Fish

• What is the primary function of gills in fish?

  Gas exchange
• How do lamellae contribute to gas exchange in fish?

  They provide a large surface area for exchange
• What is the composition of lamellae that aids in gas exchange?

  They are made of thin epithelial tissue
• Why is the thinness of epithelial tissue in lamellae important?

  It allows for a short distance between blood and water
• What are the two types of flow involved in fish ventilation?

  Continuous flow and countercurrent flow
• How does countercurrent flow work in fish gills?

  Blood and water flow in opposite directions
• What advantage does countercurrent flow provide in fish gills?

  It maintains a concentration gradient over the whole length of the gill
• How does countercurrent flow affect diffusion in fish gills?

  Diffusion can occur over the whole gill
• What is the result of more oxygen entering the blood in fish?

  More oxygen enters blood and more CO₂ leaves