Human Physiology - Introduction to the Digestive System lyrics

William Beaumont and St. Martin Functions The digestive, or gastrointestinal (GI), system is comprised of a long, epithelium-lined tube that is open to the outside world. It serves four primary functions: Absorption Digestion Motility Secretion Anatomy Oral Cavity: first stages of digestion: -chewing -saliva by salivary glands (sublingual, submandibular, parotid) esophagus: food=chyme stomach to an*s: gut stomach: fundus, body, antrum,(rugae), pyloric valve (regulates rate of movement of food into the SI) small intestine: duodenum (.25 m), jejunum and ileum (2.6 m) -enzymes, exocrine secretions by accesory glandular organs (pancreas and liver) that enter in the duodenum, sphincter of oddi -nearly all nutriends and secreted fluids are absorbed large intesting 1.5 l of chyme per day colon: watery chime covnereted to semisolid feces rectum, defecation reflex an*s external an*l sphincter Gastrointestinal Wall Wall has four layers Mucosa: inner lining facing the lumen. Made of