The Process of Digestion

What is the digestive system? The digestive system is the organs and glands that break food down into chemicals and absorb the chemicals.

The Mouth The mouth is where food enters the digestive system. Mechanical digestion is done by chewing the food into small pieces. Chemical digestion is begun by amylase found in saliva

Salivary Glands Accessory glands in the mouth that produce saliva Contains amylase – breaks down carbohydrates Contains lysozyme – kills bacteria

The Esophagus A muscular tube that connects the mouth and the stomach. Once food is swallowed, it is called a bolus. The bolus is moved by rhythmic contractions of the muscles in the esophagus called peristalsis.

The Stomach A hollow, muscular organ that continues mechanical digestion and starts acidic chemical digestion.

The Stomach Proteins are digested in the stomach. The food released from the stomach into the intestines is called chyme

The Small Intestine A muscular tube covered with villi where chemical digestion is started and nutrients are absorbed. Villi- finger –like folds located in the small intestine that help absorb food Capillaries in the villi absorb protein and carbohydrates. Lymph vessels in the villi absorb fats

Pancreas – Accessory to Small Intestine Makes hormones that regulate blood sugar Insulin – decreases blood sugar level Glucagon – increases blood sugar level Releases enzymes to finish breaking down foods.

Liver – Accessory to the small intestine Produces bile – a mix of lipids and salts that breakdown droplets of fat so the enzymes of the small intestine can break the fat apart.

The Large Intestine / Colon Removes water from the indigestible materials that leave the small intestine.