DigestionDigestion

• All animals are heterotrophs – they can not can not make their own food

• Digestion – process of breaking down food into smaller molecules that the organism can use

• Absorption – method by which cells take up the digested nutrient molecules

Types of Digestive Tracts

Types of Digestive Tracts

Filter Feeder

Filter Feeder: animals that eat by separating food particles from water

Types of Digestive Tracts

Filter FeederGastrovascular

Cavity

Gastrovascular Cavity: 1 opening where food goes in and wastes go out

Types of Digestive Tracts

Filter FeederGastrovascular

Cavity

Complete Digestive Tract

Complete Digestive Tract: 2 openings where food goes in (mouth) and wastes go out (anus)

•Porifera are filter feeders •They eat bacteria•Cells called ameobacytes carry the nutrients throughout the whole sponge

Porifera - Porifera - SpongesSponges

PLATYHELMINTHES - PLATYHELMINTHES - FLATWORMSFLATWORMS

Flatworms eat tiny crustaceans, protists, or other flatworms depending on their habitat.

ArthropodsArthropods• Arthropods exhibit every type of feeding mode. They include

carnivores, herbivores, detritus feeders, filter feeders, and parasites, and there are specializations within these major categories.

Echinodermata – starfish, etcStarfish digestion is carried out in two stomachs:

the cardiac stomach and the pyloric stomach.

The cardiac stomach, which is a sack like stomach located at the center of the body may be everted—pushed out of the organism's body and used to eat and digest food.

The cardiac stomach is then brought back inside the body, and the partially digested food is moved to the pyloric stomach. Further digestion occurs in the intestine and waste is either excreted through the anus.

http://www.youtube.com/watch?v=rE8l-KFQlhY&feature=related

Starfish eat clams, muscles, oysters

Chordata-Aves

• What do birds eat?

Human Human DigestionDigestion

• What do humans eat?