Ulnar vein

A blood vessel that plays a crucial role in returning deoxygenated blood from the forearm to the heart.

The ulnar vein is a paired vessel that accompanies the ulnar artery on the inner side of the forearm. It is responsible for draining blood from the medial aspect of the forearm and part of the hand, before merging with the radial vein to form the brachial vein. The ulnar vein is crucial for the effective circulation of venous blood back to the heart.

Terminologia Anatomica

vena ulnaris

System

Circulatory system

Function

The primary function of the ulnar vein is to collect deoxygenated blood from the hand and forearm, including the intrinsic muscles of the hand and the skin on the inner forearm. Once the blood is collected, it is channeled towards the brachial vein, which ultimately transports it to the superior vena cava and into the right atrium of the heart. This process is essential for maintaining proper blood circulation and ensuring that carbon dioxide and other metabolic waste products are efficiently removed from the tissues. The ulnar vein, alongside its paired artery, also helps to regulate the temperature of blood flowing from the body to the heart, contributing to overall homeostasis. Additionally, the valves within the ulnar vein prevent backflow of blood, ensuring a steady flow towards the heart, even against gravity.

Location

The ulnar vein is located on the medial side of the forearm, running parallel to the ulnar artery. It begins approximately at the level of the wrist, where it receives tributaries from the hand, including digital veins. As it ascends towards the elbow, it aligns closely with the course of the ulnar artery, eventually joining with the radial vein at the cubital fossa to form the brachial vein. Its anatomical position remains important because it lies in the superficial compartment of the forearm between layers of muscle and fascia, making it accessible for medical procedures such as venipuncture.

Did You Know?

The ulnar vein can also be a site for blood sampling or intravenous therapy due to its accessibility.
In some individuals, additional veins accompany the ulnar vein, showcasing variations in venous anatomy.
The ulnar vein is part of a larger network of superficial and deep veins, enabling complex blood drainage systems in the arm.
Unlike arteries, which have thick muscular walls to withstand high pressure, veins like the ulnar have thinner walls and valves to help maintain blood flow.