Which blood vessel carries oxygenated blood from the left side of the heart to the main organs of the body?

The blood vessels of the body are functionally divided into two distinctive circuits: pulmonary circuit and systemic circuit. The pump for the pulmonary circuit, which circulates blood through the lungs, is the right ventricle. The left ventricle is the pump for the systemic circuit, which provides the blood supply for the tissue cells of the body.

Pulmonary Circuit

Pulmonary circulation transports oxygen-poor blood from the right ventricle to the lungs, where blood picks up a new blood supply. Then it returns the oxygen-rich blood to the left atrium.

Systemic Circuit

The systemic circulation provides the functional blood supply to all body tissue. It carries oxygen and nutrients to the cells and picks up carbon dioxide and waste products. Systemic circulation carries oxygenated blood from the left ventricle, through the arteries, to the capillaries in the tissues of the body. From the tissue capillaries, the deoxygenated blood returns through a system of veins to the right atrium of the heart.

The coronary arteries are the only vessels that branch from the ascending aorta. The brachiocephalic, left common carotid, and left subclavian arteries branch from the aortic arch. Blood supply for the brain is provided by the internal carotid and vertebral arteries. The subclavian arteries provide the blood supply for the upper extremity. The celiac, superior mesenteric, suprarenal, renal, gonadal, and inferior mesenteric arteries branch from the abdominal aorta to supply the abdominal viscera. Lumbar arteries provide blood for the muscles and spinal cord. Branches of the external iliac artery provide the blood supply for the lower extremity. The internal iliac artery supplies the pelvic viscera.

Major Systemic Arteries

All systemic arteries are branches, either directly or indirectly, from the aorta. The aorta ascends from the left ventricle, curves posteriorly and to the left, then descends through the thorax and abdomen. This geography divides the aorta into three portions: ascending aorta, arotic arch, and descending aorta. The descending aorta is further subdivided into the thoracic arota and abdominal aorta.

Major Systemic Veins

After blood delivers oxygen to the tissues and picks up carbon dioxide, it returns to the heart through a system of veins. The capillaries, where the gaseous exchange occurs, merge into venules and these converge to form larger and larger veins until the blood reaches either the superior vena cava or inferior vena cava, which drain into the right atrium.

Fetal Circulation

Most circulatory pathways in a fetus are like those in the adult but there are some notable differences because the lungs, the gastrointestinal tract, and the kidneys are not functioning before birth. The fetus obtains its oxygen and nutrients from the mother and also depends on maternal circulation to carry away the carbon dioxide and waste products.

The umbilical cord contains two umbilical arteries to carry fetal blood to the placenta and one umbilical vein to carry oxygen-and-nutrient-rich blood from the placenta to the fetus. The ductus venosus allows blood to bypass the immature liver in fetal circulation. The foramen ovale and ductus arteriosus are modifications that permit blood to bypass the lungs in fetal circulation.

BLOOD VESSELS;
AORTA; ARTERY; ARTERIOLE; CAPILLARY; VENULE; VEIN; VENA CAVA

A blood vessel is a tube that carries blood. Oxygen rich blood leaves the left side of the heart and enters the aorta. The aorta branches into arteries, which eventually branch into smaller arterioles. Arterioles carry blood and oxygen into the smallest blood vessels, the capillaries.

Capillaries are so small they can only be seen under a microscope. The walls of the capillaries are permeable to oxygen and carbon dioxide. Oxygen moves from the capillary toward the cells of the tissues and organs. Carbon dioxide moves from the cells and into the capillaries.

Blood leaves the capillary and enters the small venules. These venules become progressively larger vessels called veins. The vena cava are the two largest veins that carry blood into the right upper chamber of the heart (the right atrium). The superior vena cava carries blood from the brain and arms into the top of the right atrium. The inferior vena cava carries blood from the legs and abdominal cavity into the bottom of the right atrium. The vena cava are also called the "central veins". Central venous catheters are inserted with the tip in or close to the superior of inferior vena cava.

Blood is pumped from the right side of the heart into the blood vessels of the lung. When blood enters the small capillaries of the lung (called the pulmonary capillaries), fresh oxygen enters the blood and carbon dioxide is removed. This is called "gas exchange" or "respiration". Because this is the exchange of gases between the atmosphere and the bloodstream, it is also called "external respiration".

When freshly oxygenated blood reaches the capillaries of the tissues, oxygen moves from the blood toward the tissues, and carbon dioxide moves from the tissues toward the blood. This gas exchange that occur between the blood and the cells of the tissues and organs is called "internal respiration".

Blood vessels have a muscle layer that is able to relax or contract. When we need to increase our blood pressure, the muscle layer contracts and makes the blood vessel diameter smaller. This is called "vasoconstriction".

When the muscle layer of a blood vessel relaxes, the blood vessel diameter becomes larger. This is called "vasodilation". Vasodilation lowers the blood pressure.

Drugs that cause the diameter of the blood vessels to change are called vasoactive drugs. Drugs that make blood vessels constrict are used to treat low blood pressure and are called vasocontrictors. Drugs that relax the blood vessels and make them relax are used to treat high blood pressure. They are called vasodilators.

Image 1: Blood Vessels. Arteries (in red) carry oxygen rich blood from the left side of the heart to the tissues and organs. After oxygen leaves the blood and moves into the tissues, the level of oxygen in the blood becomes low. The veins (in blue) carry blood that has a low level of oxygen back to the right side of the heart. Blood from the veins is pumped from the right side of the heart through the blood vessels of the lungs, where new oxygen is picked up. This oxygen rich blood flows from the lungs to the left side of the heart.

What blood vessel carries oxygenated blood to the heart?

Which side of the heart gets the oxygenated blood from the left?

What are the vessels that bring blood to the left side of the heart?