Human Anatomy Vol 1

THORAX

Aftery

INTEBNAL THORACIC

(see Figs 14.11

and 21.7)

Pericardiacophrenic

artery

Mediastinal arteries

Two anterior intercostal

arteries

Perforating arteries

Superior epigastric

anery

Musculophrenic

anery

Ascending Aorto

(see Fig. 19.2)

ARCH OF AORTA

(see Fig. 19.2)

Brachiocephalic artery

Left common carotid

artery

Left subclavian artery

DESCENDING

THORACIC AORTA

(see Fig. 14.8)

: Tebb A2.2 Arteries of thorax

Origin, course and termination

Arises from inferior aspect of 1st part of subclavian

artery. lts origin lies^2 cm above the sternal end of the

clavicle. lt runs downwards, fonarards and medially

behind the clavicle and behind the 1-6 costal

cartilages and 1-5 intercostal spaces to terminate in

the 6th intercostal space by dividing into superior

epigastric and musculophrenic arteries

Branch of internal thoracic artery

Small branches of internal thoracic artery

Two arteries each arise in 1-6 upper intercostal

spaces from internal thoracic

Arise from internal thoracic artery in 2nd, 3rd and 4th

spaces

Terminal branch of internal thoracic artery. Enters the

rectus sheath and ends by anastomosing with inferior

epigastric artery, a branch of external iliac artery

This is also the terminal branch of internal thoracic

artery. Ends by giving 2 anterior intercostal arteries in

7-9 intercostal spaces and by supplying the thoraco-

abdominal diaphragm

Arise from the upper end of left ventricle. lt is about

5 cm long and is enclosed in the pericardium. lt runs

upwards, forwards and to the right and continues as the

arch of aorta at the sternal end of upper border of 2nd

right costal cartilage. At the root of aorta, there are three

dilatations of the vessel wall called the aortic sinuses.

These are anterior, left posterior and right posterior

It begins behind the upper border of 2nd right sterno-

chondral joint. Runs upwards, backwards and to left

across the left side of bifurcation of trachea. Then it

passes behind the left bronchus and on the left side

of body of T4 vertebra by becoming continuous with

the descending thoracic aofta

1st branch of arch of aorta. Runs upwards and soon

divides into right common carotid and right subclavian

arteries

It runs upwards on the left side of trachea and at upper

border of thyroid cartilage. The artery ends by dividing

into internal carotid and external carotid arteries

It is the last branch of arch of aorta. Buns to left in the

root of neck behind scalenus anterior muscle, then on

the upper sudace of 1st rib. At the outer border of 1st

rib, it continues as the axillary artery

Begins on the left side of the lower border of body of

T4 vertebra. Descends with inclination to right and

ends at the lower border olf12 vertebra by

continuing as abdominal aorta

Area of distribution

It supplies pericardium, thymus, upper six

intercostal spaces in their anterior parts,

mammary gland, rectus sheath and also

7-9 intercostal spaces. Thus it supplies

anterior thoracic and anterior abdominal

walls from the clavicle to the umbilicus

Supplies fibrous and parietal layer of serous

pericardia and the diaphragm

Supply thymus and fat in the mediastinum

Supply muscles of the 1{ intercostal spaces

and parietal pleura

They are large enough to supply the

mammary gland

Supplies the aponeuroses which form the

rectus sheath, including the rectus

abdominis.

Supplies the muscles of anterior parts of 7-9

intercostal spaces, and the muscle fibres of

the thoracoabdominal diaPhragm

Supplies the hearl musculature with the help

of right coronary and left coronary arteries,

described later.

Through its three branches, namely brachio-

cephalic, left common carotid and left

subclavian arteries, arch of aorta supplies

part of brain, head, neck and upper limb

Through these two branches part of the right

half of brain, head, neck are supplied. The

distribution of 2 branches on right side is

same as on the left side

The two branches supply brain, structures

in the head and neck

Gives branches which supply parl of brain,

part of thyroid gland, muscles around

scapula, 1st and 2nd posterior intercostal

spaces

3-11 posterior intercostal spaces, subcostal

area, lung tissue, oesophagus, pericardium,

mediastinum and diaPhragm

Contd...