The Aorta

   The aorta is the largest artery in the body. The function of the aorta is to send oxygenated blood to the body. That means all of the blood in the systemic circuit of the circulatory system has to go through the aorta. ​

   The aorta has different regions. The first segment of the aorta ascends upward and is appropriately called the ascending aorta. The next segment makes a U-turn and forms and arch. This portion is call the aortic arch. The aortic arch has 3 vessels that project off of it superior. These 3 vessels collectively, function to bring oxygenated blood to the upper portions of the body.  

---

   After the aortic arch, the aorta turns inferiorly and descends as the descending aorta. The portion of the descending aorta hat gies through the thoracic cavity ids called the thoracic aorta. Once the the thoracic aorta travels through the diaphragm, it leave the thoracic cavity and enters into the abdominal cavity. This portion of the descending aorta is called the abdominal aorta.

The Branches of the Aortic Arch

The aortic arch contains 3 branches

1. the brachiocephalic trunk 
2. the left common carotid artery 
3. the left subclavian artery ​

The Brachiocephalic Trunk, Left Common Carotid Artery and Left Subclavian Arteries in the Anatomical Model of the Torso

      The 3 branches of the aortic arch function, collectively, to carry oxygenated blood to the upper regions of the body. The first branch is the brachiocephalic trunk. The brachiocephalic trunk bifurcates (splits into 2) to form the right subclavian artery and the right common carotid artery. The right subclavian artery supplies blood to the right arm and the right common carotid artery will continue to travel superiorly and supply blood to the right side of the head, neck and brain. 

    The second branch is the left common carotid artery and it supplies blood to the left side of the head, neck and brain. The third branch is the left subclavian artery and it supplies blood to the left arm.
 The descending aorta supplies blood to the lower portions of the body.

The Brachiocephalic Trunk, Left Common Carotid Artery and Left Subclavian Arteries in the Anatomical Model of the Heart

The Pulmonary Trunk and Pulmonary Arteries

    Another large artery you see in the heart is colored BLUE because it is carrying deoxygenated blood from the right ventricle to the lungs. This artery is called the pulmonary trunk. The pulmonary trunk branches off to form the right and left pulmonary arteries. The right pulmonary artery carries the blood to the right lung and the left pulmonary artery carries blood to the left lung.

The Brachiocephalic Veins

        The right and left brachiocephalic veins come together to form the superior vena cava. The word "brachio-" means "upper arm" and the word "cephalic" means "head". The right brachiocephalic vein brings deoxygenated blood from the right side of the head and the right arm, to the superior vena cava. The left brachiocephalic vein brings deoxygenated blood from the left side of the head and neck and the left arm, to the superior vena cava

The Pulmonary Veins

        Oxygenated blood coming from the lungs returns to the heart through the right and left pulmonary veins. The veins are colored RED, because these veins carry oxygenated blood. The right pulmonary veins bring oxygenated blood from the right lung to the left atrium of the heart. The left pulmonary veins bring oxygenated blood from the left lung to the left atrium of the heart.

The Superior and Inferior Vena Cava

   The largest veins of the body are the superior and inferior vena cava. The superior vena cava brings deoxygenated blood from the upper body to the right atrium. The inferior vena cava brings deoxygenated blood from the lower body to the right atrium.