Flashcards in 14) The Pharynx Deck (30):
Describe the pharynx:
Muscular tube from base of skull to C6, becomes continuous with oesophagus
What does the posterior wall of the pharynx lie against?
Pre-vertebral layer of deep cervical fascia
Describe the location of the nasopharynx:
Base of skull to upper border of soft palate (C1 to C2)
What is anterior to the nasopharynx?
Nasal cavity, opens into nasopharynx by choanae
What structures are contained in the nasopharynx?
Pharyngeal tonsils (adenoids) and opening of Eustachian tube
What problems can enlarged adenoids cause?
Can block nasal air flow, block ET opening or harbour chronic infection that can transmit to ET or sinuses
Describe the pathogenesis of otitis media (caused by Eustachian tube dysfunction):
Negative pressure in middle ear if ET is blocked, draws transudate from mucosa, allowing an environment for bacteria to proliferate
Describe the location of the oropharynx:
Soft palate to epiglottis (C2 to C3)
What is anterior to the oropharynx?
Describe the position of the palatine tonsils:
Either side, between palatoglossus and palatopharyngeal arches
Describe the location of the laryngopharynx:
Epiglottis to inferior cricoid cartilage (C3 to C6)
What is anterior to the laryngopharynx?
What are the piriform fossa/recesses and what are their function?
Small depression on either side of laryngeal inlet
Allow route for food and fluid to oesophagus that avoids larynx
What are the 3 longitudinal muscles of the pharynx and their innervation?
Stylopharyngeus (CN IX)
Palatopharyngeus (CN X)
Salpingopharyngeus (CN X)
What are the functions of the longitudinal muscles of the pharynx?
Elevate, shorten and widen pharynx during swallowing
Elevate larynx during swallowing
What are the 3 outer circular muscles of the pharynx and their innervation?
Superior, middle and inferior pharyngeal constrictors
What are the two parts of the inferior constrictor muscle?
Thyropharyngeal and cricopharyngeal
What is the function of outer circular muscles?
Constrict walls of pharynx when swallowing (peristalsis)
What is Killian's dehiscence?
Area of weakness between 2 parts of inferior constrictor
When is a pharyngeal pouch likely to form?
Incoordination of pharynx in swallowing so increased pressure in pharynx causing pharyngeal mucosa to herniate through Killian's dehiscence
What are some symptoms of a pharyngeal pouch?
Dysphagia, regurgitation and bad breath
What is the sensory supply to the different parts of the pharynx?
Nasopharynx - maxillary nerve
Oropharynx - glossopharyngeal nerve
Laryngopharynx - vagus nerve
Why is care needed when performing a tonsillectomy?
Profuse bleeding due to rich blood supply
Where are foreign bodies likely to lodge in the pharynx?
Describe the 1st stage of swallowing:
Oral: making bolus and tongue pushing it to oropharynx
Describe the 2nd stage of swallowing:
Soft palate and tongue elevate
Suprahyoid and longitudinal elevate larynx and widen pharynx
Epiglottis closes over larynx
Constrictors transport bolus
Describe the 3rd stage of swallowing:
Oesophageal: Peristalsis by striated muscle and lower smooth muscle
What are some cause of dysphagia?
Progressive neurological disease - Parkinson's/MS
Infection and malignancy
What are some symptoms of difficulty swallowing?
Coughing and choking