The intercostal arteries are a group of

arteries An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pu ...

that supply the area between the

ribs The rib cage, as an enclosure that comprises the ribs, vertebral column and sternum in the thorax of most vertebrates, protects vital organs such as the heart, lungs and great vessels. The sternum, together known as the thoracic cage, is a semi- ...

("costae"), called the intercostal space. The highest intercostal artery (supreme intercostal artery or superior intercostal artery) is an artery in the human body that usually gives rise to the first and second posterior intercostal arteries, which supply blood to their corresponding intercostal space. It usually arises from the

costocervical trunk The costocervical trunk arises from the upper and back part of the second part of subclavian artery, behind the scalenus anterior on the right side, and medial to that muscle on the left side. Passing backward, it splits into the deep cervical ...

, which is a branch of the

subclavian artery In human anatomy, the subclavian arteries are paired major arteries of the upper thorax, below the clavicle. They receive blood from the aortic arch. The left subclavian artery supplies blood to the left arm and the right subclavian artery suppl ...

. Some anatomists may contend that there is no supreme intercostal artery, only a supreme intercostal vein. The anterior intercostal branches of internal thoracic artery supply the upper five or six

intercostal spaces The intercostal space (ICS) is the anatomic space between two ribs (Lat. costa). Since there are 12 ribs on each side, there are 11 intercostal spaces, each numbered for the rib superior to it. Structures in intercostal space * several kind ...

. The

internal thoracic artery In human anatomy, the internal thoracic artery (ITA), previously commonly known as the internal mammary artery (a name still common among surgeons), is an artery that supplies the anterior chest wall and the breasts. It is a paired artery, with one ...

(previously called as internal mammary artery) then divides into the

superior epigastric artery In human anatomy, the superior epigastric artery is a blood vessel that carries oxygenated blood to the abdominal wall, and upper rectus abdominis muscle. It is a branch of the internal thoracic artery. It enters the rectus sheath to desce ...

and musculophrenic artery. The latter gives out the remaining anterior intercostal branches. Two in number in each space, these small vessels pass lateralward, one lying near the lower margin of the

rib In vertebrate anatomy, ribs ( la, costae) are the long curved bones which form the rib cage, part of the axial skeleton. In most tetrapods, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the ches ...

above, and the other near the upper margin of the rib below, and anastomose with the posterior intercostal arteries from the thoracic

aorta The aorta ( ) is the main and largest artery in the human body, originating from the left ventricle of the heart and extending down to the abdomen, where it splits into two smaller arteries (the common iliac arteries). The aorta distributes o ...

. They are at first situated between the

pleurae The pulmonary pleurae (''sing.'' pleura) are the two opposing layers of serous membrane overlying the lungs and the inside of the surrounding chest walls. The inner pleura, called the visceral pleura, covers the surface of each lung and dips be ...

and the intercostales interni, and then between the intercostales interni and innermost. They supply the

intercostal muscles Intercostal muscles are 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 the size of ...

and, by branches which perforate the

intercostales externi The external intercostal muscles, or external intercostals (Intercostales externi) are eleven in number on both sides. Structure The muscles extend from the tubercles of the ribs behind, to the cartilages of the ribs in front, where they en ...

, the pectoral muscles and the mamma. The musculophrenic artery arises from the

, directed obliquely downward and laterally, behind the

cartilage Cartilage is a resilient and smooth type of connective tissue. In tetrapods, it covers and protects the ends of long bones at the joints as articular cartilage, and is a structural component of many body parts including the rib cage, the neck ...

s of the false ribs; it perforates the

diaphragm Diaphragm may refer to: Anatomy * Thoracic diaphragm, a thin sheet of muscle between the thorax and the abdomen * Pelvic diaphragm or pelvic floor, a pelvic structure * Urogenital diaphragm or triangular ligament, a pelvic structure Other * Diap ...

at the eighth or ninth costal cartilage, and ends, considerably reduced in size, opposite the last intercostal space. It gives off intercostal branches to the seventh, eighth, and ninth intercostal spaces; these diminish in size as the spaces decrease in length, and are distributed in a manner precisely similar to the intercostal arteries from the

. The musculophrenic artery also gives branches to the lower part of the

pericardium The pericardium, also called pericardial sac, is a double-walled sac containing the heart and the roots of the great vessels. It has two layers, an outer layer made of strong connective tissue (fibrous pericardium), and an inner layer made ...

, and others which run backward to the

, and downward to the abdominal muscles. The posterior intercostal arteries are arteries that supply blood to the intercostal spaces. There are eleven posterior intercostal arteries on each side. * The 1st and 2nd posterior intercostal arteries arise from the supreme intercostal artery, a branch of the

of the

. * The lower nine arteries are the ''aortic intercostals'', so called because they arise from the back of the thoracic aorta. 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 The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristi ...

behind the

esophagus The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to t ...

thoracic duct In human anatomy, the thoracic duct is the larger of the two lymph ducts of the lymphatic system. It is also known as the ''left lymphatic duct'', ''alimentary duct'', ''chyliferous duct'', and ''Van Hoorne's canal''. The other duct is the rig ...

, and

azygos vein The azygos vein is a vein running up the right side of the thoracic vertebral column draining itself towards the superior vena cava. It connects the systems of superior vena cava and inferior vena cava and can provide an alternative path for blo ...

, and are covered by the right

lung The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of ...

and

pleura The pulmonary pleurae (''sing.'' pleura) are the two opposing layers of serous membrane overlying the lungs and the inside of the surrounding chest walls. The inner pleura, called the visceral pleura, covers the surface of each lung and dips b ...

. The left aortic intercostals run backward on the sides of the vertebrae and are covered by the left

and

; the upper two vessels are crossed by the left

superior intercostal vein The superior intercostal veins are two veins that drain the 2nd, 3rd, and 4th intercostal spaces, one vein for each side of the body. Right superior intercostal vein The right superior intercostal vein drains the 2nd, 3rd, and 4th posterior inter ...

, the lower vessels by the hemiazygos vein. Opposite the heads of the ribs, the

sympathetic trunk The sympathetic trunks (sympathetic chain, gangliated cord) are a paired bundle of nerve fibers that run from the base of the skull to the coccyx. They are a major component of the sympathetic nervous system. Structure The sympathetic trunk lies j ...

passes downward in front of them, and the

splanchnic nerves The splanchnic nerves are paired visceral nerves (nerves that contribute to the innervation of the internal organs), carrying fibers of the autonomic nervous system ( visceral efferent fibers) as well as sensory fibers from the organs ( visceral a ...

also descend in front by the lower arteries. Each artery then divides into an anterior and a posterior ramus. A given posterior intercostal artery travels along the bottom of the rib with its corresponding

posterior intercostal vein The posterior intercostal veins are veins that drain the intercostal spaces posteriorly. They run with their corresponding posterior intercostal artery on the underside of the rib, the vein superior to the artery. Each vein also gives off a dors ...

, as well as the

intercostal nerve 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 diff ...

of the given space. The vein is superior to the artery, and the intercostal nerve is inferior to it. Commonly, the mnemonic, "Van," is used to recall the order of the vein, artery and nerve, from superior to inferior.

References

External links

* - " Thoracic wall: 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

See also

References

External links