Mediastinum and Great Vessels

Front

What is the mediastinum?

Back

Middle space in the thoracic cavity in between the lungs.

Front

List the structures in the mediastinum.

Back

1. Heart & large vessels of thorax 2. Tubes: trachea & esophagus 3. Nerves, lymph nodes & lymph vessels

Front

Describe the boundaries of the mediastinum.

Back

1. Anteriorly: sternum 2. Posteriorly: vertebral column 3. Superiorly: plane of thoracic inlet 4. Inferiorly: diaphragm 5. On each side: lungs & mediastinal pleura

Front

Describe the divisions of the mediastinum.

Back

1. Superior & inferior mediastinum 2. Divided by imaginary plane from sternal angle to T4 vertebra 3. Superior mediastinum: above imaginary plane 4. Inferior mediastinum: below imaginary plane. Subdivision: anterior, middle & posterior.

Front

Describe the boundaries of the superior mediastinum.

Back

1. Anteriorly: manubrium sterni 2. Posteriorly: upper 4 thoracic vertebrae 3. Superiorly: plane of thoracic inlet 4. Inferiorly: imaginary plane from sternal angle & T4 vertebra 5. On each side: mediastinal pleura.

Front

List the contents of the superior mediastinum.

Back

1. Four (4) arteries: a) Aortic arch b) Brachiocephalic artery c) Left common carotid artery d) Left subclavian artery 2. Four (4) veins: a) Rt & Lt brachiocephalic veins b) Upper half SVC c) Left superior intercostal veins 3. Four (4) nerves: a) Phrenic (L & R) b) Cardiac nerve (L & R) c) Vagus nerve (L & R) d) Left recurrent laryngeal nerve 4. Three (3) viscera: a) Esophagus b) Trachea c) Remnant of thymus gland 5. Three (3) muscles: a) Sternohyoid b) Sternothyroid c) Longus colli 6. Lymph nodes and thoracic duct

Front

Describe the boundaries of the anterior mediastinum.

Back

1. Anteriorly: body of the sternum 2. Posteriorly: pericardium 3. Superiorly: Imaginary plane 4. Inferiorly: diaphragm 5. On each side: mediastinal pleura

Front

What are the contents of the anterior mediastinum?

Back

1. Sternopericardial ligaments 2. Lymph nodes with lymphatics 3. Mediastinal branches of the internal thoracic artery 4. Part of the thymus gland 5. Areolar tissue.

Front

Describe the contents of the middle mediastinum.

Back

1. Heart enclosed in the pericardium 2. Arteries: a) Ascending aorta, b) Pulmonary trunk c) Two pulmonary arteries. 3. Veins: a) Lower ½ of the SVC b) Upper part of IVC c) Terminal part of the azygos vein d) Right & left pulmonary veins. 4. Nerves: a) Both phrenic nerves b) Deep cardiac plexus 5. Tubes: a) Bifurcation of trachea b) Right & left main bronchi 6. Lymph nodes: Tracheobronchial LNs

Front

Describe the boundaries of the posterior mediastinum.

Back

1. Anteriorly: a) Pericardium b) Bifurcation of trachea c) Pulmonary vessels d) Diaphragm 2. Posteriorly: Lower 8 thoracic vertebrae & discs 3. On each side: mediastinal pleura