Activity 5: Digestive System
It consists of organs and structures that work together to break down food, absorb nutrients, and eliminate waste.

✿ Tooth – hard, calcified structures located in the oral cavity and each tooth has an enamel-covered crown, a dentin layer beneath the enamel, and a pulp cavity containing nerves and blood vessels; for mechanical digestion

✿ Duodenum – first section of the small intestine, receiving partially digested food from the stomach; for chemical digestion, mixing chyme with bile, pancreatic enzymes, and intestinal juices to continue the breakdown of nutrients

✿ Liver – a large, reddish-brown organ located in the upper right abdomen, has a unique blood supply from the hepatic artery and portal vein, and is composed of lobules; produces bile for fat digestion, detoxifying substances, storing vitamins and glycogen, and synthesizing blood proteins

✿ Frog Stomach c.s. – a layered structure: mucosa, submucosa, muscularis, and serosa; does both mechanical and chemical digestion, using muscular contractions to mix food with gastric juices containing enzymes and acids

✿ Tonsil – lymphoid tissues located at the back of the throat. They contain lymphocytes and macrophages to help defend against inhaled or ingested pathogens

✿ Esophagus – muscular tube connecting the throat to the stomach; it transports food and liquids to the stomach through coordinated muscle contractions called peristalsis

✿ Gallbladder – small, pear-shaped organ beneath the liver which stores and concentrates bile produced by the liver; releases bile into the duodenum to aid in the digestion and absorption of fats

✿ Appendix – small, tube-like structure attached to the cecum, part of the large intestine; exact function is not entirely clear, it is thought to play a role in gut immunity by housing beneficial bacteria

✿ Parotid Gland – one of the major salivary glands, located near the ear; secretes saliva in the mouth

✿ Cecum – a pouch-like structure at the beginning of the large intestine, connecting the ileum to the colon; absorbes fluids and salts that remain after intestinal digestion and absorption, and it houses a large number of bacteria involved in the fermentation of undigested carbohydrates