The intercostal arteries are a group of
arteries
An artery () is a blood vessel in humans and most other animals that takes oxygenated blood away from the heart in the systemic circulation to one or more parts of the body. Exceptions that carry deoxygenated blood are the pulmonary arteries in ...
passing within an
intercostal 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
The internal thoracic artery (ITA), also known as the internal mammary artery, is an artery that supplies the anterior chest wall and the breasts. It is a paired artery, with one running along each side of the sternum, to continue after its bifurc ...
and its terminal branchthe
musculophrenic artery. The posterior intercostal arteries are branches of the supreme intercostal artery and
thoracic aorta
The thoracic aorta is a part of the aorta located in the thorax. It is a continuation of the aortic arch. It is located within the posterior mediastinal cavity, but frequently bulges into the left pleural cavity. The descending thoracic aorta be ...
.
Each anterior intercostal artery
anastomoses
An anastomosis (, : anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf#Veins, leaf veins, or streams. Such a connection may be ...
with the corresponding posterior intercostal artery arising from the thoracic aorta.
Anterior intercostal arteries
Origin
The upper six anterior intercostal arteries are branches of the
internal thoracic artery
The internal thoracic artery (ITA), also known as the internal mammary artery, is an artery that supplies the anterior chest wall and the breasts. It is a paired artery, with one running along each side of the sternum, to continue after its bifurc ...
(anterior intercostal branches of internal thoracic artery). The internal thoracic artery then divides into its two terminal branches, one of which - the
musculophrenic artery - proceeds to issue anterior intercostal arteries to the remaining 7th, 8th, and 9th intercostal spaces; these diminish in size as the spaces decrease in length.
Course and relations
They are at first situated between the
pleurae
The pleurae (: pleura) are the two flattened closed sacs filled with pleural fluid, each ensheathing each lung and lining their surrounding tissues, locally appearing as two opposing layers of serous membrane separating the lungs from the media ...
and the
intercostales interni, and then between the mm. intercostales interni et intimi.
Distribution
They supply the
intercostal muscles
The intercostal muscles comprise many different groups of muscles that run between the ribs, and help form and move the chest wall. The intercostal muscles are mainly involved in the mechanical aspect of breathing by helping expand and shrink th ...
and, by branches which perforate the
intercostales externi, the
pectoral muscles and the
mamma.
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 the supreme intercostal artery, a branch of the
costocervical trunk of the
subclavian artery. The SICA descends vertically. It passes lateral to the
cervicothoracic 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) the
thoracic aorta
The thoracic aorta is a part of the aorta located in the thorax. It is a continuation of the aortic arch. It is located within the posterior mediastinal cavity, but frequently bulges into the left pleural cavity. The descending thoracic aorta be ...
.
Course and relations
Each posterior intercostal artery travels along the bottom of the rib alongside its corresponding
posterior intercostal vein and
intercostal 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 the
vertebrae
Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal ...
behind the
esophagus
The esophagus (American English), oesophagus (British English), or œsophagus (Œ, archaic spelling) (American and British English spelling differences#ae and oe, see spelling difference) all ; : ((o)e)(œ)sophagi or ((o)e)(œ)sophaguses), c ...
,
thoracic duct
In human anatomy, the thoracic duct (also known as the ''left lymphatic duct'', ''alimentary duct'', ''chyliferous duct'', and ''Van Hoorne's canal'') is the larger of the two lymph ducts of the lymphatic system (the other being the right lymph ...
, and
azygos vein, and are covered by the right
lung
The lungs are the primary Organ (biology), organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the Vertebral column, backbone on either side of the heart. Their ...
and
pleura
The pleurae (: pleura) are the two flattened closed sacs filled with pleural fluid, each ensheathing each lung and lining their surrounding tissues, locally appearing as two opposing layers of serous membrane separating the lungs from the med ...
.
The left aortic intercostals run backward on the sides of the vertebrae and are covered by the left
lung
The lungs are the primary Organ (biology), organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the Vertebral column, backbone on either side of the heart. Their ...
and
pleura
The pleurae (: pleura) are the two flattened closed sacs filled with pleural fluid, each ensheathing each lung and lining their surrounding tissues, locally appearing as two opposing layers of serous membrane separating the lungs from the med ...
; the upper two vessels are crossed by the left
superior intercostal vein, the lower vessels by the
hemiazygos vein.
The
sympathetic trunk (opposite the heads of the ribs) and
splanchnic nerves pass anterior to the arteries.
See also
*
Supreme intercostal vein
*
Superior intercostal vein
*
Anterior intercostal veins
*
Posterior intercostal veins
*
Intercostal nerves
The intercostal nerves are part of the somatic nervous system, and arise from the anterior rami of the thoracic spinal nerves from T1 to T11. The intercostal nerves are distributed chiefly to the thoracic pleura and abdominal peritoneum, and dif ...
References
External links
* - "
Thoracic wall
The thoracic wall or chest wall is the boundary of the thoracic cavity.
Structure
The bony skeletal part of the thoracic wall is the rib cage, and the rest is made up of muscle, skin, and fasciae.
The chest wall has 10 layers, namely (from su ...
: Branches of the Internal Thoracic Artery"
* http://www.instantanatomy.net/thorax/vessels/aupperintercostalarteries.html
* - "Branches of the ascending aorta, arch of the aorta, and the descending aorta."
* ()
*
{{Authority control
Arteries of the thorax
Medical mnemonics