Gills

• ↑
  • Types of repiratory systems

Gills

• External
  • Gills move through water
• Internal
  • Water goes into mouth, and out of gills.
  • Counter Current flow
    • Where water flows across blood vessels through gills and there is constant Diffusion, because new water is always being replaced, and so is the blood.
    • If they were flowing the same way, they would exchange while moving along and reach Equilibrium .