The Superior and Posterior Mediastinum - gross Flashcards
What are the divisions of the Mediastinum?
- Superior
- Inferior
- Anterior
- Middle
- Posterior
What 6 structures are found in the Superior mediastinum?
- Thymus
- SVC & great vv.
- Arch of aorta & Great aa.
- Vagus nn. & Phrenic nn.
- Trachea & Esophagus
- Thoracic duct
Why is the thymus?
Posterior to manubrium of sternum.
- Lies anterior to brachiocephalic vv.
- Functionally inactive & atrophies in adults.
Where is the thymus?
Posterior to manubrium of sternum.
- Lies anterior to brachiocephalic vv.
- Functionally inactive & atrophies in adults.
L. Branchiocephalic vein crosses _______ anteriorly.
Trachea
L. Brachiocephalic vein crosses _______ anteriorly.
Trachea
At what level does the Aortic arch begin and end?
T4-T5
Aorta arches over ____ & _____.
Bronchus & pulmonary trunk
_____ & _____ pass through the thoracic inlet between a vein and artery.
Vagus Nerves & Phrenic N.
Vagus provides what kind of innervation to thorax and abdomen?
Parasympathetic
Vagus Nerve provides what kind of innervation to thorax and abdomen?
Parasympathetic
______ Descends to poster root of lung.
Vagus
Phrenic Nerve provides what kind innervation to Diaphragm?
Somatic innervation
______ Descends to anterior root of the lung.
Phrenic nerve
_____ Descends immediately anterior to esophagus.
Trachea
Where does the trachea bifurcate (level)?
at inferior limit of superior Mediastinum
T or F, Numerous lymph nodes are found at the carina.
True
What is the carina?
Septum-like structure where R & L main bronchi split.
Which bronchi usually aspirate foreign objects?
The right main bronchus because its shorter, wider, and more vertically orient than left bronchus.
What are the two types of Esophageal Hiatus?
Type I: sliding hiatal hernia
Type II: Paraesophageal hernia
Describe type I esophageal hiatus…
- Stomach slides freely into thorax
- most common
- often asymptomatic
Describe type II esophageal hiatus….
- fundus
- Often fixed in position risking gastric blood supply.
Infection may spread from retropharyngeal space into _______.
Danger Space
What is found in the Posterior Mediastinum?
- Esophagus & esophageal plexus
- Azygous system of vv.
Descending Aorta - Thoracic duct
- thoracic splanchnic nn.
______ joins to form plexus around the esophagus (Esophageal plexus).
Vagus nn.
L. Vagus N. = ?
Anterior Vagal trunk
R. Vagus N. = ?
Posterior vagal trunk
Both Vagal trunks pass through diaphragm with _____.
esophagus
__________ drains intercostal vv from right side of thorax.
Azygous V.
______ & _______ drains left thorax.
Hemiazygos & accessory hemiazygous vv.
______ & _______ drains left thorax.
Hemiazygos & accessory hemiazygous vv.
*Both drain to azygous V.
Where does Azygous V. drain?
Arches over right superior bronchus to drain into SVC
______ lies just L of esophagus.
Descending Aorta
Descending aorta gives rise to what?
- posterior intercostal aa. supplying thorax.
- supplies branches to trachea, bronchi & esophagus.
Where is the thoracic duct?
Posterior to esophagus & anterior to vertebral bodies.
Where is the thoracic duct?
Posterior to esophagus & anterior to vertebral bodies.
*Between azygous v. & descending aorta.
______ Enters the Venous angle between L subclavian V. & Left IJV.
thoracic duct
What does the thoracic duct do?
drains lymph from entire body below diaphragm.
________ is accumulation of lymph in pleural cavity.
chylothorax
________ is accumulation of lymph in pleural cavity.
chylothorax
What causes chylothorax?
Results from torn or leaking thoracic duct.
*Looks like massive white haze in chest cavity of x-ray film.
What are the 2 thoracic branches from ganglia?
1st = postgang. symp. to thoracic viscera.
2nd = preganglionic symp. innervate the abdomen (not thorax)
- grater splanchnic nn.
- lesser splanchnic nn
- least splanchinic nn.
Thoracic Autonomic sympathetic nerves originate from what level?
T1-T5
Thoracic autonomic parasymp. nerves originate from where?
CN X
What 3 nerves commingle to form thoracic plexus of nerves?
- cardiac
- Pulmonary
- Esophageal
