Functions of the Lower Esophageal Sphincter

The video tutorial explains the swallowing process, which consists of three phases: oral, pharyngeal, and esophageal. The oral phase is voluntary and involves the formation and movement of the bolus. The pharyngeal phase is involuntary, triggered by the bolus touching the oropharyngeal wall, leading to a series of reflex actions. The esophageal phase involves peristalsis, with primary and secondary types ensuring the bolus reaches the stomach. The esophagus is divided into sphincters that prevent reflux, with mechanisms to maintain their contraction.

What is the primary function of the nasopharynx during swallowing?

• To produce saliva

• To allow air passage

• To close and prevent food from entering the nasal cavity

• To assist in chewing

Which cranial nerves are essential for the proper functioning of the oral phase?

• 8th, 9th, and 10th cranial nerves

• 1st, 2nd, and 3rd cranial nerves

• 4th, 6th, and 11th cranial nerves

• 5th, 7th, and 12th cranial nerves

What triggers the pharyngeal phase of swallowing?

• The bolus touching the oropharyngeal wall

• The bolus entering the esophagus

• The bolus being chewed

• The bolus being formed in the mouth

Which of the following is NOT a function of the laryngeal muscles during swallowing?

• Flipping back the epiglottis

• Producing sound

• Closing the laryngeal opening

• Pulling the larynx upward and anteriorly

What is the main difference between primary and secondary peristalsis?

• Primary peristalsis occurs in the stomach, secondary in the esophagus

• Primary peristalsis is preceded by oral and pharyngeal phases, secondary is not

• Primary peristalsis is voluntary, secondary is involuntary

• Primary peristalsis is slower than secondary

What role does secondary peristalsis play in the esophagus?

• It clears the esophagus of any remaining food or refluxed gastric contents

• It initiates the swallowing reflex

• It assists in the voluntary phase of swallowing

• It helps in the formation of the bolus

What is the function of the lower esophageal sphincter (LES)?

• To aid in the digestion of food

• To produce digestive enzymes

• To allow air to enter the stomach

• To prevent acid reflux from the stomach into the esophagus

What happens to the lower esophageal sphincter during swallowing?

• It contracts to prevent food from entering the stomach

• It relaxes to allow the bolus to pass into the stomach

• It produces saliva

• It closes to prevent air from entering the esophagus

Which of the following helps maintain the contraction of the lower esophageal sphincter?

• Diaphragmatic fibers

• Jaw muscles

• Facial muscles

• Tongue muscles

What can happen if the lower esophageal sphincter fails to remain contracted?

• Acid from the stomach can enter the esophagus, causing damage

• The esophagus will produce more saliva

• Food will not enter the stomach

• Air will enter the esophagus