Pharynx And Larynx Flashcards
What is the pharynx?
• Musculo-fascial pathway for air and food
• Links oral and nasal cavities with the
esophagus and larynx
• Extends from base of skull to vertebral
level C6/C7
What are the 3 divisions of the pharynx?
Three divisions:
1. Nasopharynx
• Pharyngeal tonsil (adenoids)
• Pharyngotympanic tube
- Oropharynx
• Palatine tonsils
• Valleculae - Laryngopharynx
• Piriform recess (fossa)
What are the circular muscles (constrictors)?
Circular muscles (constrictors) (CN X) - As a group constrict the lumen of the pharynx propelling bolus downward during swallowing
- Superior constrictors
- Middle constrictors
- Inferior constrictors
Joined in the midline at the pharyngeal raphe
Muscles of pharynx
Describe the attachment of the lateral pharyngeal wall
• Lateral attachment of pharyngeal wall is discontinuous and in three parts:
- Medial pterygoid plate and hamulus of sphenoid bone, pterygomandibular raphe, and small part of the mandible
- Lower end of stylohyoid ligament, and hyoid bone
- Oblique line of thyroid cartilage, over cricothyroid, and onto cricoid cartilage
What are the longitudinal muscles?
Longitudinal muscles
- As a group elevates and shortens the pharynx during swallowing
1. Salpingopharyngeus - elevates the pharynx, pulls on auditory tube to equalize pressure in middle ear (pharyngeal branch of CN X)
- Palatopharyngeus - elevates pharynx/larynx (pharyngeal
branch of CN X) - Stylopharyngeus - elevates pharynx/larynx during swallowing (CN IX)
What is the pharyngeal fascia?
Reinforces the wall of the pharynx especially where there is a deficiency in muscles
Two parts:
• Buccopharyngeal fascia – on outer
aspect of muscular wall of pharynx
• Pharyngobasilar fascia – on inner
aspect of the muscular wall of pharynx (deep to mucous lining of the pharynx). Also called pharyngeal aponeurosis
What is the buccopharyngeal fascia?
Buccopharyngeal fascia
covers posterior aspect of the pharyngeal constrictors and esophagus
What is the pharyngeal plexus?
The pharyngeal plexus (CN IX, X) provides motor and sensory innervation to most of the pharynx (excluding nasopharynx)
What is the sensory innervation of the pharynx?
Sensory innervation
• Most of the nasopharynx is innervated by pharyngeal branch of CN V2
- Most of the oropharynx is innervated by CN IX via pharyngeal plexus
* afferent limb of gag reflex
• Most of the laryngopharynx is innervated by CN X via the
IX internal laryngeal n. (branch of superior laryngeal n.)
What is the motor innervation of the pharynx?
Motor innervation
• CN X provides motor innervation to pharynx via pharyngeal branch (except stylopharyngeus m.)
- efferent limb of gag reflex
- CN IX motor innervation to stylopharyngeus m
Summarize muscle pharynx innervation
• All muscles of the tongue
– CN XII – exception palatoglossus – CN X
• All muscles of the palate – CN X
– exception tensor veli palatini – CN V3
• All muscles of the pharynx – CN X
– exception stylopharyngeus – CN IX
• All muscles of the larynx – recurrent laryngeal (CN X)
– exception cricothyroid – external laryngeal (CN X)
What is the blood supply of the pharynx?
External carotid artery
- Ascending pharyngeal artery
- Ascending palatine and tonsillar branches of facial artery
- Numerous smaller branches of maxillary and lingual arteries
Tonsillar a.
Subclavian artery
• Pharyngeal branch of inferior thyroid a.
What is the veinous and lymphatic drainage of the pharynx?
Venous drainage from the pharynx
• pterygoid plexus of infratemporal (IT) fossa facial/retromandibular veins internal jugular v.
Lymphatic drainage - to deep cervical nodes (via retropharyngeal, paratracheal and infrahyoid nodes)
What is the action of tensor vocal cords?
Action: stretches vocal cords by tilting thyroid cartilage forward
Innervation: ext. laryngeal n.
Describe the innervation of the larynx
- above vocal cords – to deep cervical nodes along internal jugular v.
- below vocal cords – to deep nodes associated with inferior thyroid a. or trachea
