Soft Palate & Pharynx

Soft Palate

  • Moveable partition between the oropharynx + nasopharynx

  • made of muscle covered by non-keratinised squamous epithelium

  • Extends laterally to form the palatoglossal + palatopharyngeal arches

  • receives sensory innervation via the maxillary division of trigeminal nerve

Muscles

Levator veli palatini

  • O- auditory tubes & petrous part of the temporal bone

  • Ins- palatine aponeurosis

  • A- elavates soft palate & equalises pressure in the middle ear

  • Inn- Vagus (pharyngeal plexus)

Tensor veli palatini

  • O- auditory tubes & sphenoid bone

  • Ins- palatine aponeurosis

  • A- tenses soft palate & equalises pressure in middle ear

  • Inn- Mandibular division of trigeminal

Palatoglossus

  • O- palatine aponeurosis

  • Ins- posterolateral aspect of the tongue

  • A- elevates the tongue and narrows the oropharyngeal isthmus

  • Inn- vagus (pharyngeal plexus)

Palatopharyngeus

  • O- palatine aponeurosis

  • Ins- lateral phayngeal wall

  • A- elevates the pharynx

  • Inn- vagus (pharyngeal plexus)

Functions of the soft palate

  • seals off the nasopharunx in swallowing and speech

  • narrows orophayngeal isthmus

  • elevates tongue

  • assists in elevationof pharunx during swallowing

Pharynx

  • Afibromuscular tube that extends from the base of the skull to the oesophagus

Functions

  • passageway for food and air

  • Important roles in swallowing

  • Articulation

Anterior openings for nose, mouth and larynx

Divisions- Nasopharynx, oropharynx & laryngopharynx

Nasopharynx

  • Extends from base of skull to tip of uvula

  • Lined by pseudostratified ciliated columnar epithelium with goblet cells

  • Important features- ostium of the eustachian tube, pharyngeal tonsils, tubal tonsils

  • sensory innervation: maxillary division of the trigeminal & glossopharyngeal

Orpharynx

  • extends from uvula to tip of epiglottis

  • lined by non- keratinised stratified squamous epithelium

  • Oropharyngeal isthmus in anterior wall contains- palatoglossal folds, palatopharyngeal folds, tonsillar recess and palatine tonsils

  • Posterior 1/3 of tongue runs vertically in the anterior wall- lingual tonsils

  • mucosa of tongue reflected onto epiglottis to form the valleculae and the medial and lateral glossoepiglottic folds

  • sensory innervation: plossopharyngeal nerve

Laryngopharynx

  • extends from the epiglottis to the oesophagus

  • laryngeal inlet located anteriorly- bounded by the arepiglottic folds and the epiglottis

  • piriform recess lateral to laryngeal inlet

  • lined by non-keratinised stratified squamous epithelium

  • sensory innervation: plossopharyngeal & vagus nerve

Waldeyer’s ring

A ring of lymphoid tissue that guards the entrance of the respiratory & gastointestinal systems

Muscles

constrictor- contract sequentially to push bolus of food into oesophagus: innervated by pharyngeal plexus (vagus)

Superior constrictor

  • O- Sphenoid bone, mandible & pterygomandibular raphe

  • Ins- Pharyngeal tubercle & pharyngeal raphe

Middle constrictor

  • O- hyoid bone & stylohyoid ligament

  • Ins- pharungeal raphe

Inferior constrictor

  • thyropharyngeaue part

  • O- thyroid cartilage

  • Cricopharyngeus part

  • O- cricoid cartilage

  • Ins- Pharyngeal raphe

Longitudinal- shroten and widen the pharynx, elevate the pharynx & larynx, open the auditory tube

Salpingopharyngeus

  • O- auditory tube

  • Ins- Lateral pharyngeal wall

  • Inn- Pharyngeal plexus (vagus)

Stylopharyngeus

  • O- styloid process of the temporal bone

  • Ins- Posterior aspect of the thyroid cartilage & lateral pharyngeal wall

  • Inn- Glossopharyngeal nerve

Palatopharyngeus

  • O- palatine aponeurosis

  • Ins- posterior aspect of the thyroid cartilage & lateral pharyngeal wall

  • Inn- pharyngeal plexus

Pharyngeal plexus

  • located on the outer wall of the constrictor muscles

  • Consists of

    • sensory fibres from glossopharyngeal nerve

    • motor fibres from vagus nerve

    • sympathetic fibres (vasomotor)

CN IX- Glossopharyngeal nerve

  • Arises in the medulla oblongata

  • Exists the skull at the jugular foramen

  • Functions

    • general sensation- pharynx, post 1/3 tongue & ear

    • taste sensation from pst 1/3 tongue & pharynx

    • visceral sensation from carotid body & sinus

    • parasympathetic to parotid gland

    • motor to stylopharyngeus muscle

CN X- Vagus Nerve

  • Arises in the medulla oblongata

  • exits the skull at the jugular foramen

  • Functions

    • General sensation- pharynx, larynx & oesophagus

    • motor to muscles of larynx, pharynx & palate

    • Parasympathetic to viscera of chest & abdomen

    • visceral sensory to aortic bodies & sinus, abdominal & thoracic viscera