Blood loses oxygen in the capillaries, which are tiny blood vessels located throughout the body.
The Journey of Oxygen in the Blood
Here's a simplified breakdown of how oxygen is transported and delivered:
- Oxygen Uptake: Blood circulation starts in the heart, which pumps blood to the lungs. Red blood cells in the blood pick up oxygen in the lungs.
- Arterial Transport: Oxygen-rich blood travels away from the heart and lungs through arteries.
- Capillary Delivery: The oxygen-rich blood reaches tiny blood vessels called capillaries. This is where red blood cells drop off oxygen to the cells.
Why Capillaries?
- Thin Walls: Capillaries have very thin walls that allow oxygen to easily pass out of the blood and into the surrounding tissues.
- Extensive Network: They are numerous and spread throughout the body, ensuring that all cells have access to oxygen.
Table Summary
| Location | Function | Oxygen Levels |
|---|---|---|
| Lungs | Red blood cells pick up oxygen | High |
| Arteries | Transport oxygen-rich blood | High |
| Capillaries | Red blood cells drop off oxygen to cells | Decreasing |
Conclusion
The capillaries are the crucial point where oxygen leaves the blood and enters the body's tissues.
