Esophageal reflux L3

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Questions and Answers

What is the process of cutting and grinding food in the mouth called?

Digestion

Deglutition

Mastication (correct)

Peristalsis

Which cranial nerve innervates the chewing muscles?

CN-XII (12th cranial nerve)

CN-IX (9th cranial nerve)

CN-V (5th cranial nerve) (correct)

CN-VII (7th cranial nerve)

What is the role of the lower esophageal sphincter?

Controlling food propulsion in the esophagus

Preventing reflux of stomach contents into the esophagus (correct)

Aiding in absorption of nutrients

Regulating bile secretion

What is achalasia?

A disorder characterized by difficulty swallowing due to esophageal muscle dysfunction Signup and view all the answers

Which nerve controls the movement of the esophagus during swallowing?

Vagus nerve (CN-X) Signup and view all the answers

What type of digestion occurs in the mouth?

Mechanical digestion by teeth and chemical digestion by saliva Signup and view all the answers

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

To prevent gastric juices from refluxing into the esophagus Signup and view all the answers

What is the physiological basis of achalasia?

Pathology or absence of the myenteric plexus containing VIP & NO in the lower third of esophagus Signup and view all the answers

What is a potential consequence of untreated achalasia?

Severe substernal pain and ulceration of the esophageal mucosa Signup and view all the answers

What is a characteristic feature of gastroesophageal reflux disease (GERD)?

Incompetence of the lower esophageal sphincter (LES) leading to reflux of gastric contents into the esophagus Signup and view all the answers

How does the LES prevent reﬂux of gastric secretions into the lower portion of the esophagus?

+ve intra-abdominal pressure closure preventing high pressure in stomach from forcing its contents into esophagus Signup and view all the answers

What regulates contraction and relaxation of the circular musculature of the lower esophageal sphincter (LES)?

Nerves, hormones, and neurotransmitters Signup and view all the answers

Which ONE of the following nerves does not transmit signals from the swallowing center to the pharynx and esophagus?

6th Signup and view all the answers

The process of mastication is initiated by:

Inhibition of the muscles of mastication Signup and view all the answers

Which one of the following increases the tone of the lower esophageal sphincter?

Gastrin Signup and view all the answers

Respiratory inhibition occurs in which phase of swallowing?

Pharyngeal Signup and view all the answers

What is Achalasia?

A condition due to high resting pressure at the LES that fails to relax during swallowing. Signup and view all the answers

What are the functions of Mastication (chewing)?

All of the above Signup and view all the answers

What is the role of salivary amylase in digestion?

It begins carbohydrate digestion Signup and view all the answers

Which stage of swallowing involves muscle contractions to prevent food from entering the nasal cavities, trachea, and esophagus?

Pharyngeal stage Signup and view all the answers

What initiates the cycle of biting, swallowing, and chewing again?

Chewing reflex and stretch reflex Signup and view all the answers

Which teeth are primarily used for cutting food?

Incisors Signup and view all the answers

Where is the swallowing reflex controlled?

Lower pons and medulla Signup and view all the answers

What are peristaltic waves involved in during swallowing?

Moving food through the esophagus Signup and view all the answers

Which cranial nerves are involved in transmitting motor impulses to the pharynx and upper esophagus during the swallowing process?

5th, 9th, 10th, and 12th Signup and view all the answers

What initiates secondary peristalsis in the esophagus?

When primary peristalsis fails to move the food bolus to the stomach Signup and view all the answers

Which nerves innervate the striated muscles of the upper third of the esophagus?

Vagus and glossopharyngeal nerves Signup and view all the answers

What is the function of the upper esophageal sphincter (UES)?

Prevents food and air from entering the esophagus from the mouth Signup and view all the answers

What controls the lower esophageal sphincter (LES)?

Vagus nerve Signup and view all the answers

Study Notes

The pharyngeal stage of swallowing is initiated by sensory impulses from the mouth received by the nucleus tractus solitarius (NTS) via the trigeminal and glossopharyngeal nerves, specifically at the most sensitive areas around the pharyngeal opening including the tonsillar pillars.
This sensory input triggers the swallowing center in the medulla and lower portion of the pons to automatically initiate the swallowing process, which includes motor impulses transmitted to the pharynx and upper esophagus via the 5th, 9th, 10th, and 12th cranial nerves and superior cervical nerves.
During the pharyngeal stage, the swallowing center inhibits the respiratory center to prevent respiration, allowing the food bolus to pass through the pharynx and upper esophagus without entering the trachea.
The esophageal stage of swallowing begins after the pharyngeal stage and is primarily controlled by the swallowing reflex but also the enteric nervous system (ENS) when the vagus nerve is severed.
During the esophageal stage, the esophagus serves as a conduit to move food from the pharynx to the stomach. The esophagus has striated muscles innervated by the vagus and glossopharyngeal nerves in the upper third and smooth muscles controlled by the vagus in the lower two thirds.
The esophagus exhibits primary and secondary peristalsis. Primary peristalsis is a continuation of the wave that begins in the pharynx and moves food to the stomach in 8-10 seconds. Secondary peristalsis is initiated when primary peristalsis fails to move the food bolus to the stomach.
Esophageal secretions, including mucus, lubricate the esophagus and protect it against acidic juices of the stomach.
The esophagus is guarded by two sphincters: the upper esophageal sphincter (UES) and the lower esophageal sphincter (LES). The UES is a voluntary muscle that prevents food and air from entering the esophagus from the mouth. The LES is a circular muscle that guards the entrance into the esophagus from the stomach. It is formed of skeletal muscle but is not under voluntary control.

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Description

Test your knowledge of the pharyngeal stage of swallowing with this quiz. Learn about the nervous initiation and sensory impulses involved in this crucial stage of swallowing.