difference between digestive tract and cavity

• A digestive tract (otherwise known as an Alimentary canal) has two openings (a mouth and anus) between its digestive tubes.

• Food processing occurs within a tube-like enclosure, the alimentary canal, running lengthwise through the body from mouth to anus.

• Examples are insects (cockroach), animals, human beings.

• In digestive tract there are multiple organs to digest the food and then transport it to various areas of the body.

• Different organs have different functions. e.g. liver, stomach, pancreas, small/large intestine ,rectum and so on.

• Different nutrients are differentially extracted during the course of digestion. For example, simple starches are broken down already in the mouth, while protein and fats are extracted in the small intestine. Since the process is both specialized and transit time is longer a tube like system more completely recovers nutrients than would a sack like system.

• A digestive cavity is a digestive sac with only a single opening.

• In digestive cavity, food is ingested and eliminated through the same opening (examples would be hydra, marine jellyfish, and Platyhelminthes, i.e. flatworms).

• Here they have a single opening which leads to a pouch-like cavity serves as both mouth and anus.

• No of openings• Shape • Simple vs complex• Involvement of different organs• Ability to extract nutrients