Herbs and their Scientific Names - PPT

 

HUMAN DIGESTIVE SYSTEM-PART 2

HUMAN DIGESTIVE SYSTEM-PART 2

BIOLOGY

Oesophagus is a narrow tube and connects pharynx and somach. It has both volume and involuntary muscles. These muscles are arranged circularly and longitudinally.

Internally, the wall of esophagus is lined with a mucous membrane which secretes mucous. Mucous acts as a lubricant and helps in the easy and smooth passage of food.

Swallowing means pushing food into oesophagus, is a voluntary act. Once food enters oesophages, swallowing becomes an involuntary act.

When food enters into oesophages, the muscles present in its wall contract and relax alternately producing wave like movements. These are called peristaltic movements.

They help in pushing the food down the oesophagus into the stomach. Peristaltic movements of oesophagus are involuntary. There are no digestive enzymes in oesophagus. Oesophagus is only a passage through which food enters into stomach.

Hence, food does not undergo any change in pharynx and oesophagus. However, amylase present in the saliva continues to act on the starch present in the food.

THANKYOU,
NANDITHA AKUNURI