Lymphatics of Thoracic Wall

Question 1

The superficial tissues of the thoracic wall drainage

Answer 1

• The superficial tissues of the thoracic wall are drained to the axillary lymph nodes (in the armpit/axillary region).

Question 2

The deep tissues of the thoracic wall are drained to three groups of lymph nodes:

Answer 2

o Posterior intercostal lymph nodes (posterior end of intercostal space)

o Phrenic lymph nodes (superior surface of thoracic diaphragm - anterior and posterior)

o Parasternal lymph nodes (accompanying internal thoracic arteries)

Question 3

Parasternal Lymph Nodes

Answer 3

• Also called internal mammary or internal thoracic lymph nodes.
• 4 to 5 LNs on each side of sternum, located adjacent to internal thoracic blood vessels.
• Receives afferent vessels from anterior thoracic wall, anterior phrenic LNs and medial half of breast.
• Efferent vessels travel to bronchomediastinal trunk.

Question 4

Posterior Intercostal Lymph Nodes

Answer 4

• Small lymph nodes located in paravertebral region of intercostal spaces.
• Receives afferent vessels from posterolateral thoracic wall.
• Efferent vessels from superior 4-5 intercostal spaces travel to posterior mediastinal LNs.
• Efferent vessels from inferior 6-7 intercostal spaces travel to inferior intercostal trunks.

Question 5

Phrenic Lymph Nodes

Answer 5

• Located on the superior surface of thoracic diaphragm, arranged into anterior and posterior groups.
• Receives afferent vessels from thoracic diaphragm and liver.
• Efferent vessels from anterior phrenic LNs travel to parasternal LNs posterior to xiphoid process.
• Efferent vessels from posterior phrenic LNs travel to posterior mediastinal LNs superior to crura of thoracic diaphragm.

Question 6

Brachiocephalic Lymph Nodes

Answer 6

• Located in the superior mediastinum anterior to the confluence of the brachiocephalic veins, superior vena cava and aortic arch.
• Receives afferent vessels from the thymus and pericardium.
• Efferent vessels travel to the pretracheal LNs.

Question 7

Posterior Mediastinal Lymph Nodes

Answer 7

• Located anterolateral to the vertebral column.
• Receives afferent vessels from the posterior phrenic LNs, superior 4-5 posterior intercostal LNs, oesophagus and pericardium.
• Efferent vessels travel to the thoracic duct, bronchomediastinal trunks or bronchotracheal LNs.

Question 8

Course of the Thoracic Duct

Answer 8

The thoracic duct courses posterior to the oesophagus and is located to the right of the thoracic aorta and to the left of the azygos vein.

Question 9

Superficial Lymphatic Plexus

Answer 9

• The superficial lymphatic plexus is located deep to the visceral pleura and drains the visceral pleura and lung tissue

Question 10

Deep Lymphatic Plexus

Answer 10

• The deep lymphatic plexus surrounds the intrapulmonary blood vessels and bronchi and drains the structures forming the root of the lung.

Question 11

Pulmonary Lymph Nodes

Answer 11

• Located within the lung along the secondary bronchi in each lobe.
• Efferent vessels will drain into the bronchopulmonary/hilar lymph nodes.

Question 12

Bronchopulmonary Lymph Nodes

Answer 12

• Located at the hilum of the lung.

* Afferent vessels from pulmonary lymph nodes, efferent vessels to bronchotracheal lymph nodes

Question 13

Inferior Bronchotracheal Lymph Nodes

Answer 13

• Located along the carina of the trachea.

* Afferent vessels from bronchopulmonary/hilar lymph nodes, efferent vessels to superior bronchotracheal lymph nodes.

Question 14

Superior Bronchotracheal Lymph Nodes

Answer 14

• Located at the right and left angle between the trachea and primary bronchi.
• Afferent vessels from inferior bronchotracheal lymph nodes, efferent vessels to right or left bronchomediastinal trunk directly or via paratracheal lymph nodes.

Question 15

Mammary Glands of Breast

Answer 15

• Alveoli of lobules

* Lactiferous ducts and lactiferous sinuses open into nipple in centre of areola

Question 16

Variations of the Breast

Answer 16

• Accessory Breasts (polymastia) and nipples (polythelia)

* May develop along embryonic mammary ridge (milk line)

Question 17

Axilla

Answer 17

• The axilla is a pyramidal-shaped region and forms the gateway to the brachium (arm).
• It contains a number of lymph nodes, blood vessels and nerves.
• The walls are made up of numerous muscles.
• The structure of the axillary region consists of an apex, base/floor, anterior wall, posterior wall, medial wall and lateral wall.

Question 18

Major Contents of the Axilla

Answer 18

• axillary artery
• axillary vein
• parts of brachial plexus
• axillary lymph nodes (5 groups)
• fat

Question 19

Axillary Lymph Nodes

Answer 19

• Pectoral/anterior axillary
• Humeral/lateral axillary
• Subscapular/posterior axillary
• Central axillary
• Subclavian/apical axillary

Question 20

Lymphatics of Female Breast

Answer 20

• The subareolar lymphatic plexus surrounds the areola and receives lymph from the areola, nipple and lobules of the mammary gland.
• Approximately 75% of the efferent vessels from the lateral 2/3rds of the breast travel to the axillary lymph nodes (mostly the pectoral/anterior LNs).
• Approximately 25% of the efferent vessels from the medial breast travel to the parasternal lymph nodes.
• Lymph from the inferior breast may pass to the anterior phrenic LNs.

Question 21

Infraclavicular & Supraclavicular lymph nodes

Answer 21

• Lymph from the axillary lymph nodes travel into the infraclavicular and supraclavicular LNs before draining into the subclavian trunk.