Human Anatomy Vol 1

WALL OF THORAX

Sympathetic chain

Postganglionic fibres from T1 to T5 ganglia

supply heart, lung, aorta and oesophagus

Greater splanchnic nerve

* Lesser splanchnic nerve

Least splanchnic nerve

Fig. 14.13r The thoracic part of the sympathetic trunk and its splanchnic branches

b.

diaphragm; and ends (in the abdomen) mainly

in the coeliac ganglion, and partly in the aortico-

renal ganglion and the suprarenal gland.

The lesser splanchnic neroe is formed by two roots

from ganglia 10 and 11. Its course is similar to

that of the greater splanchnic nerve. It pierces the

crus of the diaphragm, and ends in the coeliac

ganglion (Fig. 14.1a).

The least (lowest) splanchnic nerae (renal neroe) is

tiny. It arises by one root from ganglion 12. It

pierces the corresponding crus of the diaphragm.

The coeliac plexus gives offshoots called superior

mesenteric and inferior mesenteric plexuses.

Their branches supply the intestines and repro-

ductive organs and ends ir-r the renal plexus.

. Cardiac pain is an ischaemic pain caused by
incomplete obstruction of a coronary artery.
Axons of pain fibres conveyed by the sensory
sympathetic cardiac nerves reach thoracic one to
thoracic five segments of spinal cord mostly through
the dorsal root ganglia of the left side. Since these
dorsal root ganglia also receive sensory impulses
from the medial side of arm, forearm and upper part
of front of chest, the pain gets referred to these areas
as depicted in Fig. 18.27.
Though the pain is usually referred to the left side,
it may even be referred to right arm, jaw, epigastrium
or back.

c