Human Anatomy Vol 1

THORAX

Right brachiocephalic vein

Superior vena cava

with those of the tracheobronchial and brachiocephalic
nodes to form the bronchomediastinal trunk, which joins
the right lymphatic trunk on the right side and the thoracic
duct on the left side.
Lymphatibs from the posterior part of the space pass
to the posterior intercostal nodes which lie on the heads
and necks of the ribs. Their efferents in the lower four
spaces unite to form a trunkwhich descends and opens
into the clsferna chyli.The efferents from the upper spaces
drain into the thoracic duct on the left side and into
bronchomediastinal trunkon the right side (see Fig.20.7).

INIERNAT IHORACIC ARTERY

Origin

Internal thoracic artery arises from the inferior aspect
of the first part of. the subclavian artery opposite the
thyrocervical trunk. The origin lies 2 cm above the
sternal end of the clavicle (Fig. 1a.11).

Beginning, Course ond Terminolion

Intemal thoracic artery arises from lower border of 1st
part of subclavian artery. It descends medially and
downwards behind sternal end of clavicle, and 1st
costal cartilage. Runs vertically downwards2 cm from
lateral border of stemum till 6th intercostal space.
The artery terminates in the sixth intercostal space
by dividing into the superior epigastric and musculo-
phrenic arteries.
The artery is accompanied by two venae comitantes
which unite at the level of the third costal cartilage to
form the internal thoracic or internal mammary vein.

Left brachiocephalic vein

1

Left superior intercostal vein

First rib

Scalenus anterior muscle

Vertebral artery

Thyrocervical trunk

Right common carotid

artery

Right subclavian artery

Brachiocephalic artery

Fig. 14.11: The origin of the internal thoracic artery from the

first part of the subclavian artery

The vein runs upwards along the medial side of the

artery to end in the brachiocephalic vein at the inlet of

the thorax.

A chain of lymph nodes lies along the artery.

Relolions

Aboae the first costal cartilage it runs downwards,

forwards and medially, behind:

1 The sternal end of the clavicle.

2 The internal jugular vein.

3 The brachiocephalic vein

4 The first costal cartilage.

5 The phrenic nerve. It descends in front of the cervical

pleura.

Azygos vein

Right superior intercostal vein

Posterior intercostal veins Accessory hemiazygos vein

Hemiazygos vein

Right subcostal

Lumbar azygos

Left subcostal vein

Left ascending lumbar vein

lnferior vena cava

Right ascending lurnbar vein

Right renal vein

Fig. 14.10: The veins on the posterior thoracic wall. Note the drainage of the posterior intercostal veins

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