inferior vena cava

Examples of inferior vena cava in the following topics:

• Veins of the Thorax

  • Two venae cavae return deoxygenated blood from the systemic circulation to the right atrium of the heart.
  • The superior vena cava, formed from the left and right brachiocephalic veins, returns deoxygenated blood from the upper half of the body and carries blood from the upper limbs, head, and neck via the thyroid and jugular veins.
  • The inferior vena cava returns blood from the abdomen and lower limbs to the right atrium of the heart.
  • The renal veins from the kidney and hepatic veins of the liver drain directly into the inferior vena cava.
  • Additionally, the superior and inferior phrenic veins drain the diaphragm and usually open into the internal mammary vein and inferior vena cava, respectively.

• Great Vessels of the Heart

  • The superior and inferior vena cava are collectively called the venae cavae.
  • The superior vena cava begins above the heart.
  • The inferior vena cava is the largest vein in the body and carries deoxygenated blood from the lower half of the body into the heart.
  • The left and right common iliac veins converge to form the inferior vena cava at its lowest point.
  • The inferior vena cava begins posterior to the abdominal cavity and travels to the heart next to the abdominal aorta.

• Principal Veins

  • The venae cavae are the veins with the largest diameter.
  • 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.
  • The inferior vena cava is formed from the common iliac veins that serve the legs and abdomen.
  • The renal and hepatic veins from the kidneys and liver respectively also feed into the inferior vena cava.

• Supply of Blood and Nerves to the Kidneys

  • Due to the position of the aorta, the inferior vena cava, and the kidneys in the body, the right renal artery is normally longer than the left renal artery.
  • Renal blood supply starts with the branching of the aorta into the renal arteries (which are each named based on the region of the kidney they pass through) and ends with the exiting of the renal veins to join the inferior vena cava.
  • The renal veins are the veins that drain the kidneys and connect them to the inferior vena cava.

• Abdominal Aorta

  • The abdominal aorta runs parallel to the inferior vena cava, located just to the right of the abdominal aorta.

• Veins of the Abdomen and Pelvis

  • The left and right common iliac veins come together in the abdomen at the level of the fifth lumbar vertebra, forming the abdominal vena cava.
  • It anastomoses with the inferior epigastric vein at the level of the umbilicus and drains the anterior part of the abdominal wall and some of the diaphragm.
  • The inferior epigastric vein refers to the vein that drains into the external iliac vein and arises from the superior epigastric vein.
  • The deep circumflex iliac vein is formed by the union of the venae comitantes of the deep iliac circumflex artery, and joins the external iliac vein about 2 cm above the inguinal ligament.
  • The veins of the abdomen and lower limb include the inferior vena cava, the common iliac veins, the external iliac veins, and their tributaries.

• Hepatic Portal Circulation

  • Following processing, blood collects in a central vein that drains into the hepatic vein and finally the inferior vena cava.

• Directional Terms

  • Superior and inferior (cranial and caudal) are used when referring to parts of the body which are toward an end of the body.
  • Superior structures are toward the head (cranial) while inferior (caudal) structures are toward the feet.
  • Examples include the superior and inferior vena cava, which carry deoxygenated blood away from the head (superior) and from the lower body (inferior) to the heart.
  • Anterior and posterior are sometimes used in place of superior and inferior, respectively.

• Autonomic Plexuses

  • The autonomic plexuses include the cardiac plexus, the pulmonary plexus, the esophageal plexus, and abdominal aortic plexus, and the superior and inferior hypogastric plexuses.
  • It is situated on the sides and front of the aorta, between the origins of the superior and inferior mesenteric arteries.
  • From this plexus arise parts of the spermatic, the inferior mesenteric, and the hypogastric plexuses; it also distributes filaments to the inferior vena cava.
  • The inferior hypogastric plexus (pelvic plexus in some texts) is a plexus of nerves that supplies the viscera of the pelvic cavity.
  • The inferior hypogastric plexus is a paired structure, with each situated on the side of the rectum in the male, and at the sides of the rectum and vagina in the female.

• Systemic and Pulmonary Circulation

  • Oxygen-depleted blood from the body leaves the systemic circulation when it enters the right atrium through the superior and inferior venae cavae.
  • The deoxygenated blood continues through the capillaries which merge into venules, then veins, and finally the venae cavae, which drain into the right atrium of the heart.