The inferior phrenic arteries are two small vessels which supply the diaphragm. They present much variety in their origin.

Structure

Origin

The inferior phrenic arteries usually arise between T12 and L2

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 ...

. They may arise separately from the front of the

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 ...

, immediately above the

celiac artery The celiac () artery (also spelled ''coeliac''), also known as the celiac trunk or truncus coeliacus, is the first major branch of the abdominal aorta. It is about 1.25 cm in length. Branching from the aorta at thoracic vertebra 12 (T12) in ...

, or by a common trunk, which may spring either from the aorta or from the celiac artery. Sometimes one is derived from the aorta, and the other from one of the

renal arteries The renal arteries are paired arteries that supply the kidneys with blood. Each is directed across the crus of the diaphragm, so as to form nearly a right angle. The renal arteries carry a large portion of total blood flow to the kidneys. Up to a ...

; they rarely arise as separate vessels from the aorta.

Branches

They diverge from one another across the

crura of the diaphragm The crus of diaphragm (pl. crura), refers to one of two tendon, tendinous structures that extends below the thoracic diaphragm, diaphragm to the vertebral column. There is a right crus and a left crus, which together form a tether for muscular cont ...

, and then run obliquely upward and lateralward upon its under surface. * The ''left phrenic'' passes 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 the ...

, and runs forward on the left side of the

esophageal hiatus In human anatomy, the esophageal hiatus is an opening in the diaphragm through which the esophagus and the vagus nerve pass. Structure It is located in the right crus, one of the two tendinous structures that connect the diaphragm to the spine ...

. * The ''right phrenic'' passes behind the

inferior vena cava The inferior vena cava is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart. It is formed by the joining of the right and the left common iliac veins, usually at the level of the ...

, and along the right side of the foramen which transmits that vein. Near the back part of the central tendon each vessel divides into a medial and a lateral branch. * The ''medial branch'' curves forward, and anastomoses with its fellow of the opposite side, and with the

musculophrenic The intercostal arteries are a group of arteries that supply the area between the ribs ("costae"), called the intercostal space. The highest intercostal artery (supreme intercostal artery or superior intercostal artery) is an artery in the human ...

and

pericardiacophrenic The pericardiacophrenic artery is a long slender branch of the internal thoracic artery. It anastomoses with the musculophrenic and superior phrenic arteries. Location The pericardiacophrenic artery branches from the internal thoracic artery. ...

arteries. * The ''lateral branch'' passes toward the side of the thorax, and anastomoses with the

lower intercostal The intercostal arteries are a group of arteries that supply the area between the ribs ("costae"), called the intercostal space. The highest intercostal artery (supreme intercostal artery or superior intercostal artery) is an artery in the human ...

arteries, and with the

. The lateral branch of the right phrenic gives off a few vessels to the

; and the left one, some branches to the

Function

The inferior phrenic arteries supply the diaphragm. Each of the smaller vessels give off superior suprarenal branches to the suprarenal gland of its own side. The

spleen The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes .

and the

liver The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for ...

also receive a few twigs from the left and right vessels respectively.

References

External links

* - "Posterior Abdominal Wall: Branches of the Abdominal Aorta" * (#23) {{Authority control Arteries of the abdomen