Superior thoracic aperture
The superior thoracic aperture, also known as the thoracic inlet or outlet, connects the root of the neck with the thorax.
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Gross anatomy
The superior thoracic aperture is kidney-shaped and lies in an oblique transverse plane, tilted anteroinferiorly to posterosuperiorly. It is roughly 10 cm in transverse dimension and 5 cm in AP dimension.
Boundaries
- posteriorly: T1 vertebral body and costovertebral joints
- laterally: first ribs and their costal cartilages
- anteriorly: superior border of the manubrium
Contents
The list of structures that pass through the superior thoracic aperture is long and can be divided into five groups: midline, bilateral, posteriorly, and asymmetric left and right.
- midline from anterior to posterior
- sternohyoid and sternothyroid muscles
- thymic remnants
- inferior thyroid veins
- trachea
- tracheo-esophageal sulcus containing recurrent laryngeal nerves
- esophagus
- thoracic duct displaced to the left
- longus colli muscles
- anterior longitudinal ligament
- laterally on both sides
- posteriorly from medial to lateral
- sympathetic trunk
- supreme intercostal vein
- superior intercostal artery
- ventral ramus of the first thoracic nerve
- on the left:
- left common carotid artery
- left subclavian artery
- left vagus nerve, between left common carotid and left subclavian arteries
- left brachiocephalic vein
- left phrenic nerve
- on the right
- brachiocephalic trunk
- right vagus nerve, lateral to the brachiocephalic trunk
- right brachiocephalic vein
- right phrenic nerve, lateral to the right brachiocephalic vein
Variants
Variant structures that course through include:
- left vertebral artery from the aortic arch
- left brachiocephalic trunk
- right common carotid artery
- right subclavian artery
- right-sided thoracic duct
Related pathology
Related Radiopaedia articles
Anatomy: Thoracic
- thoracic skeleton
- thoracic cage
- thoracic spine
- articulations
- muscles of the thorax
- diaphragm
- intercostal space
- intercostal muscles
- variant anatomy
- spaces of the thorax
- thoracic viscera
- tracheobronchial tree
-
lungs
-
bronchopulmonary segmental anatomy (Boyden Classification) (mnemonic)
- left lung
- right lung
- variant anatomy
- lung parenchyma
- hilum
- pleura
-
bronchopulmonary segmental anatomy (Boyden Classification) (mnemonic)
-
heart
- cardiac chambers
- heart valves
- pectinate muscles
- cardiac fibrous skeleton
-
coronary arteries
- coronary arterial dominance
- myocardial segments
-
left main coronary artery (LMCA)
- ramus intermedius artery (RI)
-
circumflex artery (LCx)
- obtuse marginal branches (OM1, OM2, etc))
- Kugel's artery
-
left anterior descending artery (LAD)
- diagonal branches (D1, D2, etc)
- septal perforators (S1, S2, etc)
-
right coronary artery (RCA)
- conus artery
- sinoatrial nodal artery
- acute marginal branches (AM1, AM2, etc)
- inferior interventricular artery (PDA)
- posterior left ventricular artery (PLV)
- congenital anomalies
- innervation of the heart
- fetal circulation
-
pericardium
- pericardial space
- oblique pericardial sinus
- transverse pericardial sinus
-
pericardial recesses
- aortic recesses
- pulmonic recesses
- postcaval recess
- pulmonary venous recesses
- pericardial ligaments
- epicardial fat pad
- esophagus
- thymus
- breast
- blood supply of the thorax
- arteries
- veins
- superior vena cava (SVC)
- inferior vena cava (IVC)
-
coronary veins
- cardiac veins which drain into the coronary sinus
- great cardiac vein
- middle cardiac vein
- small cardiac vein
- posterior vein of the left ventricle
- vein of Marshall (oblique vein of the left atrium)
- anterior cardiac veins
- venae cordis minimae (smallest cardiac veins or thebesian veins)
- cardiac veins which drain into the coronary sinus
- pulmonary veins
- thoracoepigastric vein
- lymphatics
- innervation of the thorax