Thoracic cavity - The thorax Flashcards
Identify thoracic cavity and subdivisions
The thoracic cavity is enclosed by the thoracic wall and the diaphragm is divided into:
- Mediastinum
- Pleural cavities
- Pericardial cavity
- Diaphragm
Mediastinum
A thick, flexible, soft tissue partition in the median sagittal position, containing the heart, esophagus, trachea, major blood vessels, and nerves. It is subdivided into the superior mediastinum and inferior mediastinum.
Pleural cavities
Two completely separate cavities surrounding the lungs, lined by the pleura
Pericardial cavity
A space within the middle mediastinum containing the heart, surrounded by the pericardium
Diaphragm
A musculotendinous structure that seals the inferior thoracic aperture, playing a vital role in respiration.
Superior thoracic aperture
The superior thoracic aperture is completely surrounded by skeletal elements and allows structures to pass between the neck and the thorax.
- Trachea
- Esophagus
- Subclavian artery and vein
- Brachiocephalic veins
- Vagus nerve
- Phrenic nerve
- Thoracic duct
- Brachial plexus
Trachea
Passes through the superior thoracic aperture into the mediastinum
Esophagus
A muscular tube that runs posterior to the trachea
Subclavian artery and vein
Cross over rib I as they enter the thorax
Brachiocephalic veins
The left brachiocephalic vein crosses the midline and joins the right brachiocephalic vein to form the superior vena cava
Vagus nerve
Passes posteriorly into the mediastinum
Phrenic nerve
Passes anteriorly through the mediastinum to innervate the diaphragm
Thoracic duct
the largest lymphatic vessel, which drains into the venous system near the left brachiocephalic vein.
Brachial plexus
The proximal parts of the brachial plexus pass through the axillary inlet, adjacent to the superior thoracic aperture
Inferior thoracic aperture
The inferior thoracic aperture is closed by the diaphragm, and structures pass through or posterior to it.
- Aortic hiatus
- Esophageal hiatus
- Caval opening
- Diaphragm
- Abdominal aorta
- Inferior vena cava
- Vagus nerve
Aortic hiatus
Located at vertebral level TXII, allowing passage of the abdominal aorta, thoracic duct, and azygos vein.
Esophageal hiatus
Located at vertebral level TX, allowing the esophagus and vagus nerves to pass into the abdomen.
Caval opening
Located at the vertebral level TVIII, allowing passage of the inferior vena cava
Diaphragm
the musculotendinous structure that separates the thoracic cavity from the abdominal cavity.
Abdominal aorta
Passes posterior to the diaphragm at vertebral level TXII, continuing as the abdominal aorta.
Inferior vena cava
Passes through the caval opening at vertebral level TVIII, returning blood to the right atrium.
Vagus nerve
passes through the esophageal hiatus to contribute to the autonomic innervation of the abdominal organs.
