Zusammenfassung der Ressource
Capillaries
- Arterioles feed into networks of capillaries
- The capillaries link the arterioles to the venules
- BLOOD ENTERING THE CAPILLARIES IS OXYGENATED
- BLOOD LEAVING CARRIES LESS OXYGEN AND MORE CARBON DIOXIDE
- Capillaries are very small vessels that spread throughout the tissues of the body
- They branch between cells, no cell is far away from a capillary
- Substances can diffuse between cells and the blood quickly
- Because the diameter of the capillaries is small blood travels slowly allowing more time for diffusion
- STRUCTURE
- Thin walls with no elastic fibers or muscle
- Helps them fit between cells
- Walls consist one one thin cell
- Diffusion occurs at a faster rate
- Oxygen and other molecules can quickly diffuse out
- Carbon dioxide and waste molecules can quickly diffuse in