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

They may arise separately from the front of the aorta

Aorta

The aorta is the largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries...

, immediately above the celiac artery

Celiac artery

The celiac artery, also known as the celiac trunk, is the first major branch of the abdominal aorta. Branching from the aorta anterior to the upper border of L1 vertebra in humans, it is one of three anterior/ midline branches of the abdominal aorta The celiac (or coeliac) artery, also known as...

, 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; they rarely arise as separate vessels from the aorta.

They diverge from one another across the crura of the diaphragm, and then run obliquely upward and lateralward upon its under surface.

• The left phrenic passes behind the esophagus
  Esophagus
  The esophagus is an organ in vertebrates which consists of a muscular tube through which food passes from the pharynx to the stomach. During swallowing, food passes from the mouth through the pharynx into the esophagus and travels via peristalsis to the stomach...
  
  , and runs forward on the left side of the esophageal hiatus
  Esophageal hiatus
  In human anatomy, the esophageal hiatus is a hole in the diaphragm through which the esophagus passes. It is located in the right crus of the diaphragm.It is located approximately at level of the tenth thoracic vertebra ....
  
  .

• The right phrenic passes behind the inferior vena cava
  Inferior vena cava
  The inferior vena cava , also known as the posterior vena cava, is the large vein that carries de-oxygenated blood from the lower half of the body into the right atrium of the heart....
  
  , and along the right side of the foramen which transmits that vein
  Caval opening
  The caval opening is a hiatus in the diaphragm of humans through which passes the inferior vena cava, the wall of which is adherent to the margins of the opening, and some branches of the right phrenic nerve....
  
  .

Near the back part of the central tendon

Central tendon

The central tendon of the diaphragm is a thin but strong aponeurosis situated slightly anterior to the vault formed by the muscle, resulting in longer posterior muscle fibers....

 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 and pericardiacophrenic arteries.

• The lateral branch passes toward the side of the thorax, and anastomoses with the lower intercostal arteries, and with the musculophrenic. The lateral branch of the right phrenic gives off a few vessels to the inferior vena cava
  Inferior vena cava
  The inferior vena cava , also known as the posterior vena cava, is the large vein that carries de-oxygenated blood from the lower half of the body into the right atrium of the heart....
  
  ; and the left one, some branches to the esophagus
  Esophagus
  The esophagus is an organ in vertebrates which consists of a muscular tube through which food passes from the pharynx to the stomach. During swallowing, food passes from the mouth through the pharynx into the esophagus and travels via peristalsis to the stomach...
  
  .

Each vessel gives off superior suprarenal branches to the suprarenal gland of its own side. The spleen

Spleen

The spleen is an organ found in virtually all vertebrate animals with important roles in regard to red blood cells and the immune system. In humans, it is located in the left upper quadrant of the abdomen. It removes old red blood cells and holds a reserve of blood in case of hemorrhagic shock...

 and the liver

Liver

The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...

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

External links

- "Posterior Abdominal Wall: Branches of the Abdominal Aorta" (#23)