Intercostal arteries

Intercostal arteries
Intercostal spaces,viewed from the left
Details
Vein	Intercostal veins
Supplies	Intercostal musclesandintercostal space
Identifiers
Latin	arteriae intercostales
Anatomical terminology

Theintercostal arteriesare a group ofarteriespassing within anintercostal space(the space between two adjacent ribs). There are 9 anterior and 11 posterior intercostal arteries on each side of the body. The anterior intercostal arteries are branches of the internal thoracic artery and its terminal branch - themusculophrenic artery.The posterior intercostal arteries are branches of the supreme intercostal artery and thoracic aorta.

Each anterior intercostal arteryanastomoseswith the corresponding posterior intercostal artery arising from the thoracicaorta.

Anterior intercostal arteries

Origin

The upper five or six anterior intercostal arteries are branches of theinternal thoracic artery(anterior intercostal branches of internal thoracic artery). The internal thoracic artery then divides into its two terminal branches, one of which - themusculophrenic artery- proceeds to issue anterior intercostal arteries to the remaining 6th, 7th, and 9th intercostal spaces; these diminish in size as the spaces decrease in length.

Course and relations

They are at first situated between thepleuraeand theintercostales interni,and then between the mm. intercostales interni et intimi.

Distribution

They supply theintercostal musclesand, by branches which perforate theintercostales externi,thepectoral musclesand themamma.

Posterior intercostal arteries

There are eleven posterior intercostal arteries on each side. Each artery divides into an anterior and a posterior ramus.

Origin

• The 1st and 2nd posterior intercostal arteries arise from thesupreme intercostal artery,a branch of thecostocervical trunkof thesubclavian artery.The SICA descends vertically. It passes lateral to thecervicothoracic ganglion.It passes in between the pleural cupula, and anterior border of the neck of rib I. It then passes anterior to the necks of ribs II-III.
• The remaining nine arteries arise from (the posterior aspect of) thethoracic aorta.

Course and relations

Each posterior intercostal artery travels along the bottom of the rib alongside its correspondingposterior intercostal veinandintercostal nerve;the vein is superior to the artery, and the nerve is inferior to it. The mnemonic "VAN" is commonly used to recall their order from superior to inferior.

The right aortic intercostals are longer than the left because of the position of the aorta on the left side of the vertebral column; they pass across the bodies of thevertebraebehind theesophagus,thoracic duct,andazygos vein,and are covered by the rightlungandpleura.

The left aortic intercostals run backward on the sides of the vertebrae and are covered by the leftlungandpleura;the upper two vessels are crossed by the leftsuperior intercostal vein,the lower vessels by thehemiazygos vein.

Thesympathetic trunk(opposite the heads of the ribs) andsplanchnic nervespass anterior to the arteries.

See also

• Supreme intercostal vein
• Superior intercostal vein
• Anterior intercostal veins
• Posterior intercostal veins
• Intercostal nerves

References

This article incorporates text in thepublic domainfrompage 584of the 20th edition ofGray's Anatomy(1918)

External links

• Anatomy photo:18:07-0102at the SUNY Downstate Medical Center - "Thoracic wall:Branches of the Internal Thoracic Artery "
• http://www.instantanatomy.net/thorax/vessels/aupperintercostalarteries.html
• Anatomy figure: 21:06-06at Human Anatomy Online, SUNY Downstate Medical Center - "Branches of the ascending aorta, arch of the aorta, and the descending aorta."
• thoraxlesson5at The Anatomy Lesson by Wesley Norman (Georgetown University) (paravertebralregion)
• Atlas image: abdo_wall70at the University of Michigan Health System