Anatomy of Pharynx Flashcards
What is the pharynx?
Essentially a muscular tube
What does the pharynx arise from?
The base of the skull
Where does the pharynx extend down to?
The level of C6
What does the pharynx form?
The upper part of the alimentary canal
What is the pharynx posterior to?
The nasal and oral cavities
Where is the pharynx widest?
Opposite the hyoid bone
Where is the pharynx narrowest?
At its inferior end
What happens to the pharynx at its inferior end?
It becomes continuous with the oesophagus
Where does the posterior wall of the pharynx lie?
Against the prevertebral layer of deep cervical fascia
What is the pharynx divided into?
Three parts/areas;
- Nasopharynx
- Oropharynx
- Laryngopharynx
Where does the nasopharynx lie?
Superior to the soft palate
What is the upper boundary of the nasopharynx?
The base of the skull
What is the relationship between the nasooharynx and the nasal cavities?
It is a posterior extension of the nasal cavities, opening into it through two chonae
What vertebraes lies posteriorly to the nasopharynx?
C1
What structures lie within the nasopharynx?
- Oriface of pharyngotympanic tube
- Collection of lymphoid tissue - the pharyngeal tonsil, or adenoids
Where does the oropharynx extend?
From the level of the soft palate to the superior border of the epiglottis
What vertebrae lie posteriorly to the oropharynx?
C2 and C3
What structures are in the oropharynx?
Palatine tonsils
Where do the palatine tonsils lie?
On either side, in the interval between palatoglossal and palatopharyngeal arches
Where is the laryngopharynx?
Posterior to the larynx
Where does the laryngopharynx extend?
From the epiglottis to oesophagus, at the level of the inferior border of the cricoid cartilage
What vertebral bodies lie posteriorly to the laryngopharynx?
C3-6
What does the laryngopharyngeal cavity have on each side of the laryngeal inlet?
A small depression - the piriform fossa
What do the walls of the larynx consist of externally?
Superior, middle, and inferior constrictors
What innervates the constrictors of the walls of the larynx?
Vagus nerve
What is the function of the constrictor msucles of the larynx?
Relax and contract sequentially from above to propel foood into the oesophagus
What shape are the pharyngeal constrictors?
Circular
What are the names of the constrictor muscles of the pharynx?
- Superior pharyngeal constrictor
- Middle pharyngeal constrictor
- Inferior pharyngeal constrictor
What are the parts of the inferior pharyngeal constrictor?
- Thyropharyngeal
- Cricopharyngeal
What do the walls of the larynx contain internally?
Three intrinsic, longitudinal muscles
What do the intrinsic, longitudinal muscles of the pharynx do?
Elevate the larynx during speaking and swallowing
What are the names of the intrinsic, longitudinal muscles of the pharynx?
- Stylopharyngeus
- Palatopharyngeus
- Salpingopharyngeus
What is the origin of the stylopharyngeus?
Styloid process
What is the attachment of the stylopharyngeus?
Posterior border of thyroid cartilage
What is the stylopharyngeus supplied by?
Glossopharyngeal nerve
What is the origin of the palatopharyngeus?
Hard palate
What is the attachment of the palatopharyngeus?
Posterior border of thyroid cartilage
What is the palatopharyngeus supplied by?
The pharyngeal branch of the vagus
What is the innervation of the palatopharyngeus?
Pharyngeal branch of the vagus
What is the origin of the salpingopharyngeus?
Cartilaginous part of ET
What does the salpingopharyngeus merge with?
Palatopharyngeus
What is the salpinopharyngeus supplied by?
The pharyngeal branch of vagus
What is the majority of the nerve supply to the pharynx derived from?
The pharyngeal plexus of nerves
What is the pharyngeal plexus of nerves formed by?
- Branches of the vagus nerve (and nerves from cranial root accessory that runs with CN X)
- Glossopharyngeal
- Sympathetic branches from the superior cervical ganglion
What do branches of the vagus nerve supply in the pharynx?
All muscles of pharynx, apart from stylopharyngeus and tensor veli palatin
What is tensor veli palatin supplied by?
CN V3
How does the sensory supply of the pharynx differ?
According to different parts of the pharynx
What is the sensory supply of the nasopharynx?
Maxillary nerve
What is the sensory supply to the oropharynx?
Glossopharyngeal nerve
What is the sensory supply to the laryngopharynx?
Vagus nerve
Where is Waldeyer’s Ring formed?
Around the naso- and oro-pharynx
What is Waldeyers Ring?
A continuous lymphoid ring
What is Waldeyer’s Ring formed from?
- (Naso) pharyngeal tonsils
- Palatine tonsils
- Lymphoid nodules on dorsum of tongue
Who are the pharyngeal tonsils prominent in?
Children
What happens to the pharyngeal tonsils in puberty?
They undergo atrophy
What is the result of children having prominent pharyngeal tonsils?
They are more susceptible to adenoid problems
