6. Lymphatic drainage of the thorax Flashcards
(26 cards)
More fluid leaves blood capillaries than returns to them. What would uncompensated fluid movement from blood to the extracellular fluid result in?
Oedema and loss of blood volume
Why do we have a lymphatic system?
To drain excess extracellular fluid back into the blood via a network of channels truncated by enlargements (Lymph nodes)
To ensure foreign particles come into contact with immune system
How many lymph nodes are there in humans?
600-700
List 4 structures in the lymphatic system
Tonsils
Adenoids
Spleen
Thymus
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.
Rest of body drains via the thoracic duct into the left subclavian vein.
What is the size of a normal lymph node?
2.5 cm
What happens to cell debris and waste products that enter lymphatic vessels?
Lymph is “filtered” (brought into contact with immune system) in lymph nodes
Describe the movement of lymph
Slow and sporadic (no “pump”)
Unidirectional due to presence of valves
What do lymph nodes contain?
Lymphocytes
Macrophages
How is drainage from infected regions detected?
Enlarged lymph nodes
What is a common cause of enlarged lymph nodes?
Infection
e.g. in neck of children in some respiratory infections
List 3 uncommon causes of enlarged lymph nodes
Cancer
TB
Arthritis
Describe lymph in most vessels
Colourless and odourless
Describe lymph in vessels from small intestine
Opaque and milky due to the fats absorbed
Called “chyle”
What causes movement of lymph through the vessels?
Skeletal muscle contraction
Pulses in arteries
What 3 groups of lymph nodes does the thoracic wall drain to?
Parasternal (associated with internal thoracic arteries)(anterior)
Intercostal (posterior)
Diaphragmatic
Which larger lymph vessels do these 3 groups of nodes that drain the chest wall drain to?
Parasternal: into bronchomediastinal trunk
Upper intercostal: into bronchomediastinal trunk
Lower intercostal: into thoracic duct
Diaphragmatic: into brachiocephalic nodes and aortic/lumbar part of the thoracic duct
Superficial: axillary and parasternal nodes
Where does the thoracic duct start? State the vertebral level.
It begins at the cisterna chyli
L2
Describe the path of ascension of the thoracic duct.
Ascends on the right of midline, in between the aorta and azygos vein.
It crosses over to the left side at T5
It empties into the junction between left internal jugular and left subclavian vein
Where do the lymphatics in the lungs drain to?
Tracheobronchial nodes
Where do the lymphatic vessels of the lung drain from?
From within the lung through the hilum
What do the tracheobronchial lymph vessels join with and what does this form?
Join the parasternal and brachiocephalic lymph vessels to form the BRONCHOMEDIASTINAL trunk
What can change the sub-carinal angle?
Enlargement of the large collection of lymph nodes below the sub-carinal angle
Describe the lymphatic drainage of the heart.
Follows the coronary arteries and drains into the:
Tracheobronchial nodes
Brachiocephalic nodes
