Esophageal Function and Saliva Role

The video explains the process of digestion starting in the mouth where food is chewed and mixed with saliva to form a bolus. The bolus is then pushed by the tongue towards the pharynx, while the soft palate and epiglottis prevent it from entering the nasal cavity and trachea, respectively. The bolus enters the esophagus, where circular and longitudinal muscles contract and relax in a coordinated manner to push the bolus down to the stomach through a process called peristalsis.

What is the role of saliva in the mouth?

• To transport food to the stomach

• To mix with food and form a bolus

• To break down food into nutrients

• To absorb nutrients

What is the soft mass of food formed in the mouth called?

• Pulp

• Bolus

• Chyme

• Mucus

Which structure prevents food from entering the nasal cavity during swallowing?

• Epiglottis

• Soft palate

• Trachea

• Pharynx

What action does the epiglottis perform during swallowing?

• It pushes the bolus towards the stomach

• It covers the opening to the trachea

• It mixes food with saliva

• It contracts to move the bolus

What type of muscle contractions move the bolus down the esophagus?

• Oscillation

• Peristalsis

• Segmentation

• Churning

Which muscles contract behind the bolus in the esophagus?

• Longitudinal muscles

• Circular muscles

• Oblique muscles

• Sphincter muscles