Welcome back to our organ system section! Last week we took a brief look at the cardiovascular system so today we are going into detail about the vessels that are a part of this system. Let’s start with our muscular pump, the heart. The great vessels of the heart circulate blood between the heart and lungs and between the heart and the rest of the body. These great vessels include the aorta, pulmonary trunk, pulmonary veins, superior vena cava, and inferior vena cava. These vessels connect the various chambers of the heart depending on their purpose. They send blood in and out of the heart with every heartbeat.
The pulmonary trunk carries deoxygenated blood from the right ventricle into the left and right pulmonary arteries to be sent to the lungs to gain oxygen. The pulmonary veins carry oxygenated blood from the lungs to the right atrium of the heart.
The ascending aorta carries oxygenated blood from the left ventricle to the rest of the body. The ascending aorta becomes the arch of the aorta where three large arteries branch from it. Here we have the brachiocephalic trunk, the left common carotid artery, and the left subclavian artery. These branches supply oxygenated blood to the head, neck, and upper limbs. The descending aorta is in continuation with the arch of the aorta inferiorly. It gives off many branches in the chest cavity and then down to the abdomen where it is called the abdominal aorta. The abdominal aorta ends and separates into the common iliac arteries to supply the pelvic cavity and the lower limbs.
The superior vena cava carries deoxygenated blood from the upper body to the heart’s right atrium.
The inferior vena cava carries deoxygenated blood from the lower body to the heart’s right atrium. Veins and arteries are the major vessels.
Arterioles are very small blood vessels that branch off the artery and carry blood away from the heart to the organs and tissues. Further branching of these arterioles gives us capillaries which are the smallest branches.
The small branches of veins are the venules. These venules collect blood from the capillaries which unite to form the veins of systemic circulation and bring the blood back to the heart for the process to begin again.