Umbilical Vein, all other vessels have varying degrees of oxygenated and deoxygenated blood.
The umbilical vein carries oxygen-rich blood from the placenta to the fetus, making it the fetal blood vessel with the highest oxygen concentration.
The aorta just as it comes out of your left ventricle.
In the umbilical cord you have one vein and two arteries. This vein goes to the liver of foetus. This blood vessel contains most oxygen and food in case of foetus. After birth this vessel gets obliterated to form the falciform ligament.
The pulmonary arteries contain the least oxygen as they carry deoxygenated blood from the heart to the lungs for oxygenation.
The blood in the pulmonary veins contains the highest concentration of oxygen since it has just been oxygenated in the lungs before returning to the heart to be pumped to the rest of the body.
The pulmonary artery contains the least amount of oxygen, as it carries deoxygenated blood from the heart to the lungs to be oxygenated.
The pulmonary vein carries blood rich in oxygen from the lungs to the heart. This oxygenated blood is then pumped to the rest of the body through the aorta.
Pulmonary arterial system has high pressure but low oxygen concentration.
Left atrium.
the capillaries are the most common blood vessel in the human body.
in the veins
Aorta has highest pressure. Pressure gradually decreases as blood moves towards heart.