Anatomy of the Vessels

We will restrict our study mainly to the large arteries and veins in the chest.  We will also learn the arteries in the abdomen and groin in order to understand the path used for transcatheter aortic valve replacement.  The material to study includes videos from Acland's Video Atlas of Anatomy, and pictures of a heart model from the Health Sciences Library.

Arteries

The large arteries that carry blood away from the heart emanate from the base of the heart.  The pulmonary trunk is slightly anterior of the aorta and pointing to the left.  The aorta heads superiorly (ascending aorta), tilting towards the right, before arching to the left (aortic arch).  Three large arteries that supply the arms and head are attached to the aortic arch:  the brachiocephalic artery, the left common carotid artery, and the left subclavian artery.   

Three large arteries branch from the aortic arch. On the right, the brachiocephalic artery heads superiorly, then branches into the right subclavian artery and the right common carotid artery. The subclavian artery is so named because it is deep to the clavicle. This artery supplies blood flow to the arms. The common carotid artery (which supplies blood to the head) travels superiorly in the neck, eventually branching to give rise to the external and internal carotid arteries. Where it branches, there is a swelling called the carotid sinus. This is a location for the carotid baroreceptors, sensory neurons that monitor the blood pressure.

There is no brachiocephalic artery on the left side. Instead, the left common carotid artery and the left subclavian artery directly branch off of the aortic arch. Both vessels head superiorly away from the arch, but the subclavian artery turns laterally just below the clavicle.

After the aortic arch, the aorta descends through the chest cavity (descending thoracic aorta), then enters the abdomen (abdominal aorta), bringing blood to arteries that supply the abdominal organs and the legs.  At the level of the 4th lumbar vertebra, the aorta divides, forming the two common iliac arteries.  The common iliac artery divides to give rise to the internal iliac artery (traveling medially into the pelvic cavity) and the external iliac artery, which supplies blood to the legs.  The artery passes under the inguinal ligament and exits the abdominal cavity to lie in a position at the top of the thigh.  After, it exits the abdomen, the artery is called the femoral artery.  The femoral artery is a convenient access point for percutaneous (through the skin) cardiac valve surgery.

Veins

The superior vena cava and the inferior vena cava are the largest veins that deliver blood directly to the right atrium. The inferior vena cava is mainly located in the abdominal cavity.  We will focus on the veins that bring blood to the superior vena cava. The vein that drains blood from the arms is called the subclavian vein, which runs parallel to the subclavian artery. The large vein that drains blood from the head is the internal jugular vein. This vein runs adjacent to the common carotid artery in the neck.  The subclavian and internal jugular veins join to form the brachiocephalic veins.  Because the superior vena cava lies on the right side of the body, the right brachiocephalic vein is short and verticallly oriented and the left brachiocephalic vein is longer and obliquely oriented.

Heart Model:  Coronary Circulation

The heart tissue has its own circulation that supplies oxygen and nutrients: this is called the coronary circulation. The term "coronary" derives from the fact that the large vessels of the coronary circulation encircle the heart like a crown. Emanating from the front of the aorta are two coronary arteries.  These arteries may be narrowed by atherosclerosis, reducing blood flow and causing pain (angina pectoralis).  A myocardial infarction (heart attack) is when a coronary artery is blocked and heart tissue dies.  As the model shows, the coronary veins parallel the coronary arteries.  The coronary veins drain into a large vessel located on the posterior side of the heart in the groove between the atria and ventricles called the coronary sinus.  The coronary sinus connects to right atrium.

Use the pictures of the heart model to identify the major vessels of the coronary circulation, as well as other large vessels of the chest.