THORAX III Flashcards
What are the superior, posterior, anterior, lateral and inferior boundaries of the superior mediastinum?
Superior boundaries: Manubrium, T1, ribs 1
Posterior: T1-T4
Anterior: Manubrium
Lateral: Lungs and mediastinal pleura
Inferior: Transverse thoracic plane (T4/5)
Before entering the root of the right lung, what does the right pulmonary artery pass posterior too?
The ascending aorta and the superior vena cava
Was does the left pulmonary artery run anterior to before entering the left lung root?
The descending thoracic aorta
What side of the body does the azygous vein run in?
The right side of the body
What’s the function of the azygous vein?
To transport deoxygenated blood from the posterior walls of the thorax and abdomen into the superior vena cava
At what level is the azygous vein formed?
T12
What is the azygos vein formed from?
The union of the ascending lumbar vein with the right subcostal vein
What does the azygous vein arch over after ascending in the posterior mediastinum?
The right main bronchus at the root of the right lung
What are the 2 tributaries to the azygous vein?
The hemiazygous vein and the accessory hemiazygous vein
What forms the hemiazygous vein?
The oesophageal and mediastinal tributaries, the common trunk of the left ascending lumbar vein and left subcostal vein, and the lower of the 3 posterior intercostal veins
The hemiazygous vein ascends anterior to the vertebral column before crossing posterior to the aorta, oesophagus and thoracic duct at what vertebral level?
T8
What forms the accessory hemiazygous vein?
Veins from the 4th to 8th intercostal spaces and sometimes by the left bronchial veins
At what level does the accessory hemiazygous vein cross to join the azygous vein?
T7
From what spinal segments does the right phrenic nerve arise?
C3, C4, C5
What does the phrenic nerve provide motor innervation to?
The diaphragm
What does the phrenic nerve provide sensory innervation to?
The central part of the diaphragm, the pericardium and the mediastinal part of the parietal pleura
What vessels does the right phrenic nerve descend lateral to?
The right brachiocephalic vein and the superior vena cava
Does the right phrenic nerve run anterior or posterior to the root of the right lung?
Anterior to the hilum of the right lung
What vessel does the left phrenic nerve run lateral to?
The left subclavian artery
What nerve does the left phrenic nerve cross superficially as it approaches the aortic arch?
The left vagus nerve
Does the left phrenic nerve run anterior or posterior to the root of the left lung?
Anterior
What does phrenic nerve damage lead to?
Diaphragmatic paralysis
What is the sensory innervation by the vagus nerve?
Innervates the skin of the external acoustic meatus and the internal surfaces of the laryngopharynx and larynx. Provides visceral sensation to the heart and abdominal viscera
What’s the special sensory innervation by the vagus nerve?
Provides taste sensation to the epiglottis and the root of the tongue
What is the motor innervation by the vagus nerve?
Provides motor innervation to the majority of the muscles of the pharynx, soft palate and larynx
What’s the parasympathetic innervation by the vagus nerve?
Innervates the smooth muscle of the trachea, bronchi and gastro-intestinal tract and regulates heart rhythm
Where does the vagus nerve originate?
The medulla oblongata of the brainstem
Via what foramen does the vagus nerve exit the cranium?
The jugular foramen
What branch arises from the vagus nerve within the cranium?
The auricular branch