CVR session 3A- Posterior mediastinum

Question 1

what does the posterior mediastinum include?

Answer 1

descending aorta, azygos veins, oesophagus, thoracic duct, sympathetic trunk and splanchnic nerves, posterior vessels and nerves

Question 2

descending aorta - what it branches into? what level does it pass through diaphragm?

Answer 2

moves through posterior mediastinum and gives rises to many branches:
posterior intercostal arteries
bronchial arteries
oesophageal branches
pericardial branches
phrenic branches

it then passes through the diaphragm at T12 vertebrae level (after known as abdominal aorta)

Question 3

azygos veins- describe purpose? where they receive blood from? rough location?

Answer 3

drains blood from the posterior thoracic wall and drain into superior vena cava. Receives blood from posterior intercostal veins, oesophageal veins and bronchial veins. They are mainly sit on right hand side of vertebral bodies. There are shorter and smaller hemiazygous veins (ACCESSORY) on left side of vertebral bodies and one or more veins connecting the above veins.

Question 4

Oesophagus - location? arteries and veins? what level passes through diaphragm? type of mucle in wall?

Answer 4

Located to the right and posterior of the aorta. Supplied by oesophageal arteries from decedning arota and drained by oesophageal veins that go into azugos system. Smooth muscle in wall (under autonomic controll). Passes through oesophageal hiatus in diaphragm at T10

Question 5

thoracic duct - where is it located? where does lymph from lower body drain? where else drains into it? where does it end? where does it drain into venous system?

Answer 5

thoracic duct returns majority of bodys lymph to venous system. Located between oesophagus and the aorta. Lymph from the lower limbs. pelvis and abdomen drain into cisterna chyli in abdomen (gives rise to thoracic duct). Once in thorax duct receives lymph from intercostal spaces by lymph nodes and system of nodes up to neck receiving from left side of head and neck and upper left limb. Ends by opening into venous system at junction between left internal jugular vein and left subclavian vein. Right side of head and neck drain into lymphatic ducts which enters venous system at junction between right internal jugular and right subclavian.

Question 6

Sympathetic trunk