DEFINITIONS+OF+THE+DIGESTIVE+SYSTEM

ACTIVITIES: .- **Epiglottis**: It is a valve or "flap"that act as a cover and prevents the food from going into the respiratory tract. .- **Cardial sphincter.** It is the orifice which connects the oesophagus to the stomach.
 * .- Pylorus:** It is the orifice that connects the stomach to the small intestine.

- A **food bolus** is a mixture of **chewed up food and saliva.** .- **Chyme** is a semi-liquid substance resulting from mixing th**e food bolus with gastric juices.** .- **Chyle** is the substance **resulting from the action of the intestinal juices, bile and pancreatic juices on the chyme.** .- **Egestion** is the process of elimination the undigested substances in the form of faeces /fisis/.

.- **Nutrition** is an involuntary process. Food is ingested and then transformed into nutrients. This nutrients will be incorporated into our own structures. .- **Mechanical or physical digestion** is the series of processes which break down the food into smaller fragments, with the help of the teet. .- **Chemical digestion** is the process that transform food into nutrient substances by the action of digestive juices.