Digestive System The Digestive Pathway Digestive System n

Digestive System The Digestive Pathway

Digestive System n n The digestive system consists of a continuous “one-way” pathway and the accessory organs which function in conjunction with it. Peristalsis – the slow, rhythmic muscular contractions by which food is moved through the digestive system

Mouth n n Ingestion occurs in the mouth Two types of digestion: 1. 2. Mechanical digestion – the teeth physically break down food to increase surface area Chemical digestion – enzymes are used to break down food Salivary amylase is secreted by the salivary glands to help digest carbohydrates

Pharynx n n The pharynx is the open area at the back of the mouth commonly called the throat It is a passageway for both food and air

Esophagus n n The esophagus is the tube that connects the mouth/pharynx to the stomach Peristalsis begins in the esophagus

Stomach n n n The stomach is a muscular organ where food is temporarily stored Food is liquefied to a semi-fluid mass of partially digested food called chyme Protein digestion begins in the stomach

Small Intestine n n The small intestine is a long tube (6. 5 m) where the major portion of digestion and absorption occurs The small intestine contains villi which increase surface area to improve absorption

Large Intestine n n The large intestine is a shorter tube (1. 5 m) where reabsorption of water occurs No digestion occurs here Undigested and unabsorbed materials pass from the small intestine to the large intestine Production and absorption of some vitamins occurs in the large intestine

Rectum n n The rectum is the last 6 -8 inches of the large intestine It stores solid waste

Anus n The anus is where feces is eliminated from the body