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41 Cards in this Set
- Front
- Back
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animal's fuel is managed by:
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the human body
example: glucose regulation |
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essential nutrients
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substances that the animals cannot make for itself from any raw materials and therefore must obtain in a prefabricated form
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Amino acids
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20 amino acids
most animals can make half of these 8 essential amino acids |
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Fatty acids
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essential fatty acids we can't make include linoleic acids
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Vitamins
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organic molecules that act as co-enzymes
13 essential vitamins taht are esential to humans |
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Minerals
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Ions we need to take
ex. calcium and iron |
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Filter feeders
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sift small food paritcles from the water ex. Baleen whales
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Substrated feeders
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live in or on their food source, eating their way through food ex. maggots
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fluid feeders
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make their living sucking nutrient rich fluids from a living host ex. Mosquitos leeches, hummingbirds
are considered parasites |
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Bulk feeders
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eat relatively large pieces of food ex. snakes, humans
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4 main stages of food processing
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Ingestion
Digestion Absorption Elimination |
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Ingestion
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the act of eating is only the first stage of food processing
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Digestion
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Second stage, breaking food down into molecules small enough for the body to absorb
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Absorption
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Cells take th molecules out of digestive system
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Elimination
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Undigestable material has to be eliminated
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Intracellular digestion
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unusual for animals b/c hydrolytic enzymes break down food w/out digesting the cells cytoplasm
only in the prorifera kingdom i.e. sponges |
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Extracellular by hydrolysis
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breakdown food outside cells
Gastrovascular cavities- digestive sacs only in the cnidarians(jellyfish) and flatworms |
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Complete digestive tract-alimentary canal
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mouth, digestive tubes, anus
Food moves in one direction so it is specialized |
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In mamalian digestive systems food moves by:
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Peristalsis
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Parts are closed off by:
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sphincters
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Accesory organs
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Salivary glands
Pancreas Liver Gallbladder |
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Oral Cavity
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presence of food triggers functions
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teeth
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process food
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salivary amylase
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enzyme that hydrolyzes stach and glycogen into small polysaccharides
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Bollus
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ball of food that the tongue rolls into
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Pharynx
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closes off windpipe, it opens to the esophagus and trachea
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Esophagus
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conducts food from the pharynx down to the stomach by peristalsis
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Stomach
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located in the upper abdominal cavity
stores food and performs preliminary digestion |
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gastric juices
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contian hydrochloric acid from pareital cells and the enzyme pepsin from chief cells
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acid chyme
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the stomach contents becmoe a nutrient rich broth which is acid chyme
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pyloric sphincter
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opening from the stomach to the smal intestine
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small intestine
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major organ of digestion and absorption
6 meters long and a ph of 8 |
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Duodenum
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where most of digestion occurs
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Jejunum and ileum
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functions to absorb water and nutrients
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Digestion
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occurs maily in the small intestine
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Bile
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bile salts aid in digestion and absorption of fats
It is produced in the liver but STORED in the gallbladder |
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Carbohydrate digestion (starch and glycogen)
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begins in the oral cavity with the enzyme salivary amylase then ocntinues into the small intestine
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protein digestion
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begins in the stomach
proteins are broken p into their amino acids or into small peptides Enzymes-trypsi, chymotrypsi, Dipeptidease etc. secreted by the intestinal epithelium |
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Fat Digestion
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most undigested until it reaches the small intestine
bile salts act to keep them in fat droplets then they are broken down by enzyme lipase that hydrolyzes fat molecules into glycerol fatty acids and glycerides |
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Absorption
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most occurs in the duodenum a large surface area
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in each villus there is:
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a capillary bed or net
a lacteal |
