Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
Gill circulation is the process by which blood flows through the gills of aquatic organisms, facilitating gas exchange. Oxygen is absorbed from water while carbon dioxide is expelled.
5 Must Know Facts For Your Next Test
1. Gill circulation occurs in fish and some amphibians as part of their respiratory system.
2. Blood flows through capillaries in the gills where oxygen is picked up and carbon dioxide is released.
3. The counter-current exchange mechanism maximizes oxygen absorption efficiency.
4. Gill arches support gill filaments which are the primary sites for gas exchange.
5. Hemoglobin in the blood binds to oxygen molecules absorbed through the gill membranes.
Review Questions
Related terms
Counter-current Exchange: A mechanism where fluids flow in opposite directions, maximizing transfer rates of substances like oxygen and carbon dioxide between blood and water.
Gill Filaments: Thin projections on gill arches that increase surface area for gas exchange in aquatic organisms.