Pulmonary arteries

Vessels that carry deoxygenated blood from the heart to the lungs for oxygenation.

The pulmonary arteries are a pair of major blood vessels that arise from the right ventricle of the heart and transport deoxygenated blood to the lungs. In the lungs, carbon dioxide is exchanged for oxygen, leading to the oxygenation of blood. Unlike most arteries, which carry oxygen-rich blood, pulmonary arteries play a crucial role in pulmonary circulation.

Terminologia Anatomica

arteriae pulmonales

System

Circulatory system

Function

The primary function of the pulmonary arteries is to facilitate the transport of deoxygenated blood from the heart to the lungs. Once the right ventricle contracts, it sends blood through the pulmonary valve into the pulmonary arteries. These vessels then branch off and extend into the lungs, supplying blood to the surrounding alveoli (air sacs) where gas exchange occurs. Here, carbon dioxide is expelled from the blood and oxygen is absorbed. This oxygen-rich blood is then returned to the left side of the heart via the pulmonary veins, ready to be distributed throughout the body. The efficient functioning of the pulmonary arteries is essential for maintaining the body's oxygen supply and ensuring that carbon dioxide is removed effectively.

Location

The pulmonary arteries originate directly from the right ventricle of the heart. They bifurcate into the left and right pulmonary arteries, with each artery directing blood to its respective lung. The right pulmonary artery runs horizontally towards the right lung while the left pulmonary artery ascends and curves slightly to the left to reach the left lung. They traverse the mediastinum, the central compartment of the thoracic cavity, and lie posterior to the ascending aorta and the superior vena cava. Due to their strategic position, these arteries are critical for efficient pulmonary circulation, connecting the right side of the heart with the lungs where the critical exchange of gases occurs.

Did You Know?

The pulmonary arteries are the only arteries in the body that carry deoxygenated blood.
They are approximately 5 cm long and can expand to accommodate changes in blood volume.
Pulmonary artery pressure is a key indicator of heart health; elevated pressure can indicate pulmonary hypertension.