Thoracic Cavity 2

Question 1

Describe the location of the trachea and what levels the carina moves to during respiration

Answer 1

The trachea starts at C6 vertebra and ends at the bifurcation at the carina (T4). During respiration the carina can move to as low as T6 and high as T4

Question 2

At the level of T3, what structures are viable in a transverse plane?

Answer 2

The brachiocephalic trunk, left common carotid, left subclavian, the brachiocephalic veins and trachea, oesophagus, nerves ect.

Question 3

At the level of T4 what are the structures visable in z transverse plane?

Answer 3

Aortic arch, SVC, arch of azygos, trachea, oesophagus and nerves

Question 4

What is posterior to the sternoclavicular joint?

Answer 4

v - Formation of brachiocephalic veins from the internal jugular and subclavian vein.
a - Division of the brachiocephalic trunk into right common carotid and right subclavian a.

Question 5

What is posterior to the 1st right costal cartilage?

Answer 5

Formation of superior vena cava from the right and left brachiocephalic veins

Question 6

What is posterior to the 2nd right costal cartilage

Answer 6

Arch of azygos vein joins SVC

Question 7

What is posterior to the 3rd right costal cartilage?

Answer 7

SVC enters right atrium

Question 8

What is the posterior wall of the posterior mediastinum made up of?

Answer 8

Vertebral bodies, Posterior costal segments, Proximal segments posterior IC vessels, Proximal segments of IC nerves, and the sympathetic chain with ganglia.

Question 9

Describe how the thoracic aorta forms the abdominal aorta

Answer 9

At the sternal angle the thoracic aorta forms, it lies to the left of thoracic vertebrae but move to the midline in lower thorax. It passes through the diagram behind the oesophagus at T12

Question 10

What are the visceral branches of the thoracic aorta?

Answer 10

These supply the organs of mediastinum:
Osophageal arteries,
Bronchial arteries,
Pericardial branches,
Mediastinal branches and superior phrenic artery (classes as parietal as well)

Question 11

What are the parietal branches of the thoracic aorta?

Answer 11

Posterior intercostal arteries, subcostal arteries and (superior phrenic artery)

Question 12

Where does the oesophagus start and peirce the diaphragm?

Answer 12

Starts at C6, descends between vertebral column and trachea then pierces the diaphragm at T10

Question 13

Describe what type of muscle is the oesophagus made up off?

Answer 13

Upper 1/3 - straited and voluntary. Middle 1/3rd is mix of smooth and striated. Lower 1/3rd is smooth

Question 14

Name the 4 constrictions of the oesophagus

Answer 14

Upper oesophageal sphincter, where it is crossed by arch of aorta, where is is compressed by the left main bronchus and at the diaphragm. (left atrium causes narrowing)

Question 15

What is are the clinical significance of the 4 oesophageal constrictions?

Answer 15

They are more likely to cause a blockage, hinder the passage of instruments and slow down the passage of caustic substances leading to more damage.

Question 16

Describe the venous drainage of the oesophagus

Answer 16

upper and middle 3rd - azygos/hemiazygos/accessory hemiazygos. While lower 3rd goes to left gastric vein (portal system)

Question 17

What is the anstamoses between middle and lower thirds of oesophagus?

Answer 17

Portocaval anastamosis

Question 18

Describe the nerve supply of the oesophagus

Answer 18

Left vagus nerve (turns into anterior vagus trunk), right vagus nerve (turns into posterior vagus trunk)

Question 19

What nerve fibres form the oesophageal plexus?

Answer 19

The anterior vagus trunk and the posterior vagus trunk.

Question 20

Name the mediastinal lymph nodes

Answer 20

Superior and inferior tracheobronchial nodes (receives lymph from lungs - metastasis) and the anterior mediastinal lymph nodes (around brachiocephalic veins) and posterior mediastinal lymph nodes (behind heart)

Question 21

Describe the lymphatic drainage of the mediastinal lymph nodes

Answer 21

Posterior mediastinal lymph nodes drain to the paratracheal then to the bronchomediastinal lymph trunk. The anterior mediastinal lymph drains straight to the bronchomedisatinal lymph trunk

Question 22

Describe the lymphatic drainage of the left upper body.

Answer 22

The left jugular lymph trunk (LT), the left subclavian LT and the left bronchomediastinal trunk all drain to the thoracic druct which drains into the left brachiocephalic vein at pirogoffs angle

Question 23

Describe the lymphatic drainage of the right upper body

Answer 23

The right jugular LT, right subclavian LT and the right bronchomediastinal trunk all drain into the right lymphatic duct which drains into the right brachiocephalic vein.

Question 24

Describe the function of the thoracic duct

Answer 24

Carries lymph from all the body except thorax, and UL, neck and head from right side, stating from the cisterna chyli. The pulsation of the aorta promotes lymph flow.

Question 25

What is the clinical significance of the thoracic duct

Answer 25

Lymphatic fluid can leak from the thoracic duct resulting in a chylothorax which is where lymphatic fluid enters the pleural cavity