CBSE Class 9 Answered
During chewing, the lips close forming an anterior seal.
The palate closes against the back wall of the throat separating the oral cavity from the nasal cavity. This action prevents food or liquid from coming up through the nose.
The vocal cords close. This shuts off access to the trachea.
The throat muscles constrict. This occurs in a coordinated manner to help push the food downwards towards the esophagus.
The larynx is pulled upwards and forwards. During this, the epiglottis tilts posteriorly, covering and protecting the vocal cords. The bolus is also directed to the sides by the shape of the epiglottis.
All these are various reflex actions going on in a coordinated manner to bring about the swallowing action, together termed as the swallow reflex.