The chest is the major hub for circulation. Not only is it where the heart lies, but it also houses major critical organs that require extensive amounts of blood flow to operate.

As the heart pumps inside the center of the chest, oxygenated blood circulates to organs and other tissues starting with the aorta, the largest artery in the body, and arteries that branch from it. Deoxygenated blood returns to the heart through veins.

Oxygen-rich blood returning from the lungs enters the right side of the heart and travels up the ascending aorta and into the aortic arch. From there, some of it continues up through several arteries to the head and arms. Those arteries are:

• Subclavian arteries: These two run on the right and left side of the shoulders under the clavicle. These supply blood to the arms.
• Carotid arteries: These rise up through the neck on the right and left side. They supply blood to the head.

When the tissues all over the body, especially the brain, organs, and muscles, have used the oxygen, the blood returns to the heart through veins, such as the jugular veins in the neck and the axillary veins in the arms.

Both the arteries and veins in this area have a wide, yet short sections that branch off to other vessels, and both affect blood flow to the right arm and the right side of the head. These are known as the brachiocephalic artery and brachiocephalic vein.

Although the head, brain, and arms are important parts, they don’t get all of the blood flow. Blood also flows through the aortic arch and into the thoracic aorta. Together, this aorta and the abdominal aorta make up the descending aorta. Vessels from the descending aorta supply blood to the chest wall, esophagus, and bronchi in the lungs.

The same blood vessel has different names in different sections, but it is essentially one large artery that branches to serve the entire lower half of the body. Injury to this vessel — known as traumatic aortic rupture — is caused by high-speed impacts such as automobile accidents or falls. It is often fatal.

Below the thoracic artery are the intercostal arteries, which supply blood to the ribs, and the celiac artery. The celiac trunk branches to feed blood to the stomach, kidneys, liver, and other organs. 

Next, the abdominal aorta, which is the largest section of the aorta and spans the entire distance of the abdominal cavity, delivers blood to several areas on the way to the legs, where it branches via the iliac arteries.