1.6 - Lymphatic Drainage of the Thorax Flashcards
How many lymph nodes are there in humans?
600-700
Describe the arrangement of the lymphatics across the body. State where the lymphatics join the venous circulation.
Right upper quadrant drains into the right subclavian vein.
Other three quadrants all drain via the thoracic duct into the left subclavian vein.
What is the size of a normal lymph node?
<2.5cm
What is a common cause of lymphadenopathy?
Infection
What is lymph usually like?
Colourless and odourless
How is lymph from the small intestines different? What is it called?
It is opaque and milky due to absorption of fats (chylomicrons)
It is called chyle
What causes movement of lymph through the vessels?
Skeletal muscles.
Pulses in arteries
What prevents backflow in the vessels?
Valves
What three groups of lymph nodes does the thoracic wall drain to?
Parasternal (associated with internal thoracic arteries)
Intercostal
Diaphragmatic
Which larger lymph vessels do these three groups of nodes drain to?
Parasternal - bronchomediastinal trunk
Upper intercostal - bronchomediastinal trunk
Lower intercostal - thoracic duct
Diaphragmatic - brachiocephalic nodes + aortic/lumbar part of the thoracic duct
Superficial - axillary and parasternal nodes
Where does the thoracic duct start and at what vertebral level?
Cisterna chyli - L2
Describe the path of ascension of the thoracic duct?
The thoracic duct ascends just to the right of midline, in between the aorta and the azygos vein. It crosses over to the left side at T5 and it then empties into the left subclavian vein.
Where do the lymphatics in the lungs drain to?
Tracheobronchial nodes - this is the largest collection of lymph nodes in the body
What do the tracheobronchial lymph vessels join with and what does this form?
Tracheobronchial lymph vessels join the parasternal and brachiocephalic lymph vessels to form the BRONCHOMEDIASTINAL trunk
Describe the lymphatic drainage of the heart.
Lymphatic drainage of the heart follows the coronary arteries and drains into the:
Tracheobronchial nodes
Brachiocephalic nodes