G4 Mediastinum Flashcards
The superior mediastinum includes these structures:
- Thymus Gland
- SVC and great vv
- Arch of aorta, great aa
- Vagus nn, phrenic nn
- Trachea, esophagus
- Thoracic Duct
Posterior to manubrium, anterior to brachiocephalic vv. Prominent/active in kids before puberty (t cell maturation); inactive/atrophies in adults
Thymus Gland
The ____ vein crosses the trachea anteriorly
L brachiocephalic
The Aortic Arch begins and ends at the same level ____, arches over ____ and ____, gives rise to 3 great aa before descending:
Sternal angle (T4-T5)
L main bronchus
Pulmonary Trunk
Brachiocephalic trunk
L common carotid a.
L subclavian a.
The vagus nerves descend ____ to the root of the lung and provide ____ innervation to the thorax/abdomen
Posterior
Parasympathetic
The phrenic nerves descend ____ to the root of the lung and provide ____ innervation to the diaphragm
Anterior
Somatic
The trachea bifurcates at the ____ limit of the ____ mediastinum. This bifurcation is known as the ____ and it has numerous lymph nodes.
Inferior
Superior
Carina
Foreign bodies are usually aspirated into the ____ because it is shorter, wider, and more vertically oriented.
R main bronchus
The stomach may herniate thru the esophageal hiatus (of the diaphragm). This is known as a ____.
Describe the two types:
Hiatal Hernia
Type I: sliding hiatal hernia- stomach slides freely into thorax
Type II: paraesophageal hernia- often fixed into position risking gastric blood supply
List the major structures of the Posterior Mediastinum:
- Esophagus and esophageal plexus
- Azygos system of vv
- Descending aorta
- Thoracic duct
- Thoracic splanchnic nn
The vagus nn join to form the plexus around esophagus.
The L vagus n forms the ____
The R Vagus n forms the ____
Anterior Vagal trunk
Posterior Vagal trunk
Intercostal vv from R side of thorax drain into ____ which drains into ____.
L thorax drains into ____ which drains into ____.
Azygos v
SVC
Hemiazygos and Accessory hemiazygos vv
Azygos v.
The descending aorta lies just ____ of the esophagus. It gives rise to ____ that supply thorax. It also supplies branches to trachea, bronchi, and esophagus.
Left
Posterior Intercostal aa
Accumulation of lymph in pleural cavity. Results from torn/leaking thoracic duct. Often from lymphoma or trauma during thoracic surgery. A type of pleural effusion visible on chest films.
Chylothorax
The sympathetic trunks have 2 types of branches from ganglia:
- Postganglionic sympathetic to thoracic viscera
2. Preganglionic sympathetic to innervate abdomen (not thorax) (Greater, Lesser, Least Splanchnics)
