The Pharynx Flashcards
What is the pharynx?
A muscular tube
Connects the larynx and oesophagus to the nasal cavities
What can pass down the pharynx?
Air and food
Where, precisely, does the pharynx begin and end?
at the end it
Begins at the base of the skull
Ends inferior to the cricoid cartilage (C6)
become continuous with the esophagus
Name the three parts of the pharynx
Nasopharynx
Oropharynx
Laryngopharynx
What are the muscles of the pharynx innervated by?
The vagus nerve (CN X)
Except for the stylopharyngeus, innervated by the glossopharyngeal nerve (CN IX)
What is the function of the circular muscles of the pharynx?
Contract sequentially from superior to inferior to constrict the lumen and propel bolus of food inferiorly into the oesophagus.
Structure of the circular muscles of the pharynx?
Stacked like glasses
Form an incomplete muscular circle
Name the circular muscles of the pharynx and the parts in which they are found.
Superior pharyngeal constrictor - oropharynx
Middle pharyngeal constrictor - laryngopharynx
Inferior pharyngeal constrictor - laryngopharynx
What are the two components of the inferior pharyngeal constrictor
Superior (thyropharyngeus) - has oblique fibres that attach to the thyroid cartilage
Inferior (cricopharyngeus) - horizontal fibres attaching to the cricoid cartilage
Generally, what is the structure of the wall of the pharynx?
Pharyngeal mucosa
Incomplete ring of lymphoid tissue
Longitudinal muscular layer
Circular muscular layer
Buccopharyngeal fascia
Function of the longitudinal muscles of the pharynx?
Shorten and widen the pharynx
Elevate it during swallowing
Attachements of the longitudinal muscles of the pharynx?
Stylopharyngeus - styloid process of temporal bone to the pharynx
Palatopharyngeus - hard palate of oral cavity to the pharynx
Salpingopharyngeus - Eustachian tube to pharynx
What extra function does the salpingopharyngeus perform?
Opens the Eustachian tube to equalise pressure in the middle ear with the atmosphere.
Sensory innervation of the pharynx?
Nasopharynx - maxillary
Oropharynx - glossopharyngeal
Laryngopharynx - vagus
Sympathetic innervation to the pharynx?
From the superior cervical ganglion
Arterial supply to the pharynx?
Branches of the external carotid
- ascending pharyngeal
- lingual
- facial
- maxillary
Venous drainage of the pharynx?
Pharyngeal venous plexus, drains into the internal jugular
Where does the nasopharynx run between?
Base of the skull to the soft palate
Function of the nasopharynx?
Extension of the nasal cavity
Conditions inspired air and propogates it into the larynx
Epithelium of the nasopharynx?
Ciliated pseudostratified columnar with goblet cells