Thoracic Aorta

Examples of Thoracic Aorta in the following topics:

• Thoracic Aorta

  • The thoracic aorta is the section of the aorta that travels through the thoracic cavity to carry blood to the head, neck, thorax and arms.
  • 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.
  • The posterior intercostal arteries are branches that originate throughout the length of the posterior aspect of the thoracic aorta.
  • 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.

• 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 lies slightly to the left of the midline of the body.
  • The aorta, highlighted in red, includes the abdominal aorta which begins at the diaphragm and ends as it branches into the common iliac arteries.

• Great Vessels of the Heart

  • The subclavian veins are significant because the thoracic lymphatic duct drains lymph fluid into the subclavian veins, making the superior vena cava a site of lymph fluid recirculation into the plasma.
  • The ascending aorta lies between the heart and the arch of aorta.
  • It is subdivided into the thoracic and abdominal aorta.
  • The thoracic aorta is  the part of the descending aorta above the diaphragm.
  • 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.

• 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 an elastic artery, meaning it is able to distend.
  • When the left ventricle contracts to force blood into the aorta, the aorta expands.
  • 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.
  • It is divided into two portions, the thoracic and abdominal, in correspondence with the two great cavities of the trunk in which it sits.

• 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.

• Anatomy of the Heart

  • The heart is located in the thoracic cavity between the lungs and protected by the rib cage.
  • The left side of the heart receives oxygenated blood from the pulmonary vein and pumps it into the aorta, while the right side of the heart receives deoxygenated blood from the vena cava and pumps it into the pulmonary vein.
  • The pulmonary vein and aorta also have valves connecting them to their respective ventricle.
  • The heart is enclosed in a double-walled protective membrane called the pericardium, which is a mesothelium tissue of the thoracic cavity.

• Autonomic Plexuses

  • The superficial part of the cardiac plexus lies beneath the arch of the aorta, in front of the right pulmonary artery.
  • The esophageal plexus and the cardiac plexus contain the same types of fibers and are both considered thoracic autonomic plexus(es).
  • It is situated on the sides and front of the aorta, between the origins of the superior and inferior mesenteric arteries.
  • The superior hypogastric plexus (in older texts, hypogastric plexus or presacral nerve) is a plexus of nerves situated on the vertebral bodies below the bifurcation of the abdominal aorta.

• Principal Veins

  • Both enter the right atrium of the heart with the superior vena cava carrying blood from the arms, head, and thoracic cavity and the inferior vena cava carrying blood from the legs and abdomen.
  • The inferior vena cava runs parallel to the abdominal aorta.

• 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.