Parts of the Digestive System

Activity 2

Watch the video and tick the sentences you hear:

 Food in the mouth is mixed with saliva.

 Saliva and the teeth begin to digest the food.

 Food is forced back into the throat, pharynx, by the tongue.

 Food in the pharynx stimulates the swallowing reflex.

 The epiglottis opens and let the food pass.

 Food goes from the pharynx to the oesophagus.

 Food moves down the oesophagus by peristalsis.

 The stomach has muscular walls that break the food into smaller pieces.

 Chyme exits through the pyloric sphincter into the duodenum of the small intestine.

 The absorption takes place in the jejunum.

 The mucosa does not produce enzymes.

 This completes the chemical process of digestion.

 The structure of each villus contains a capillary and lacteal to pick up the digestive nutrients.

 The nutrients are now transported by the blood to all the cells of the body.

 Mass peristalsis pushes the faeces into the rectum.

Once you have finished, work in pairs and compare your answers. You must discuss them and meet an agreement.

VIDEO SCRIPT

In digestion food is changed by organs into a soluble form to be absorbed by the body.

Food in the mouth is mixed with saliva. Saliva begins to dissolve the food as the teeth grind and cut it.

Food is forced back into the throat pharynx by the langue. Food and the pharynx stimulate the swallowing reflex.

The larynx is pulled upward to meet the epiglottis and seal off the trachea. Food goes from the pharynx to the oesophagus.

Food moves down the oesophagus by peristalsis. The peristaltic wave reaches the oesophageal sphincter and food enters the stomach. The unique muscular structure of the stomach breaks up the food into small pieces called chyme. Chyme exits through the pyloric sphincter into the duodenum of the small intestine.

The major portion of absorption and digestion occurs in the small intestine. The mucosa secretes enzymes that supplement the digestive enzymes of the pancreas and the liver. This completes the chemical process of digestion.

The walls are covered by villi where nutrient absorption takes places. The structure of each villus contains the capillary and lacteal to pick up the digested nutrients. The nutrients are now transported by the blood to all the cells of the body.

The undigested food reaches the ileocecal valve and enters the large intestine or colon.

The colon absorbs water, manufactures vitamins, produces mucous and forms and expels feces.Mass peristalsis pushes the feces into the rectum which stimulates the defecation reflex.