Fish gill..how fish breathe in water

The main function of gills is respiration...In gills, there are many hair like projections called gill filaments..in gill filaments, there are number of lamella, from transfer of gases and water occur..

1. Fish Gills Primary organs of respiration Highly folded structure Located at side of Head High Blood Flow https://www.tes.com/lessons/zKJjkBvGKEGCfQ/creatures-of-the-world http://reptools.rutgers.edu/Fu 1

2. Structure of Gills Gill Filaments : short threads - Network of capillaries -Divided into Lamella(gas exchange site) Gill Arches : support gills Gill Rakers: help in fish feeding Operculum : protect gills http://biologyaqaalevelnotes.blogspot.com/2017/05/exchange-and-transport-systems-gas_48.html https://www.earthlife.net/fish/gills.html 2

3. Adaptation of Gills for Efficient Gas Exchange Large surface area - allow more diffusion of gases Permeable membranes - allow gases to diffuse Thin(Flattened cell) - short diffusion distance Good Vascular supply - Maintain concentration gradient https://www.pathwayz.org/Tree/Plain/FISH +- GAS + EXCHANGE 3

4. Respiratory System of Fish Use their mouth to breathe Exchange oxygen & carbon dioxide Lamella increase surface area 4

5. Countercurrent Exchange & Concurrent Exchange Countercurrent Exchange - Gases flows in opposite direction Maximize oxygen transfer Concurrent Exchange - Gases flow in same direction -No longer diffusion 5

6. Gill Ventilation Fill mouth cavity Fill gill cavity Expel water from gill cavity Reset for new cycle https://branagan12.weebly.com/blog/the-respiratory-system-of-a-bluefin-tuna https://kuensting.org/school/bb/systems/gas_exchange.htm 6

7. Shark Breathing RAM VENTILATION Swimming with Mouth open ttps://giphy.com/gifs/ocean-sharks-Xe60pAwmEygNO BUCCAL PUMPING Contraction of Buccal muscle 7

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