5. GAS EXCHANGE IN ANIMALS AND PLANTS ANIMALS: Internal transport systems For gas exchange to reach all parts of the body, animals require a vascular system . A vascular system involves the movement of fluids that transport gases, nutrients, and other materials to the cells of the organism. Most organisms have a circulatory system , which is a vascular system which flows due to muscular control.
6. GAS EXCHANGE IN ANIMALS AND PLANTS ANIMALS: Internal transport at its simplest For unicellular organisms, gases and other substances enter through diffusion . Streaming of the cytoplasm helps distribute materials around the cell. Unicellular organisms do not have blood. Diffusion Cytoplasmic steaming
7. GAS EXCHANGE IN ANIMALS AND PLANTS ANIMALS: Internal transport at its simplest For small multicellular organisms (i.e. planarian), fluid containing dissolved gases, nutrients, and other substances is ingested . The fluid flows freely within the organism’s cavities, sometimes assisted by the organism’s movements . A simple transport system does not require blood.
8. GAS EXCHANGE IN ANIMALS AND PLANTS ANIMALS: The open transport system Open transport system: Blood does not stay contained within blood vessels. Blood bathes cells directly. Blood sloshes back and forth. Most suited to insects like the grasshopper.
9. GAS EXCHANGE IN ANIMALS AND PLANTS ANIMALS: The closed transport system Closed transport system: Blood is completely enclosed in vessels. Blood is pumped by muscular contractions.
10. GAS EXCHANGE IN ANIMALS AND PLANTS ANIMALS: The closed transport system Closed transport system: Earthworms (annelids) Gases diffuse through the skin into the blood vessels. 5 accessory hearts known as aortic arches (thickened blood vessels with muscular walls) contract to pump the blood forward.
11. GAS EXCHANGE IN ANIMALS AND PLANTS ANIMALS: The closed transport system Closed transport system: Fish Gases diffuse through gills into blood. Blood travels through the heart only once during each complete circuit around the body. This is called single circulation .
12. GAS EXCHANGE IN ANIMALS AND PLANTS ANIMALS: The closed transport system Closed transport system: Amphibians Lungs for gas exchange. Blood is pumped from the heart to the lungs, and then back to the heart to be pumped again. Oxygenated blood mixes with deoxygenated blood in the heart. Amphibians make up for this by performing skin respiration . 3-chamber heart
13. GAS EXCHANGE IN ANIMALS AND PLANTS ANIMALS: The closed transport system Closed transport system: Birds and mammals Lungs for gas exchange. Blood is pumped from the heart to the lungs, and then back to the heart to be pumped again. Oxygenated blood DOES NOT MIX with deoxygenated blood in the heart. This is due to a 4-chamber heart 4-chamber heart
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