Superior mediastinum Flashcards Preview

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Flashcards in Superior mediastinum Deck (16):
1

Superior boundary of superior mediastinum

Superior thoracic aperture (manubrium, 1st rib and costal cartilage, vertebra)

2

Inferior boundary of superior mediastinum

Transverse thoracic plan (sternal angle to vertebral level T4/5)

3

Anterior boundary of superior mediastinum

Manubrium

4

Posterior boundary of superior mediastinum

T1-T4/5 vertebral bodies

5

Lateral boundary of superior mediastinum

Mediastinal pleura

6

Contents of superior mediastinum

Arteries (arch of aorta and branches)
Veins (brachiocephalic veins, superior vena cava)
Trachea
Oesophagus
Thoracic duct
Phrenic and vagus nerves
Thymus gland

7

Thymus gland

Lymphoid organ
Lymph drains through from parasternal, brachiocephalic and tracheobronchial nodes
After puberty atrophies and replaced by fat
Supplied by internal thoracic arteries

8

Arteries in the superior mediastinum

Aortic arch and its 3 branches:
- brachiocephalic trunk
- left common carotid artery
- left subclavian artery

9

Veins in the superior mediastinum

Superior vena cava formed by union of left and right brachiocephalic veins

Each brachiocephalic vein formed by the union of an internal jugular vein and a subclavian vein

10

Ligamentum arteriorsum

Embryological remnant of the ductus arteriosus

11

Ductus arteriosus

Open duct connecting the pulmonary trunk and the arch of the aorta

Important in foetal circulation allowing blood to bypass the immature lungs

Closes at birth and remains in the adult as a ligamentous structure

12

Trachea

Tube c-shaped cartilages

Trachealis muscle runs posteriorly

Runs from larynx to bronchi

13

Oesophagus

Muscular tube

Runs from pharynx to stomach

14

Thoracic duct

Transports lymph to venous system

Receives multiple branches throughout the thorax

Numerous lymph nodes associated with thoracic aorta

15

Phrenic nerves

Originate from the anterior rami of spinal nerves C3, C4, C5

Sole motor supply of diaphragm

1/3 sensory supply to diaphragm

Enter superior mediastinum between brachiocephalic veins and subclavian arteries

Pass anterior to main bronchi

16

Vagus nerves

Cranial so originate from brainstem

Enter superior mediastinum close to but medial to the phrenic nerve

Give rise to recurrent laryngeal branch to supply the larynx

Continue into posterior mediastinum posterior to the main bronchi