Human Anatomy Vol 1

Trachea

Brachiocephalic

artery

Right Atrium

brachiocephalic

vetn

Superior

vena cava

Ascending

aorta

THORAX

Contenls

1 chea and oesophagus"
2 Muscles: Origins of (i) sternohyoid, (ii) sterno-
thyroid, (iii) lower ends of longus colli.
3 Arteries: (i) Arch of aorta, (ii) brachiocephalic artery,
(iii) left common carotid artery, (iv) left subclavian
artery (Fig.17.2).
4 Veins: (i) Right and left brachiocephalic veins,
(ii) upper half of the superior vena cava, (iii) left
superior intercostal vein.
5 raes: (i) Vagus, (ii) phrenic, (iii) cardiac nerves of
both sides, (iv) left recurrent laryngeal nerve.
6 Tlrymus.
7 Thorocic furct.
8 Lymph nodes: Paratracheal, brachiocephalic, and
tracheobronchial.

8o*ndcries

Anteriorly: Body of stermrm.

P osteriarly : Pericardium.

Superiorly: Imaginary plane separating the superior

mediastinum from the inferior mediastinum.

Inferiorly: Superior surface of diaphragm.

On each sitle: Mediastinal pleura.

Confeatfs

1 Sternopericardial ligaments (Fig. 17.1).

2 Lymph nodes with lymphatics.

3 Small mediastinal branches of the internal thoracic

artery.

4 The lowest part of the thymus.

5 Areolar tissue.

Middle Mediostinum

Middle mediastinum is occupied by the pericardium

and its contents, along with the phrenic nerves and the

pericardiacophrenic vessels.

Forun rfes

Anteriorly : Stemopericardial ligaments.

Posteriorly: Oesophagus, descending thoracic aorla,

azygosvein(see Figs 15.1 and 15.2)

On each side: Mediastinal pleura.

Confenfs

I Heart enclosed in pericarditm (Fig. L7.2)

2 Arteries: (i) Ascending aorta, (ii) pulmonary trunk,

(iii) two pulmonary arteries (Fig. 17.3)

3 Ve.ins: (i) Lower half of the superior vena cava, (ii)

terminal part of the azygos vein, (iii) right and left

pulmonary veins.

Azygos vein

Oesophagus

Trachea

Arch of aorta

Left pulmonary

artery '

Pulmonary veins

Pulmonary trunk

Fig. 17.3: Some structures presenl in superior, middle and

posterior mediastinum

Oesophagus

Left common

carotid artery

Left subclavian

artery

Left

brachiocephalic

vern

Arch of aorta

Left pulmonary

aiety

Pulmonary trunk

Pericardium

Fig.17.2: Arrangement of the large structures in the superior

mediastinum. Note the relationship of superior vena cava,

ascending aorta and pulmonary trunk to each other in the middle

mediastinum, i.e. wiihin the pericardium. The bronchi are not

shown

The inferior mediastinum is divided into anterior,

middle and posterior mediastina. These are as follows:

Anleilor Mediostinum

Anterior mediastinum is a very narrow space in front

of the pericardium, overlapped by the thin anterior

borders of both lungs. It is continuous through the

superior mediastinum with the pretracheal space of the

neck.