Act 18: Invertebrates Digestion and Neural

• 2 types of Digestive System: Complete and Incomplete
• Gastrovascular cavity - sac like structure with only one opening (incomplete)
• Digestive tract/alimentary canal - a long tube that has two openings (complete)
• A complete digestive system has 7 regions: mouth, pharynx, esophagus, stomach, small intestine, large intestine, and rectum.
• Peristalsis - contraction of muscular walls from the mouth to digestive tract
• 3 sections of cockroach: foregut, midgut, hindgut
• foregut: mouth, pharynx, esophagus, crop, and gizzard
• midgut: gastric caeca and stomach
• Hindgut: malpighian tube, small and large intestine, rectum
• Pharynx - cavity of mouth
• Esophagus - extension of foregut after pharynx
• Crop - temporary storage of food
• Gizzard - has teethed structure for grinding of food
• Gastric caeca - feather like projection that increase surface area of the gut and also secretes enzyme
• Stomach - or ventriculus
• Malpighian tubules - thread like extensions that absorb water and waste
• Small intestine - further digestion and absorption site
• Large intestine - absorbs more liquid wastes
• Rectum - stores waste until elimination
• Bolus- chewed food
• Pellet - dried feces
• Malpighian tubules - counterpart of kidney