Pharynx Flashcards
Where is the pharynx found?
Posterior to the nasal cavity, oral cavity and the larynx
What are the divisions of the pharynx?
Nasopharynx
Oropharynx
Laryngopharynx
Where does the nasopharynx run?
From the posterior border of the nasal septum to the soft palate
What lines the nasopharynx?
Respiratory epithelium
(Ciliated columnar cells)
What are the boundaries of the oropharynx?
Soft palate
Base of tongue
Superior border of epiglottis
What lines the oropharynx?
Same epithelium as oral cavity - stratified squamous
What are the borders of the laryngopharynx?
Superior border of epiglottis
Inferior border of cricoid cartilage
Continuous with the oesophagus
What are tonsils?
Lymphoid tissue found in several places forming a tonsillar ring (Waldeyer’s)
Protects the airways
What are the different tonsils?
Pharyngeal tonsils
Tubal tonsils
Palatine tonsils
Lingual tonsils
What is the purpose of the still pharyngobasilar fascia?
Holds the nasopharynx open
What are the 3 pharyngeal constrictors and what do they do?
Superior, middle and inferior
Push the food bolus towards the oesophagus
What do the pharyngeal elevators do?
Lift the pharynx to receive the food bolus from the oral cavity
What supplies the pharyngeal constrictors?
The vagus nerve (CNX) via the pharyngeal plexus
Describe the lower circular part of the inferior pharyngeal constrictor
Known as cricopharyngeas
Forms a sphincter around the upper oesophagus preventing air being drawn into the stomach during inhalation
What are the pharyngeal elevators?
Palatopharyngeus
Stylopharyngeus
Salpingopharyngeus
Where are the pharyngeal elevators found?
Descend from the skull to fan out into the inner surface of the pharynx
Some may also send fibres to the thyroid cartilage ensuring simultaneous elevation of the pharynx and larynx during swallowing
What is the action of the palatopharyngeus?
Elevates the pharynx and larynx
Draws the soft palate downwards
What innervates the palatopharyngeus?
Vagus nerve
What is the function of the stylopharyngeus?
Elevates the pharynx and larynx
What innervates the stylopharyngeus?
Glossopharyngeal nerve
Where does the salpingopharyngeus originate?
The auditory tube
What is the action of the salpingopharyngeus?
Elevates the pharynx and larynx
Helps open the auditory tube during swallowing for pressure equalisation in the middle ear
What innervates the salpingopharyngeus?
Vagus nerve
What are the phases of swallowing?
Oral phase
Pharyngeal phase
Oesophageal phase
Describe the oral phase of swallowing
Voluntary phase
Bolus formed in oral cavity by chewing and tongue movements
Bolus is pushed into the oropharynx by the tongue
Describe the pharyngeal phase of swallowing
Involuntary phase
Superior pharyngeal constrictor contraction and soft palate elevation
Pharyngeal elevation to receive bolus (pharyngeal elevators)
Bolus pushed towards the oesophagus (pharyngeal constrictors)
Epiglottis closes the laryngeal inlet protecting the airway
Describe the oesophageal phase of swallowing
As the inferior pharyngeal constrictor contracts the upper oesophageal sphincter relaxes allowing the bolus into the oesophagus
Peristaltic movements move the bolus towards the stomach
