6. Lymphatic drainage of the thorax

Question 1

More fluid leaves blood capillaries than returns to them. What would uncompensated fluid movement from blood to the extracellular fluid result in?

Answer 1

Oedema and loss of blood volume

Question 2

Why do we have a lymphatic system?

Answer 2

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

Question 3

How many lymph nodes are there in humans?

Answer 3

600-700

Question 4

List 4 structures in the lymphatic system

Answer 4

Tonsils
Adenoids
Spleen
Thymus

Question 5

Describe the arrangement of the lymphatics across the body. State where the lymphatics join the venous circulation.

Answer 5

Right upper quadrant drains into the right subclavian vein.

Rest of body drains via the thoracic duct into the left subclavian vein.

Question 6

What is the size of a normal lymph node?

Answer 6

2.5 cm

Question 7

What happens to cell debris and waste products that enter lymphatic vessels?

Answer 7

Lymph is “filtered” (brought into contact with immune system) in lymph nodes

Question 8

Describe the movement of lymph

Answer 8

Slow and sporadic (no “pump”)

Unidirectional due to presence of valves

Question 9

What do lymph nodes contain?

Answer 9

Lymphocytes

Macrophages

Question 10

How is drainage from infected regions detected?

Answer 10

Enlarged lymph nodes

Question 11

What is a common cause of enlarged lymph nodes?

Answer 11

Infection

e.g. in neck of children in some respiratory infections

Question 12

List 3 uncommon causes of enlarged lymph nodes

Answer 12

Cancer
TB
Arthritis

Question 13

Describe lymph in most vessels

Answer 13

Colourless and odourless

Question 14

Describe lymph in vessels from small intestine

Answer 14

Opaque and milky due to the fats absorbed

Called “chyle”

Question 15

What causes movement of lymph through the vessels?

Answer 15

Skeletal muscle contraction

Pulses in arteries

Question 16

What 3 groups of lymph nodes does the thoracic wall drain to?

Answer 16

Parasternal (associated with internal thoracic arteries)(anterior)
Intercostal (posterior)
Diaphragmatic

Question 17

Which larger lymph vessels do these 3 groups of nodes that drain the chest wall drain to?

Answer 17

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

Question 18

Where does the thoracic duct start? State the vertebral level.

Answer 18

It begins at the cisterna chyli

L2

Question 19

Describe the path of ascension of the thoracic duct.

Answer 19

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

Question 20

Where do the lymphatics in the lungs drain to?

Answer 20

Tracheobronchial nodes

Question 21

Where do the lymphatic vessels of the lung drain from?

Answer 21

From within the lung through the hilum

Question 22

What do the tracheobronchial lymph vessels join with and what does this form?

Answer 22

Join the parasternal and brachiocephalic lymph vessels to form the BRONCHOMEDIASTINAL trunk

Question 23

What can change the sub-carinal angle?

Answer 23

Enlargement of the large collection of lymph nodes below the sub-carinal angle

Question 24

Describe the lymphatic drainage of the heart.

Answer 24

Follows the coronary arteries and drains into the:
Tracheobronchial nodes
Brachiocephalic nodes

Question 25

What do the nodes on the aorta receive lymph from?

Answer 25

Oesophagus
Diaphragm
Pericardium
Liver

Question 26

Where do nodes on the aorta drain into?

Answer 26

Thoracic duct

Posterior mediastinal nodes