All the lymphatic vessels from the lower pelvis and chest, lower limbs, and abdomen, empty in the thoracic duct, except for those which are situated in the upper right quadrant of the body. The fluid that travels through this duct is called lymph, which consists of white blood cells and is similar to blood plasma. Other components of this fluid are: salt, glucose, urea, protein and water. This lymph travels through the thoracic duct and empties in the vein junction, from here the fluid is deposited back into the blood. To prevent the blood from getting back into the thoracic duct, there is a valve that functions as a blockage and barrier. This valve is actually located at the point of junction where the thoracic duct and venous system meet. This is the anatomy of the thoracic duct. Below are some more facts on the functions, take a look.


As we know the major role of the thoracic duct is to collect the fluid from various parts of the body and deposit it back in the blood stream. This system can also be described as a low pressure activity, that resembles a drainage method. It only does not get rid of the fluid, but transports this fluid back into the blood stream. The duct is a sac like inflated structure, which precisely collects all the fluid (lymph) from areas like, the abdomen, lower limbs and lower chest, etc. The thoracic duct needs some pumping that will help the fluid travel along the duct and empty it in the blood stream. This is provided by the activity like breathing, of the internal muscles of the duct which are smooth, and by the valves in the duct. This creates the flow of fluid, and prevents it from traveling down again. This is very different from other organs, that require the pump mechanism from the heart. This function mainly helps the body in cleansing of the cells. This is an important part of the lymphatic system, which is essential for the proper functioning of the body.

This system of draining the fluid and back in the blood stream can create complications if blocked or if it does not function properly. Damage usually does not occur internally by its own. Most of the time external trauma or side effects of surgical procedures will be the cause. The fluid will build up in the duct and also in many other parts of the body. A condition called chylothorax can result as an effect of the accumulation of lymph in a certain region. Treatment is necessary in such a condition, which will mainly rely on removing the blockage.

The thoracic duct definitely means a lot to the effective functioning of the body. Taking care and some appropriate measures that prevent damage to this duct, are the best ways to keep it working efficiently.
Human anatomy scientific illustrations: Thoracic duct
Thoracic duct