The thoracic duct is the main lymphatic vessel that transports lymph from throughout the body. It begins at the cisterna chyli where it collects lymph from the lower body and abdomen. It ascends through the thorax, traveling along the vertebral column and passing through the diaphragm. In the neck, it arches forward and drains into the left subclavian vein. The thoracic duct transports around 4 liters of lymph per day to return excess tissue fluid to the bloodstream.

1. Thoracic Duct
Dr Rajiv Ranjan

2. Lymphatic system
Lymph
Lymphocytes
Lymphatic plexuses
Lymphatic vessels
Lymph nodes
Lymphoid organs
Superficial lymphatic vessels
Deep lymphatic vessels
Lymphatic trunk

3. Lymphatic system is absent in CNS ?, cornea, cartilage, Thymus
superficial layer of skin, bones & alveoli of lungs
Begin as blind ended tube

4. Lymph formation
Lymph is 1/10th of residual fluid

5. Lymphocytes

6. Distribution

7. Lymphatics/Lymphatic Vessels
• Superficial lymphatic vessels
• Deep lymphatic vessels
• Lymphatic trunk

8. Lymph Node

9. Lymphoid Organs

10. Lymphoid Organs

11. Lymphoid Organs

12. MALT

14. Role
Drainage of excess fluid
Cleaning
Defence
Absorption of lipid & vitamins

15. applied
• Lymphadenitis
• Lymphangitis
• Lymphedema
• Lymphogenous spread of cancer

16. Thoracic duct
• AKA left lymphatic duct or the alimentary duct
• Transports up to 4 liters of lymphatic fluid each day (100ml/hr)
• Commences @ upper border of cisterna chyli(T12)
• Traverses through aortic hiatus & ascends betn descending thoracic aorta &
azygos vein
• Vertebral column, the right intercostal arteries and terminal segments of the
hemiazygos and accessory hemiazygos veins lie posteriorly
• Diaphragm and Oesophagus are anteriorly.
• @ T5 it inclines to the left
• @ the root of neck it arches forwards & to the left behind the carotid sheath
• Crossing over the Lt. pleura & Lt subclavian A it enters @ the confluence of Lt.
internal jugular & Lt. subclavian V
• Termination is guarded by a bicuspid valve

19. Cisterna chyli
Confluence of lymphatics
Lie @ L1-2, posterolateral to aorta
Continue into thoracic duct superiorly
Applied – Chylothorax (chylomicrons +ve)

21. Tributaries

22. Tributaries of thoracic duct
 Bilateral descending thoracic lymph trunks from lower
6 intercostal spaces
 Posterior intercostal lymph trunk of upper six left
intercostal spaces
 Bilateral ascending lumbar lymph trunks
 Intestinal trunk
 Left bronchomediastinal trunk
 Left subclavian trunk
 Left jugular trunk

23. Right lymphatic duct

24. Right lymphatic duct
 Receives
Posterior intercostal lymph trunk of upper six right intercostal spaces
Right bronchomediastinal trunk
Right subclavian trunk
Right jugular trunk
• Drains into either right subclavian vein or right internal jugular vein
and rarely right venous angle