Phylum Arthropoda - General Features

Jointed Appendages

Freely moveable; wide range of motion

Exoskeleton

Rigid outer skeleton made of chitin; provides protection; must be shed for growth

Tagmata

Fused groups of segments (e.g. head, thorax)

Setae

Hair like sensory structures on the exoskeleton

Hemocel

Blood filled cavity (open circulatory system

Tracheae

System of tubes for gas exchange directly to tissues in insects

Spiracles

External openings of tracheal system

Malpighian Tubules

Excretory organs that remove nitrogenous wastes from hemolymph

Gastric Mill

Hard structure in stomach that grinds food