Respiration In Fish N Frog 2d683a

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Aquatic animals such as fish have specialised respiratory structure called gills for breathing A fish have 4 pairs of gills which are covered by the operculum Each gill consists of a small rod of bone called gill arch Each gill arch consists of double row of gill filaments.

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The surface of gill filaments has many platelike projections called lamella to increase surface area The gill lamella are richly supplied with a network of blood capillaries for gaseous exchange

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Many plate-like projections ( lamella) ~increase the surface area for gaseous exchange Thin epithelial walls of the gill filaments ~allows oxygen to diffuse easily into the blood capillaries A network of blood capillaries ~increase the rate of gaseous exchange by diffusion

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The breathing mechanism in fish involves the movement of the operculum and the floor of the mouth to create the flow of water into the mouth cavity and through the gill slits

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~ Mouth open ~Floor of mouth is lowered ~ Volume of pharynx cavity increases ~ pressure in the mouth cavity decrease ~outside pressure higher then presses the operculum to close ~water enter the mouth

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~ mouth closes ~ floor of the mouth is raised ~volume of pharynx cavity decreases ~pressure in the mouth cavity increase ~operculum opens ~water flows through the gills ~ gaseous exchange occur ~water flows out through the operculum

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Dissolved oxygen diffuse through the gill epithelium into the blood capillaries at the gill filaments Carbon dioxide diffuses from the blood capillaries into the surrounding water The direction of the water flow over the gill lamella is opposite to the flow of the blood in order to maximize the rate of diffusion from water into the blood capillaries.

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Give & explain 3 adaptation of gill filaments for gaseous exchange.

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Many plate-like projections ( lamella) ~increase the surface area for gaseous exchange Thin epithelial walls of the gill filaments ~allows oxygen to diffuse easily into the blood capillaries A network of blood capillaries ~increase the rate of gaseous exchange by diffusion

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Give & explain 3 adaptation of gill filaments for gaseous exchange.

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Amphibians such as frogs breathe through skin, mouth and lungs In the water, the frog’s skin functions as the respiratory surface for gaseous exchange

Adaptations of skin for gaseous exchange: 1. Its thin skin allow gases to diffuse easily 2. Its moist skin dissolve gaseous and allow the exchange of gases to occur readily 3. Supplied with many blood capillaries to increase the rate of diffusion & transportation of oxygen & carbon dioxide 

Adaptations of mouth for gaseous exchange: 1. The floor of the mouth cavity always move up & down to enable the air to enter into the mouth through the nostrils 2. Thin lining of the mouth cavity with many blood capillaries increase the rate of diffusion of oxygen & carbon dioxide in the mouth 

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The frog breathes through its lungs when it is active The lungs of the frog consist of a pair of air sacs in the thoracic cavity

The inner walls of the lung are folded to increase the surface area & hence, increase the rate of diffusion of gases 2. Thin walls of the lungs allow the gases to diffuse readily 3. A layer of moisture on the walls of the lungs enable the oxygen to dissolve in it before diffusing across the wall 4. A network of blood capillaries on the walls of the lungs to increase rate of diffusion & transportation of oxygen & carbon dioxide 1.

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~floor of the mouth lowers ~volume inside mouth increases ~pressure inside decrease ~air enters through nostrils into the mouth ~nostril closes ~floor of the mouth is raised up ~pressure increases ~ glottis opens ~air es into the lungs ~gaseous exchange occurs

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~nostril opens ~ air flows out of the mouth ~lungs bulge upwards ~glottis opens ~lung shrink due to its elasticity ~air flows out