Cricopharyngeal Part of Inferior Pharyngeal Constrictor
Pars cricopharyngea constrictoris inferioris pharyngis
Read moreQuick Facts
Origin: Lateral aspect of cricoid cartilage of larynx.
Insertion: Pharyngeal raphe.
Action: Constriction of mid-pharynx during swallowing.
Innervation: Pharyngeal plexus (CN X).
Arterial Supply: Ascending pharyngeal artery and pharyngeal branches of inferior thyroid artery.
Related parts of the anatomy
Origin
The inferior pharyngeal constrictor muscle is the thickest of the three constrictor muscles. It can be divided into the thyropharyngeus and the cricopharyngeus, which are named according to their laryngeal attachments. The cricopharyngeus muscle originates from the lateral aspect of the cricoid cartilage.
Insertion
Both portions of the inferior pharyngeal constrictor muscle course posteromedially and merge with their contralateral counterpart along the pharyngeal raphe. The cricopharyngeus extends inferiorly and blends with the esophagus (Standring, 2016).
Key Features & Anatomical Relations
There are two potential points of weakness in the inferior region of the insertion of the inferior constrictor. These are Killian’s triangle and Laimer’s triangle and sit above and below the cricopharyngeus, respectively (Standring, 2016).
Actions
The cricopharyngeus part of the inferior pharyngeal constrictor muscle aids in the closure of the upper esophagus. The upper esophageal sphincter sits at the bridge between the hypopharynx and the cervical esophagus. The cricopharyngeus must maintain sustained tonic contraction to permit a basal muscular tone, while retaining the ability in rapid relaxation, as required in swallowing or vomiting (Standring, 2016).
List of Clinical Correlates
- Hypopharyngeal diverticula
References
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.
Learn more about this topic from other Elsevier products
Cricopharyngeus Muscle
Killian's triangle is a pharyngeal weak point formed between the horizontal fibers of the cricopharyngeus (CP) muscle and the oblique fibers of the inferior pharyngeal constrictors (IPCs) and is also known as Killian's dehiscence.
