The Digestive System Esophagus Stomach Small Intestine Liver
Esophagus Muscular tube, lined with moist stratified squamous epithelium that extends from the pharnyx to the stomach. 25 Cm Long Transports food from the pharnyx to the stomach Upper and lower esophageal sphincters are located at the upper and lower ends of the esophagus.
Esophagus (continued….) Esophageal sphincters regulate the movement of food into and out of the esophagus.
Stomach Enlarged segment of the digestive tract in the superior part of the abdomen Lined with simple columnar epithelium. Storage and mixing chamber for ingested food Regulates secretions and could be divided into 3 phases.
Stomach (continued……) Cephalic Phase- sensations of taste, the smell of food, stimulation of the tactile receptions during the process of chewing and swallowing. Gastric Phase- period during which the greatest volume of gastric secretion occurs Intestinal Phase- primarily inhibits gastric secretions
Small Intestine 6 meters long Duodenum-25cm long Jejunum-2.5 m long Ileum-3.5m long Major site of digestion and absorption of food
Small Intestine (continued….) Major function is absorption of nutrients Most occurs in the duodenum and jejunum Mixing and propulsion of chyme occurs here
Liver Weighs about 1.36 kilograms Located in the right upper quadrant of the abdomen Divided into right lobe and left lobe Stores and processes nutrients, detoxifies harmful chemicals
Liver (continued…..) Synthesizes new molecules Neutralizes stomach acid by increasing the efficiency of fat digestion and absorption.