The Pharynx Flashcards
The roof of the nasopharynx is formed by?
Base of the skull (underside of sphenoid & basal part of occipital bone)
In relation to the larynx, the (laryngo) pharynx lies where?
Posterior
During swallowing the bolus of food/ drink is directed to the oropharynx and then the oesophagus.
What prevents this bolus from entering into the nasopharynx?
The Soft Palate - Uvula
What prevents a food bolus from entering the larynx?
The Epiglottis
What are the three layers of the pharynx?
Outer circular layer:
Middle fibrous layer
Inner mucous membrane
What is the outer muscles layer made up of?
Formed by the three constrictor (superior, middle and inferior constrictor) muscles.
These muscles are arranged like flower pots placed one inside the other, but are open in front at the entries of the nasal, buccal and laryngeal cavities.
What is the inner longituinal layer?
Stylopharyngeus
Salpingopharyngeus
Palatopharyngeus
What is the middle fibrous layer?
Merges with the deep fascia of the muscles and fills in gaps between muscles.
What does the pharynx recieve?
Innervation from the pharyngeal plexus
Branches of which 2 cranial nerves form the pharyngeal plexus?
Vagus n. (Cr. N. X) & Glossopharyngeal n. (Cr. N. IX)
Of these which nerve is sensory to the pharynx?
Glossopharyngeal nerve
Which nerve provides most of the motor innervation?
Vagus nerve
What is the role played by the constrictor muscles of the pharynx during swallowing?
Constrict the walls of the pharynx during swallowing. – propel bolus down
What is the role played by the longitudinal layer of muscles during swallowing?
Elevate (shorten & widen) the pharynx during swallowing.
What is the role played by tongue and palate muscles during swallowing?
A trough is formed by the back of the tongue – this obliterates against the hard palatefrom front to back, forcing the bolus to the back of the tongue.
What is the pharyngeal lymphoid ring a collelction of?
Lymphoid tissue that protects the entrance to the oropharynx
What is the purpose of having such a lymphoid ring in this location?
First line of defence against infection of things entering through the nasopharynx or oropharynx
Name the lymphoid collections present in Waldeyers Ring:
2x Tubal tonsils
2x Palatine tonsils
- Pharyngeal Tonsil*
- Lingual Tonsil*
What can repeated infection of the lymphoid collections neccisate?
Surgical removal
