Thoracic duct Flashcards
Describe the thoracic duct
The thoracic duct is the largest lymphatic vessel in the
body. It extends from the upper part of the abdomen
to the lower part of the neck, crossing the posterior and
superior parts of the mediastinum. It is about 45 cm/
18 inch long.
Course of the thoracic duct
The thoracic duct begins as a continuation of the upper
end of the cisterna chyli near the lower border of the
twelfth thoracic vertebra and enters the thorax through
the aortic opening of the diaphragm (see Fig. 12.16).
It then ascends through the posterior mediastinum
from level of twelfth thoracic vertebra to fifth thoracic
vertebra, where it crosses from the right side to the left
side. Then it courses through the superior mediastinum
along the left edge of the oesophagus and reaches the neck.
In the neck, it arches laterally at the level of the
transverse process of seventh cervical vertebra. Finally
it descends in front of the first part of the left subclavianartery and ends by opening into the angle of junction
between the left subclavian and left internal jugular
veins .
Why does the thoracic duct have a beaded appearance
It has a beaded appearance because of the
presence of many valves in its lumen.
Commencement of the thoracic duct
It commences in the cysterna chyli, on a level with 12th thoracic vertebrae between aorta and azygos vein
Tributaries of thoracic duct
Main tributaries: left and right lumbar lymph trunks
Left and right intestinal lymph trunks Their confluence is called cysterna chyli.
Additional tributaries: mediastinal lymph trunks
left jugular trunk
left bronchomediastinal trunk, left subclavian trunk
