Ingested food passes through the esophagus and into the hypo- pharynx for temporary storage. Digestive enzymes secreted by the malpighian tubules and the midgut endothelium catabolize macromolecules in the insect's diet. The nutrients are absorbed into the hemolymph through the midgut endothelium. Gastric caecae lie throughout the body cavity collecting and concentrating sulphuric wastes. These tubules empty into the midgut just beyond the cardiac valve.
Rectal pads absorb urea from the fecal pellet before it is excreted through the anus.
Explain how to distinguish between each pair of terms. Taxis and Kinesis. Conditioning and Imprinting. Commissure and Connective. Ovipary and Ovovivipary.