Muscle
Pharyngeal constrictor muscles
Overlapping muscles that propel a swallowed bolus
High-yield
Most constrictor fibers meet at the posterior median raphe. Cricopharyngeus is a major muscular component of the upper esophageal sphincter, rather than the whole sphincter mechanism.
Overview
The superior, middle and inferior constrictors wrap around the pharyngeal wall. Their overlapping sheets narrow the passage in a coordinated sequence during swallowing. The inferior muscle overlaps the middle externally, and the middle overlaps the superior.
Reference facts
- Origin
- Superior: medial pterygoid region and hamulus, pterygomandibular raphe and posterior mylohyoid line. Middle: hyoid horns and stylohyoid ligament. Inferior: thyroid oblique line and cricoid cartilage
- Insertion
- Mainly the posterior median pharyngeal raphe, extending superiorly to the pharyngeal tubercle; cricopharyngeal fibers form a posterior sling
- Innervation
- CN X via the pharyngeal plexus; superior and recurrent laryngeal branches also contribute to the inferior constrictor
- Action
- Coordinated contraction advances the bolus; cricopharyngeus maintains resting sphincter tone and relaxes during swallowing
- Blood supply
- Ascending pharyngeal, facial and maxillary branches; thyroid arterial branches also supply the lower region
Clinical correlation
Zenker diverticulum is a mucosal and submucosal pouch near the junction of thyropharyngeus and cricopharyngeus. It may cause dysphagia, return of retained food and bad breath. The region called Killian’s dehiscence is not a consistently demonstrable open gap in normal specimens.
Frequently asked questions
What do the pharyngeal constrictor muscles do?
Coordinated contraction advances the bolus; cricopharyngeus maintains resting sphincter tone and relaxes during swallowing.
What nerve innervates the pharyngeal constrictor muscles?
CN X via the pharyngeal plexus; superior and recurrent laryngeal branches also contribute to the inferior constrictor.
Where do the pharyngeal constrictor muscles attach?
Origin: Superior: medial pterygoid region and hamulus, pterygomandibular raphe and posterior mylohyoid line. Middle: hyoid horns and stylohyoid ligament. Inferior: thyroid oblique line and cricoid cartilage. Insertion: Mainly the posterior median pharyngeal raphe, extending superiorly to the pharyngeal tubercle; cricopharyngeal fibers form a posterior sling.
What is the blood supply of the pharyngeal constrictor muscles?
Ascending pharyngeal, facial and maxillary branches; thyroid arterial branches also supply the lower region.