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CHAPTER 3
Branches
The Thorax: Part II—The Thoracic Cavity
1.
Gray rami communicantes go to all the thoracic spinal
sweat glands, and arrector pili muscles of the skin.
the branches of the spinal nerves to the blood vessels,
nerves. The postganglionic fibers are distributed through
2.
The first five ganglia give postganglionic fibers to the
heart, aorta, lungs, and esophagus.
3.
The lower eight ganglia mainly give preganglionic fib
of these nerves in the abdomen, see page 224.
arises from ganglion 12. For details of the distribution
lowest splanchnic nerve
ganglia 10 and 11, and the
arises from
lesser splanchnic nerve
ganglia 5 to 9, the
arises from
greater splanchnic nerve
diaphragm. The
They enter the abdomen by piercing the crura of the
nerves (Fig. 3.15) and supply the abdominal viscera.
ers, which are grouped together to form the splanchnic
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pathectomy causes vasodilatation of the arterioles in the
ganglia can be performed to increase the blood flow to the
Preganglionic sympathectomy of the 2nd and 3rd thoracic
Sympathetic Trunk in the Treatment of Raynaud
Disease
fingers for such conditions as Raynaud disease. The sym-
upper
A high spinal anesthetic may block the preganglionic sympa
limb.
Spinal Anesthesia and the Sympathetic Nervous
System
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thetic fibers passing out from the lower thoracic segments of
the spinal cord. This produces temporary vasodilatation below
this level, with a consequent fall in blood pressure.
C L I N I C A L N O T E S
Esophagus
and internal thoracic arteries.
The blood supply of the thymus is from the inferior thyroid
site for development of T (thymic) lymphocytes.
involution. It has a pink, lobulated appearance and is the
continues to grow until puberty but thereafter undergoes
of the great vessels into the root of the neck. The thymus
may extend up through the superior mediastinum in front
largest size relative to the size of the body, at which time it
anterior mediastinum. In the newborn infant, it reaches its
lying between the sternum and the pericardium in the
The thymus is a flattened, bilobed structure (see Fig. 3.6)
esophagus is surrounded by the esophageal nerve plexus.
thetic trunks. In the lower part of its thoracic course, the
thetic efferent and afferent fibers via the vagi and sympa
The esophagus is supplied by parasympathetic and sympa
and the celiac nodes (see Fig. 3.26).
lower third into nodes along the left gastric blood vessels
the superior and posterior mediastinal nodes, and from the
into the deep cervical nodes, from the middle third into
Lymph vessels from the upper third of the esophagus drain
Lymph Drainage of the Esophagus
gastric vein, a tributary of the portal vein.
into the azygos veins, and from the lower third into the left
drain into the inferior thyroid veins, from the middle third
from the left gastric artery. The veins from the upper third
descending thoracic aorta, and the lower third by branches
rior thyroid artery, the middle third by branches from the
The upper third of the esophagus is supplied by the infe
diaphragm posteriorly.
the left lobe of the liver anteriorly and to the left crus of the
0.5 in. (1.3 cm) and then enters the stomach. It is related to
In the abdomen, the esophagus descends for about
form of a sling.
crus of the diaphragm pass around the esophagus in the
blood vessels, and lymphatic vessels. Fibers from the right
accompanied by the two vagi, branches of the left gastric
terior. At the opening in the diaphragm, the esophagus is
lies anterior to the esophagus, and the right vagus lies pos
The left vagus
esophageal plexus.
thetic nerves to form the
nerves leave the pulmonary plexus and join with sympa
Inferiorly to the level of the roots of the lungs, the vagus
thoracic duct, and the mediastinal pleura (Fig. 3.15)
The left subclavian artery, the aortic arch, the
Left side:
of the azygos vein (see Fig. 3.15)
The mediastinal pleura and the terminal part
Right side:
aorta (Figs. 3.6 and 3.39)
arteries; and, at its lower end, the descending thoracic
racic duct; the azygos veins; the right posterior intercostal
The bodies of the thoracic vertebrae; the tho
Posteriorly:
from the left atrium (Figs. 3.6 and 3.39)
it; and the pericardium, which separates the esophagus
geal nerve; the left principal bronchus, which constricts
The trachea and the left recurrent laryn
Anteriorly:
above downward are as follows:
The relations of the thoracic part of the esophagus from
gus over to the midline (Fig. 3.6).
level of the sternal angle, the aortic arch pushes the esopha
the superior and then the posterior mediastinum. At the
In the thorax, it passes downward and to the left through
the recurrent laryngeal nerves (see page 639).
gland; and anteriorly, it is in contact with the trachea and
column; laterally, it is related to the lobes of the thyroid
In the neck, the esophagus lies in front of the vertebral
tebra to join the stomach (Fig. 3.9).
through the diaphragm at the level of the 10th thoracic ver
the pharynx opposite the sixth cervical vertebra. It passes
long that is continuous above with the laryngeal part of
The esophagus is a tubular structure about 10 in. (25 cm)
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Blood Supply of the Esophagus
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Nerve Supply of the Esophagus
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Thymus
Blood Supply