Lungs
In fishes, oxygen is carried to the rest of the body by their circulatory system. Deoxygenated blood is pumped from the heart to the gills where it picks up oxygen, and then is circulated to the rest of the body.
Blood has less oxygen in it when it travels through the body's tissues and organs, giving up oxygen to cells for energy production. This deoxygenated blood then returns to the lungs, where it picks up more oxygen to be transported to the rest of the body.
After picking up oxygen in the lungs, blood travels to the heart's left side and is pumped out to the rest of the body through the aorta. From there, the oxygenated blood circulates through the body's arteries, delivering oxygen and nutrients to tissues and organs.
Iron and hemoglobin ( a substance found in your red blood cells) combine with oxygen and it turns the blood color from a dark color, to a healthy bright color, also iron picks up oxygen, and carries it through the rest of your body.
The aorta is the largest artery in the human body.
The left side of the heart is rich in oxygen because it receives blood from the lungs, where it picks up oxygen through gas exchange. This oxygen-rich blood is then pumped out to the rest of the body to supply tissues with the oxygen they need for cellular function.
Oxygen-poor blood leaves the heart via the pulmonary artery and is transported to the lungs for oxygenation. Once it picks up oxygen in the lungs, it returns to the heart through the pulmonary vein to be pumped out to the rest of the body.
deoxygenated
Blood is pumped to the lungs first so that carbon dioxide can be released and oxygen can be picked up. This process allows the blood to be oxygenated before it is pumped to the rest of the body to deliver oxygen and nutrients to tissues and organs.
The heart takes in oxygen from the environment and delivers it to cells.
Arteries flowing into every organ contain oxygen. Oxygen is life for humans. Our brain, lungs, heart, etc. need it to survive. Oxygen is carried by arterial blood because we inhale it as we breathe. The lungs then distribute the oxygen to the rest of the body via arteries.
The lungs have tiny little finger-like things at the bottom of the inner-lung. They pick up oxygen and send it to the heart. Then blood picks up the oxygen and the heart pumps it to the rest of the body. That's when you have a satisfied breath.