descending aorta

Examples of descending aorta in the following topics:

• The Aorta and Its Branches

  • The aorta is the largest artery in the body and is divided into 3 parts: the ascending aorta, arch of the aorta, and descending aorta.
  • The aorta is divided into three parts: the ascending aorta, where the aorta initially leaves the heart and points superiorly toward the head; the arch of the aorta where the aorta changes direction; and the descending aorta where the aorta points inferiorly toward the feet.
  • The descending aorta is the largest artery in the body; it runs from the heart down the length of the chest and abdomen.
  • Within the abdomen, the descending aorta branches into the two common iliac arteries that provide blood to the pelvis and, eventually, the legs.
  • The aorta has three parts: the ascending, the arch and the descending.

• Abdominal Aorta

  • The abdominal aorta is the largest artery in the abdominal cavity.
  • As part of the descending aorta, it is a direct continuation of the thoracic aorta.
  • The abdominal aorta runs parallel to the inferior vena cava, located just to the right of the abdominal aorta.
  • The abdominal aorta supplies blood to much of the abdominal cavity through numerous branches that become smaller in diameter as it descends.
  • The aorta, highlighted in red, includes the abdominal aorta which begins at the diaphragm and ends as it branches into the common iliac arteries.

• Thoracic Aorta

  • The thoracic aorta forms part of the descending aorta and is continuous with the aortic arch at its origin before becoming the abdominal aorta.
  • At its commencement, the thoracic aorta is situated on the left of the vertebral column; it approaches the median line as it descends, and at its termination lies directly in front of the column.
  • As it descends in the thorax, the aorta gives off several paired branches.
  • In descending order these are the bronchial arteries, the mediastinal arteries, the esophageal arteries, the pericardial arteries, and the superior phrenic artery.
  • The aorta, highlighted in red, includes the thoracic aorta, the section of the aorta which runs from the lower border of the fourth thoracic vertebra to the diaphragm.

• Great Vessels of the Heart

  • The ascending aorta lies between the heart and the arch of aorta.
  • The descending aorta is  the section from the arch of aorta to the point where it divides into the common iliac arteries.
  • The thoracic aorta is  the part of the descending aorta above the diaphragm.
  • The abdominal aorta is the part of the descending aorta below the diaphragm, which divides into the iliac arteries and branches into the renal and suprarenal arteries.
  • The right pulmonary veins pass behind the right atrium and superior vena cava while the left pass in front of the descending thoracic aorta.

• Arch of the Aorta

  • The arch of the aorta follows the ascending aorta and begins at the level of the second sternocostal articulation of the right side.
  • The arch of the aorta, or the transverse aortic arch, is continuous with the upper border of the ascending aorta and begins at the level of the upper border of the second sternocostal articulation of the right side.
  • The arch of the aorta runs at first upward, backward, and to the left in front of the trachea; it is then directed backward on the left side of the trachea and finally passes downward on the left side of the body of the fourth thoracic vertebra.
  • At the lower border, this vertebra becomes continuous with the descending aorta.
  • This diagram shows the arch of the aorta and its branches.

• Ascending Aorta

  • The ascending aorta is the first portion of the aorta; it includes the aortic sinuses, the bulb of the aorta, and the sinotubular junction.
  • The sinotubular junction is the point in the ascending aorta where the aortic sinuses end and the aorta becomes a tubular structure.
  • This dilatation is termed the "bulb of the aorta."
  • The ascending aorta is contained within the pericardium.
  • The aorta has three parts: the ascending, the arch and the descending.

• Adjustments of the Infant at Birth

  • Oxygenated blood now reaches the left atrium and ventricle and, through the descending aorta, reaches the umbilical arteries.
  • The higher blood oxygen content of blood within the aorta stimulates the constriction and ultimately the closure of this fetal circulatory shunt.

• Arteries of the Pelvis and Lower Limbs

  • The abdominal aorta divides into the major arteries of the leg: the femoral, popliteal, tibial, dorsal foot, plantar, and fibular arteries.
  • The pelvic cavity is largely supplied by the paired internal iliac arteries, formed when the common iliac artery divides the internal iliac artery at the vertebral level L5 descends inferiorly into the lesser pelvis.

• Yolk Sac Development

  • Blood is conveyed to the wall of the sac by the primitive aorta.
  • The hypoblast starts proliferating laterally and descending.

• Elastic Arteries

  • The pulmonary arteries, the aorta, and its branches together comprise the body's system of elastic arteries.
  • The aorta is so thick that it requires its own capillary network to supply it with sufficient oxygen and nutrients to function, the vasa vasorum.
  • When the left ventricle contracts to force blood into the aorta, the aorta expands.
  • This stretching generates the potential energy that will help maintain blood pressure during diastole, when the aorta contracts passively.
  • The aorta makes up most of the elastic arteries in the body.