| Feature | Artery | Vein | Capillary |
|---|---|---|---|
| Function | Carry blood from heart | Return blood to heart | Exchange materials |
| Pressure | High (120/80 mmHg) | Low (5-10 mmHg) | Very low (20-10 mmHg) |
| Wall thickness | Thick, muscular | Thin | One cell thick |
| Lumen size | Small relative to wall | Large relative to wall | Very small (5-10 ฮผm) |
| Valves | None (except heart exit) | Present throughout | None |
| Elastic fibers | Many | Few | None |
This key facts covers Blood Vessel Adaptations Summary within Blood Components and Vessels for GCSE Biology. Blood composition, red and white blood cells, platelets, plasma, blood vessel structure and function, adaptations for transport It is section 5 of 16 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Blood Components and Vessels
What is the main function of red blood cells?
Explain how red blood cells are adapted for their function of transporting oxygen.
Quick recall flashcards
What is hemoglobin?
A protein in red blood cells containing iron that binds reversibly with oxygen to transport it around the body.
What are platelets?
Small cell fragments with no nucleus that help blood clot by sticking to damaged vessels and releasing clotting factors.