The Vascular System
The arteries deliver the oxygen-rich blood from the left side of the heart to the rest of the body. They maintain blood pressure and are elastic in nature. Unlike the veins, the arteries do not have valves. The largest artery is the Aorta.
The veins bring the deoxygenated blood from all the body tissues to the right side of the heart. The leg muscles, especially the calves, act as pumps for the blood in the veins against gravity. That’s why the calf muscles are called the “second heart.” Unlike the arteries, the veins have valves to make sure the blood is going upwards and not leaking backward towards the legs.
They do not have enough pressure to push the blood against gravity so they have valves to help the blood from flowing backward. The largest veins are the Superior and Inferior Vena Cavas.
The capillaries are the smallest vessels in the body that connect the arteries and the veins. They distribute the oxygen and nutrients from blood in the arteries to all the cells of the body and collect carbon dioxide and waste productions from all the body cells and bring it back to the veins.
There are two main categories of circulation in the body pulmonary (lungs) and systemic (whole-body)
Pulmonary Circulation – is how the deoxygenated (low oxygen) blood from the right heart goes to the lungs to get oxygenated (loaded with oxygen) and returns to the left heart to be pumped out to the rest of the body.
Systemic Circulation – begins when the oxygen-rich blood from the left heart is pumped out to the rest of the body. The blood travels from the left heart → Aorta → arteries → arterioles → capillaries → venules → veins → Inferior Vena Cava → back to the left heart
The arteries of your extremities/ limbs (hands, arms, feet, and legs) are known as peripheral arteries.
There are two carotid arteries in your neck: right and left. They are the major blood vessels in the that deliver blood from your heart to the face, neck, and brain.
Renal Arteries – supply oxygenated blood to the kidneys
Renal Veins – remove the deoxygenated blood from the kidneys
Ureter – a tube that collects urine from the kidney and delivers it to the bladder