ANA 202 WK 10
ANA 202 WK 10
ANA 202 WK 10
Week 10
Intercostal Arteries and Veins
hemiazygos)
• Veins from the 9th to the 11th end in the hemiazygos
vein.
Azygos
The azygos Veins
veins consist of the main azygos
vein, the inferior hemiazygos vein, and the
superior hemiazygos vein. They drain blood
from the posterior parts of the intercostal
spaces, the posterior abdominal wall, the
pericardium, the diaphragm, the bronchi, and
the esophagus
Azygos Vein
• The origin of the azygos vein is variable. It is often
formed by the union of the right ascending lumbar vein
and the right subcostal vein or it may arises from the
inferior vena cava
• It ascends through the aortic opening in the diaphragm
on the right side of the aorta to the level of the fifth
thoracic vertebra. Here it arches forward above the
root of the right lung to empty into the superior vena
cava
• Tributaries,
1. The eight lower right intercostal veins
2. The right superior intercostal vein
3. The superior and inferior hemiazygos veins
4. Mediastinal veins.
Inferior Hemiazygos Vein
• The inferior hemiazygos vein is often formed by the
union of the left ascending lumbar vein and the left
subcostal vein.
• At about the level of the eighth thoracic vertebra turns
to the right and joins the azygos vein
Tributaries
1. Lower left intercostal veins (from 9th to 11th )
2. Mediastinal veins.
Superior Hemiazygos Vein
• The superior hemiazygos vein is formed by the union
of the fourth to the eighth intercostal veins.
• It joins the azygos vein at the level of the
seventh thoracic vertebra
Anterior intercostal arteries
• The anterior intercostal arteries of the first six
spaces are branches of the internal thoracic
artery and which arises from the first part of the
subclavian artery.
• The anterior intercostal arteries of the lower
spaces are branches of the musculophrenic
artery, one of the terminal branches of the
internal thoracic artery.
Anterior intercostal veins
• the anterior intercostal veins drain forward
into the internal thoracic and
musculophrenic veins
Internal thoracic artery
• The internal thoracic artery supplies the
anterior wall of the body from the clavicle to the
umbilicus.
• Beginning It is a branch of the first part of the
subclavian artery in the neck.
• Course It descends vertically on the pleura
behind the costal cartilages, a fingerbreadth
lateral to the sternum,
• Termination it ends in the 6th intercostal space
by dividing into the superior epigastric and
musculophrenic arteries.
Branches of internal thoracic
• artery
Two anterior intercostal arteries for the upper six
intercostal spaces
• Perforating arteries which accompany the terminal
branches of the corresponding intercostal nerves
• The pericardiacophrenic artery which accompanies
the phrenic nerve and supplies the pericardium
• Mediastinal arteries to the contents of the anterior
mediastinum (e.g., the thymus)
• The superior epigastric artery which enters the rectus
sheath of the anterior abdominal wall and supplies the
rectus muscle as far as the umbilicus
• The musculophrenic artery which runs around the
costal margin of the diaphragm and supplies the lower
intercostal spaces and the diaphragm
Internal Thoracic
• The Vein
internal thoracic vein accompanies
internal thoracic artery and drains into the
brachiocephalic vein on each side. the
Lymph Drainage of the Thoracic Wall
• The lymph drainage of the skin of the anterior
chest wall passes to the anterior axillary lymph
nodes.
• The lymph drainage of the skin of the
posterior chest wall passes to the posterior
axillary nodes.
• The lymph drainage of the intercostal spaces
passes forward to the internal thoracic nodes,
situated along the internal thoracic artery, and
posteriorly to the posterior intercostal nodes
and the para-aortic nodes in the posterior
mediastinum.