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Animal Systems. Feeding and Digestion Respiration Circulation Excretion. Feeding and digestion. How does digestion occur? How are mouthparts adapted for different diets?. Ways of obtaining food.
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Animal Systems Feeding and Digestion Respiration Circulation Excretion
Feeding and digestion How does digestion occur? How are mouthparts adapted for different diets?
Ways of obtaining food • Filter Feeders- Catch algae and small animals by using modified gills, or other structures as a net to filter food items out of the water. • Ex. Sponges, Barnacles, Whales • Detrivores- Feed off of decaying organic matter. • Ex. Earthworms • Carnivores- Consuming other living organisms. • Ex. Whales, Spiders, Lions • Herbivores- Consuming plants, or parts of trees for energy. • Ex. Birds, Sea Slug • Parasitism- Dependence on another animal for energy • Ex. Flatworms, Roundworms
Processing Food • A digestive tract has two openings, one to ingest food, and one to expel wastes. • Digestion begins in the mouth. • Mechanical Digestion • How are carnivores teeth different from herbivores? • Chemical Digestion • In humans we start breaking down complex sugars in the mouth, using salivary amylase
Digestion • Carnivores typically have short digestive tracts that produce fast acting meat digesting enzymes • No animal produces digestive enzymes that are able to break down the cellulose in plant tissues • Herbivores have very long intestines with specialized pouches, some containing symbiotic bacteria that digest cellulose • Ex. Cows, have an extension in their esophagus called a Rumen, it regurgitates food that has been digested there, where the animal chews it again and re-swallows it. “chewing the cud”
Human Digestive System Why do we need to eat? What nutrients does your body need? What is a balanced diet?
Energy Food contains energy our body needs to carry out its functions Laboratories measure the calories (energy) found in food by heating it up A calorie (lower case c) is the amount of energy needed to raise the temperature of water by 1 degree Celsius A dietary Calorie is equal to 1000 “calories”
Nutrients There are about 45 substances found in food that your body does not make itself, therefore we need to consume it somehow. Water, the body needs water to carry out cell processes, it makes up most of your blood, and extracellular fluid. Water is lost even when we breath On hot days we need to drink more fluids than normally to replace those lost through sweat.
Carbohydrates Found in many things you wouldn’t think Carbs are in the sugars found in fruits, grains, potatoes, milk
Fats Usually people associate fat in their diet as a bad thing, but we actually need it If you don’t get enough you may not be able to absorb some essential vitamins found in foods Organs wouldn’t be insulated
Proteins Supply minerals for growth and repair