3. Thoracic duct
- Is the largest lymphatic trunk which drains
chyle(product of fat digestion) & most lymph of
body.
- Extent- Upper abdomen at lower border of T12
to lower part of neck, crossing post & sup
mediastinum
- 45cms long & 0.5cms wide
- Appears Beaded due to presence of many valves
in its lumen 3
4. Drains lymph from whole of body except
• Rt side of head & neck
• Rt upper limb
• Rt lung & thoracic wall
• Rt side of heart and rt surface of liver
Area of drainage
4
7. Course:
Begins in abdomen at lower border of T12 as a continuation
of cisterna chyli
Enters post mediastinum through aortic opening of
diaphragm(T12)
At T5 shifts to left & runs in superior mediastinum
At C7 (root of neck) arches laterally, then downwards
Ends at angle formed by union of left int jugular vein
& lt subclavian vein, (regurge of blood prevented by
a pair of valves)
7
14. Tributaries:
Receives lymph from both halves below diaphragm
through Cisternae chyli & Lt half above diaphragm
1. From post IC lymph nodes of lower 6 spaces
2. From upper lumbar nodes(paraaortic LN)
3. From Post Mediastinal lymph nodes & post IC LNs of
upper 6 IC spaces
4. From axilla through Lt Subclavian trunk
5. From nodes in Lt ½ of H & N thru Lt Jugular trunk
6. From Lt half of thorax (Lt lung & Lt side of heart) through
Lt Bronchomediastinal trunk
14
15. Applied anatomy
Obstruction of Thoracic duct – Due to mature
filarial parasites lymph vessels get burst
chylothorax, chyloperitoneum, chyluria.
Cervical part of thoracic duct is damaged in
block dissection of neck
Thoracic duct is very thin walled and colourless
so more prone for injury during surgery in post
mediastinum. 15