INFERIOR CONSTRICTOR
Origin
Cricopharyngeus: lat aspect of arch of cricoid cartilage. Thyropharyngeus: oblique line of laminar of thyroid cartilage and fibrous cricothyroid arch
Action
Aids swallowing . Cricopharyngeus acts as upper oesophageal sphincter
Insertion
Cricopharyngeus: continuous with muscle of opposite side, behind pharynx. Thyropharyngeus : lower pharyngeal raphe
Nerve
Pharyngeal plexus (IX, X and sympathetic) via pharyngeal br of X with its motor fibres from cranial accessory (XI)
