Swallowing is typically devided into different phases: the oral, pharyngeal and oesophageal phase. The oral phase is when when you place whatever is supposed to be swallowed (food, water, medicine and saliva) in your mouth. The oral phase include masticating, lubrication and forming the food into a uniform unit that is easy to transport, called a bolus. The oral phase is a voluntary process which means you control the necessary muscle work to form the bolus, meaning this phase can be prolonged for as long as required.
The pharyngeal and oesophageal swallowing phases are not voluntary – they are suppressed by the oral phase for as long as transportation isn’t yet necessary. These two phases are executed by a complex and highly coordinated automated muscle work which you can’t control voluntary, which primarily has to function to protect the entrance to the windpipe (glottis) from bolus entering the airways (bolus aspiration/penetration). To efficiently protect the windpipe (trachea), as others have pointed out a flap (epiglottis) is lowered above glottis, the entire voice box (larynx) is also elevated and moved forward in order to protect the windpipe. These are just a few physiological processes occuring more or less simultaneously that protects the windpipe in the involuntary phases. In summary the reason why you can’t interrupt the involuntary phases is because that would increase the risk of bolus penetrating the glottis into the windpipe.
Swallowing is typically devided into different phases: the oral, pharyngeal and oesophageal phase. The oral phase is when when you place whatever is supposed to be swallowed (food, water, medicine and saliva) in your mouth. The oral phase include masticating, lubrication and forming the food into a uniform unit that is easy to transport, called a bolus. The oral phase is a voluntary process which means you control the necessary muscle work to form the bolus, meaning this phase can be prolonged for as long as required.
The pharyngeal and oesophageal swallowing phases are not voluntary – they are suppressed by the oral phase for as long as transportation isn’t yet necessary. These two phases are executed by a complex and highly coordinated automated muscle work which you can’t control voluntary, which primarily has to function to protect the entrance to the windpipe (glottis) from bolus entering the airways (bolus aspiration/penetration). To efficiently protect the windpipe (trachea), as others have pointed out a flap (epiglottis) is lowered above glottis, the entire voice box (larynx) is also elevated and moved forward in order to protect the windpipe. These are just a few physiological processes occuring more or less simultaneously that protects the windpipe in the involuntary phases. In summary the reason why you can’t interrupt the involuntary phases is because that would increase the risk of bolus penetrating the glottis into the windpipe.
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