© 2015 Pearson Education, Inc.

Functions of the Digestive System and Organs of the Gastrointestinal tract Pages 463-472

The Digestive System Functions Ingestion- taking in food Digestion- breaking food down Absorption- nutrients into the bloodstream Defecation—elimination of indigestible waste © 2015 Pearson Education, Inc.

Organs of the Digestive System Two groups: Alimentary canal (gastrointestinal or GI tract)— continuous, coiled, hollow tube (aka gut) These ingest, digest, absorb, defecate Accessory digestive organs Includes teeth, tongue, salivary glands, pancreas, liver, gall bladder © 2015 Pearson Education, Inc.

Mouth (oral cavity) Parotid gland Sublingual gland Tongue Figure 14.1 The human digestive system: Alimentary canal and accessory organs. Mouth (oral cavity) Parotid gland Sublingual gland Tongue Salivary glands Submandibular gland Pharynx Esophagus Stomach Pancreas (Spleen) Liver Gallbladder Transverse colon Duodenum Descending colon Small intestine Jejunum Ascending colon Ileum Large intestine Cecum Sigmoid colon Rectum Appendix Anus Anal canal

Organs of the Alimentary Canal a continuous, coiled, hollow tube (about 30ft) runs through the ventral cavity from stomach to anus: Structures include: Mouth Pharynx Esophagus Stomach Small intestine Large intestine Anus © 2015 Pearson Education, Inc.

Functions of the Mouth Mastication (chewing) of food Tongue mixes masticated food with saliva initiates swallowing Taste buds are specialized epithelial cells called gustatory cells Contain taste receptors © 2015 Pearson Education, Inc.

Figure 14.2b Anatomy of the mouth (oral cavity). Upper lip Gingivae (gums) Hard palate Soft palate Uvula Palatine tonsil Oropharynx Tongue (b)

Pharynx Food/fluid moves from the mouth into the: Oropharynx Laryngopharynx Peristalsis: the mechanism that propels food and fluid through these parts of the pharynx © 2015 Pearson Education, Inc.

Figure 14.2a Anatomy of the mouth (oral cavity). Nasopharynx Hard palate Soft palate Oral cavity Uvula Lips (labia) Palatine tonsil Vestibule Lingual tonsil Oropharynx Lingual frenulum Epiglottis Tongue Laryngopharynx Hyoid bone Esophagus Trachea (a)

Esophagus (Gullet) Runs from pharynx to stomach through the diaphragm (about 10 inches long) Relies on peristalsis to move food and fluids to the stomach © 2015 Pearson Education, Inc.