INFERIOR CONSTRICTOR

ORIGIN
Cricopharyngeus: lateral aspect of arch of cricoid cartilage. Thyropharyngeus: oblique line of laminar of thyroid cartilage and fibrous cricothyroid arch
INSERTION
Cricopharyngeus: continuous with muscle of opposite side, behind pharynx. Thyropharyngeus : lower pharyngeal raphe
ACTION
Aids swallowing . Cricopharyngeus acts as upper esophageal sphincter
NERVE
Pharyngeal plexus (IX, X and sympathetic) via pharyngeal branch of X with its motor fibers from cranial accessory (XI)