QS Study

Intrinsic Muscles of the Pharynx

The pharynx is a wide muscular tube situated behind the nose, the mouth and the larynx. It is a part of the upper respiratory tract. It is a five-inch-long tube that starts near our nose and ends at our windpipe. It receives food and air from the mouth, and air from the nasal cavities.

It is a muscular tube that connects the oral and nasal cavity to the larynx and oesophagus.

Intrinsic Muscles of the Pharynx 1

Fig: Intrinsic Muscles of the Pharynx

The intrinsic muscles of the pharynx are –

(1) Cricopharyngeus – The circular muscles contract sequentially from superior to inferior to constrict the lumen and propel the bolus of food inferiorly into the oesophagus.

  • Origins: stylohyoid ligament, greater and lesser cornu of the hyoid bone
  • Insertions: pharyngeal raphe
  • Actions: constrict the middle portion of the pharynx

(2) Stylopharyngeus – arises from the styloid process of the temporal bone, inserts into the pharynx.

  • Origins: medial aspect of the base of the styloid process
  • Insertions: the posterolateral border of the thyroid cartilage
  • Actions: elevates the pharynx and expands it laterally

(3) Salpingopharyngeus – arises from the Eustachian tube, inserts into the pharynx.

  • Origins: cartilage of the auditory tube
  • Insertions: upper border of thyroid cartilage and inferior constrictor muscle fibers
  • Actions: elevates the superior and lateral aspects of the pharynx

(4) Palatopharyngeus – arises from the hard palate of the oral cavity, inserts into the pharynx.

  • Origins: posterior border of the hard palate on the palatine aponeurosis
  • Insertions: posterior aspect of the lamina of the thyroid cartilage of the larynx
  • Actions: elevates the pharynx.
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