Digestive System
Digestive- the way the body converts food into nutrients for the body.
Humans
- 6 main parts of digestion in mammals- The humans first begin digestion by using their teeth to break down the food into particles. These particles are broken down even more by saliva and is sent down the esophagus and towards the stomach. The stomach machanically breaks it down and uses a few acids to break the food down even more. Then the food is sent down into the small intestine, where the nutreints are absorbed and sent out into the body. From there, the food is sent to the large intestines, where the majority of the water is absorbed. Finally, it is sent to the rectume to be excreted.
Mollusks- (cuttlefish) -The beak breaks down food. Then it goes down the esophagus, then the food is broken down even more in the stomach,then through the small intestines, the majority of the nutreints are absorbed. then the food is pushed to the large intestines, where the water is extracted and is finally sent to the rectum for excretion.
Amphibians- Frog- mouth breaks down food, saliva breaks down starches and adds liquid to th the food, food is swallowed in the esophagus, then the food is physically broken down in the stomach, then the food nutrients are absorbed in the small intestines, and the outer is absorbed in the large intestines, the it is excreted.
Arthropods- Arthropods are carnivores, herbivores, detritus feeders, filter feeders, and parasites. The paired appendages around the mouth of Arthropods are usually specialized in accordance with the particular diet of the animal. For example, ma
ny butterflies have mouthparts adapted for sucking out the nectar in flowers. There are so many different ways of feeding in this phylum, that there are also different types of digestive systems. Each arthropod has a different digestive system correlating to their method of feeding and body structure.
The Butterflies Digestive system is located in the abdomen and is generally well hidden. The butterfly only eats and feeds on liquids: nectar, dissolved pollen, liquefied dung, sweat, mineral water, bodily fluids from decomposing animal corpses, and in some very rare cases even alligator tears. The butterfly then digests and extracts proteins and other minerals from these foods.
Some pump digestive enzymes from the midgut into the prey and then suck the liquefied tissues of the prey into the gut, eventually leaving behind the empty husk of the prey. Others grind the prey to pulp using the chelicerae and the bases of the pedipalps, while flooding it with enzymes; in these species the chelicerae and the bases of the pedipalps form a preoral cavity that holds the food they are processing. The spider's stomach acts as a pump that sends food deeper into the spiders digestive system. The spiders midgut bears most of its smaller intestine, where the nutrients is extracted from their food. Most spiders convert nitrogenous bases into uric acid, which can be excreted as dry material. Spiders use "little tubes" called Malpighian tubules to extract these wastes from the blood in the hemocoel and dump them into the cloacal chamber, from which they are expelled through the anus.
For the scorpion, digestion begins outside the mouth. The food is semi-digested by digestive juices that are supplied to the preoral cavity by the gut, before it enters the scorpion's mouth. Setae, which is in the preoral cavity, filter indigestible material such as prey exoskeleton. These indigestible particles are matted together and expelled. Food passes from the mouth to the pharynx to the esophagus to the midgut to the hind gut and is finally expelled through the anus.
reptiles- The digestive system of modern reptiles is similar in general plan to that of all higher vertebrates. It includes the mouth and its salivary glands, the esophagus, the stomach, and the intestine and ends in a cloaca. And the system is fairly similar to modern humans.
echinoderms- Echinoderms have a very simple one-way digestive system, very unlike amphibians. They have intestines and at least one stomach(which are both located in the “central disk” so they don’t
drift in to the limbs), a mouth (with several jaws), and an anus. The mouth is usually beneath the animal and the anus is typically on top. Some seastars, for instance, can push their stomach on the outside of their body and swallow things with it that wouldn’t normally fit into their mouth. When this process occurs, the seastar traps the organism and excretes digestive enzymes on it. Some echinoderms are herbivores and some are carnivores; Their diet affects their bodily structure in certain ways.
http://w3.shorecrest.org/~Lisa_Peck/MarineBio/syllabus/ch7invertebrates/Invertwp/2007/tj/digest.html
Annelids- Unsegmented gut that leads along the middle of the body, directly from the mouth to the anus. Between the wall and the gut is the coelom. The coelom is a fluid-filled body cavity that performs skeletal functions. The coelom segments are separated by thin tissue, called septa, which are perforated by the gut and blood vessels.
