ANATOMY

Detailed explanation-1: -Both the gill filaments and lamellae provide a large surface area for gaseous exchange, increasing the efficiency of diffusion. The lamellae have many blood capillaries and a thin surface layer of cells (or epithelium), this means there is a short diffusion distance.

Detailed explanation-2: -Fish respire through gills, which have evolved to extract aqueous oxygen. Fish gills consist of filaments with well-ordered lamellar structures, which play a role in maximizing oxygen diffusion.

Detailed explanation-3: -Lamellae (primary and secondary) give the gill a large surface area increasing the rte of diffusion and therefore gas exchange. The counter-current exchange system makes gas exchange extremely efficient. Fish are able to extract a much higher proportion of oxygen from water than most animals can form air.

Detailed explanation-4: -Gills in fish Exchange of gases in fish is very efficient because of: the large surface area of the gills. the large surface area of the blood capillaries in each gill filament. the short distance required for diffusion – the outer layer of the gill filaments and the capillary walls are just one cell thick.

Detailed explanation-5: -These gill filaments absorb oxygen from the water and move it into the bloodstream. The fish’s heart pumps the blood to distribute the oxygen throughout the body. At the same time, waste carbon dioxide in the blood passes out through the gills into the water.