The key difference between superior and inferior vena cava is that superior vena cava brings deoxygenated blood into the right atrium of the heart from the upper half of the body while inferior vena brings deoxygenated blood into the right atrium of the heart from the lower part of the body.
Superior vena cava and inferior vena cava, collectively known as the ‘venae cavae, are the two largest veins that carry deoxygenated blood from lower and upper halves of the body into the heart. Both deliver blood to the right atrium of the heart. Both these veins do not have valves at the inlet of the right atrium. Furthermore, venae cavae and aorta form the systemic circuit, which maintains the blood circulation of the head, extremities and abdomen. However, this article mainly focuses on the difference between superior and inferior vena cava.
CONTENTS
1. Overview and Key Difference
2. What is Superior Vena Cava
3. What is Inferior Vena Cava
4. Similarities Between Superior and Inferior Vena Cava
5. Side by Side Comparison – Superior vs Inferior Vena Cava in Tabular Form
6. Summary
What is Superior Vena Cava?
Superior vena cava is a large vein which brings deoxygenated blood into the right atrium of the heart from the upper half of the body, including neck, head and upper limbs. It begins above the heart. Moreover, superior vena cava is formed from the convergence of the left and right brachiocephalic veins, which carry blood from the upper limbs, head, and neck, and azygous vein (which carry blood from the thoracic area).
What is Inferior Vena Cava?
Inferior vena cava is the largest vein in the body, which carries deoxygenated blood from the lower half of the body into the right atrium of the heart. It is situated posterior to the abdominal cavity and runs to the heart next to the abdominal aorta.
Figure 02: Superior and Inferior Vena Cava
The convergence of right and left common iliac veins form the inferior vena cava. Moreover, this vein is not located centrally; thus, there are some asymmetric drainage patterns.
What are the Similarities Between Superior and Inferior Vena Cava?
- Superior and inferior vena cava are two veins.
- They bring deoxygenated blood to the right atrium of the heart.
- Also, both have a wide lumen.
- And, they have thin walls.
- In addition, there are valves inside both veins to prevent the backflow of blood.
What is the Difference Between Superior and Inferior Vena Cava?
Superior vena cava, which brings deoxygenated blood from the upper part of the body to right atrium, is the second largest vein in the body, while inferior vena cava, which brings deoxygenated blood from the lower part of the body to the right atrium, is the largest vein in the body. So, this is the key difference between superior and inferior vena cava. Furthermore, inferior vena cava is longer than superior vena cava. Hence, this is also a difference between superior and inferior vena cava.
Moreover, a further difference between superior and inferior vena cava is that superior vena cava brings deoxygenated blood from the upper limbs, head, and neck while inferior vena cava brings deoxygenated blood from lower limbs, gonads, kidneys and liver.
The below infographic summarizes the difference between superior and inferior vena cava comparatively.
Summary – Superior vs Inferior Vena Cava
In brief, superior vena cava and inferior vena cava are two veins that bring deoxygenated blood to the heart. In fact, they bring blood to the right upper chamber of the heart, which is the right atrium. However, the key difference between superior and inferior vena cava is that the superior vena cava collects deoxygenated blood from the upper half of the body while inferior vena cava collects deoxygenated blood from the lower part of the body.
Reference:
1. “Vena Cava.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 10 Oct. 2012, Available here.
Image Courtesy:
2. “Gray505” By Henry Vandyke Carter – Henry Gray (1918) Anatomy of the Human Body (See “Book” section below)Bartleby.com: Gray’s Anatomy, Plate 505 (Public Domain) via Commons Wikimedia