Venae cavae

Major veins in the human body

The vena cavae are two large veins (the superior vena cava and the inferior vena cava) that carry deoxygenated blood from the body back to the heart. They are essential components of the circulatory system.

Structure

Superior vena cava

The superior vena cava is a large, short vein that receives venous return from the upper half of the body, above the diaphragm. It is formed by the left and right brachiocephalic veins and drains into the right atrium of the heart. The superior vena cava is located in the thoracic cavity and is approximately 7 cm long.

Inferior vena cava

The inferior vena cava is the largest vein in the human body. It is formed by the joining of the left and right common iliac veins and carries blood from the lower half of the body. The inferior vena cava ascends through the abdomen and the thorax to enter the right atrium of the heart. It is located to the right of the aorta and is approximately 22 cm long.

Function

The primary function of the vena cavae is to return deoxygenated blood to the heart. The superior vena cava collects blood from the head, neck, upper limbs, and upper torso, while the inferior vena cava collects blood from the lower limbs, pelvis, and abdomen. This blood is then pumped into the right atrium, from where it is sent to the right ventricle and then to the lungs for oxygenation.

Clinical significance

The vena cavae are critical for maintaining proper blood circulation. Conditions such as superior vena cava syndrome can occur when the superior vena cava is obstructed, leading to swelling and other symptoms. The inferior vena cava can be affected by conditions such as deep vein thrombosis, which can lead to pulmonary embolism if a clot travels to the lungs.

Related pages

• Circulatory system
• Heart
• Vein
• Superior vena cava
• Inferior vena cava

References

• Gray, Henry. Gray's Anatomy: The Anatomical Basis of Clinical Practice. 41st edition. Elsevier.
• Moore, Keith L., et al. Clinically Oriented Anatomy. 7th edition. Lippincott Williams & Wilkins.

Diagram of the human heart showing the vena cavae