spotprinter.blogg.se - Inferior pharyngeal constrictor usmle

The pharynx receives sensory innervation from the glossopharyngeal nerve. Sympathetic fibres from the superior cervical ganglion.Branches from the external laryngeal nerve.Pharyngeal branch of the vagus nerve (CN X).Pharyngeal branches from the glossopharyngeal nerve (CN IX).The pharyngeal plexus, which overlies the middle pharyngeal constrictor, is formed by: Motor and sensory innervation of the majority of the pharynx (except nasopharynx) is achieved by the pharyngeal plexus. The pharynx has been split down the midline and opened, to show the longitudinal muscles. In addition to contributing to swallowing, it also opens the Eustachian tube to equalise the pressure in the middle ear.Salpingopharyngeus - originates from the Eustachian tube and inserts onto the pharyngeal wall.Palatopharyngeus - originates from the hard palate of the oral cavity and inserts onto the pharyngeal wall.Unlike the other pharyngeal muscles, it is innervated by the glossopharyngeal nerve (CN IX).Stylopharyngeus - originates from the styloid process of the temporal bone and inserts onto the pharyngeal wall.They act to shorten and widen the pharynx, and elevate the larynx during swallowing. The longitudinal muscles are the stylopharyngeus, palatopharyngeus and salpingopharyngeus. Visible are the circular muscles of the pharynx, and the stylopharyngeus. Fig 4 - Lateral view of the deep structures of the pharynx. Inferior pharyngeal constrictor - located in the laryngopharynx.Middle pharyngeal constrictor - located in the laryngopharynx.Superior pharyngeal constrictor - the uppermost pharyngeal constrictor.They are arranged like stacked glasses, which form an incomplete muscular circle around the pharynx.

There are three circular pharyngeal constrictor muscles - superior, middle, and inferior. The muscles of the pharynx are mostly innervated by the vagus nerve - the only exception being the stylopharyngeus (glossopharyngeal nerve).

All fibres insert posteriorly onto the pharyngeal raphe.

Cricopharyngeal fibres originate from the cricoid cartilage.

Thyropharyngeal fibres originate from the thyroid cartilage.

Inferior pharyngeal constrictor – located in the laryngopharynx.

Inserts posteriorly into the pharyngeal raphe.

Originates from the stylohyoid ligament and the horns of the hyoid bone.

Middle pharyngeal constrictor – located in the laryngopharynx.

Inserts posteriorly onto the pharyngeal tubercle of the occiput and the pharyngeal raphe.

Originates from the pterygomandibular ligament, alveolar process of mandible, medial pterygoid plate and pterygoid hamulus of the sphenoid bone.

Superior pharyngeal constrictor – the uppermost pharyngeal constrictor.

and thus propel the bolus of food inferiorly into the oesophagus. The circular muscles contract sequentially from superior to inferior to constrict the pharyngeal lumen. There are three circular pharyngeal constrictor muscles – superior, middle, and inferior. The muscles of the pharynx are mostly innervated by the vagus nerve – the only exception being the stylopharyngeus (glossopharyngeal nerve). There are two main groups of pharyngeal muscles longitudinal and circular.