Esophagus Anatomy and Physiology

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Which cranial nerve is responsible for the innervation of the Parotid gland?

X cranial nerve

VII cranial nerve

IX cranial nerve (correct)

V3 cranial nerve

What is the primary function of the propulsive contractions mediated by the PS nerves in the myenteric plexus?

To mix the substances

To move the bolus further along the tube (correct)

To slow down the movement of the chyme

To relax the muscles of the tongue

Which muscles are responsible for mechanical homogenization during the oral phase of swallowing?

Extrinsic lingual muscles

Muscles of the palate

Muscles of the jaw

Intrinsic lingual muscles (correct)

How long does it take for the bolus to travel from the pylorus to the ileocecal valve?

3-5 hours Signup and view all the answers

Which nerve provides innervation to the mandibular muscles of the jaw?

V3 cranial nerve Signup and view all the answers

What is the location of the submucosal plexus in the intestinal wall?

Submucosa Signup and view all the answers

What is the function of the myenteric plexus in the intestinal motility?

Mixing and propulsion of food Signup and view all the answers

What type of muscle is innervated by the myenteric plexus?

Smooth muscle Signup and view all the answers

What is the role of mechanoreceptors in the myenteric plexus?

Modulation of the autonomic nervous system Signup and view all the answers

What is the diameter range of the fibres that interconnect the two muscle layers in the intestinal wall?

2-10 microns Signup and view all the answers

Which type of neurons carry sympathetic fibres to the myenteric and submucosal plexuses?

Postganglionic neurons Signup and view all the answers

What is the primary function of the myenteric plexus?

Motility Signup and view all the answers

What is the effect of the submucosal plexus on the submucosal muscle?

Contractions Signup and view all the answers

What is the purpose of segmentation contractions in the gastrointestinal tract?

To mix the contents of the chyme and increase absorption Signup and view all the answers

What is the effect of VIP (vasoactive intestinal peptide) on the pyloric sphincter and the ileocecal valve?

Relaxation Signup and view all the answers

What is the primary mechanism by which the central nervous system influences primary peristalsis in the esophagus?

Through the stimulation of the vagus nerve Signup and view all the answers

What is the role of VIP and NO in secondary esophageal peristalsis?

They are relaxants of the circular muscle layer Signup and view all the answers

What is the response of the esophageal muscle layers above the bolus level during secondary peristalsis?

Circular layer contraction, longitudinal layer relaxation Signup and view all the answers

What is the primary function of the dorsal motor nucleus in the context of esophageal peristalsis?

To innervate the smooth muscle of the esophagus Signup and view all the answers

What is the trigger for the activation of secondary esophageal peristalsis?

The failure of primary peristalsis to clear the bolus Signup and view all the answers

What type of muscle is present in the upper third of the esophagus?

Striated muscle Signup and view all the answers

Which nerves are responsible for the innervation of the striated muscle in the upper esophagus?

IX and X cranial nerves Signup and view all the answers

What is the name of the muscle that relaxes to allow the passage of food into the esophagus?

Cricopharyngeal muscle Signup and view all the answers

What is the term for the peristalsis that occurs in response to esophageal distension?

Secondary peristalsis Signup and view all the answers

How long does it take for the food bolus to pass through the esophagus?

5-10 seconds Signup and view all the answers