Anatomy of Pharynx Flashcards
What is the pharynx?
Muscular tube connecting nasal cavity, larynx, oesophagus
At what level of cervical vertebrae does the pharynx end?
C6
Name the 3 compartments of the pharynx
Nasopharynx
Oropharynx
Laryngopharynx
List the 3 functions of the pharynx
1- To pass food across the airway safely in swallowing
2- Directs air flow via oral cavity for maximum air flow
3- Closes the upper airway from the oral cavity in chewing and swallowing
What are the 3 openings of the larynx?
Nasal cavity
Oral cavity
Opening of larynx
Where does the pharynx attach at the top?
Basioccipital bone
What does the pharynx have anterior attachments to?
Occipital bone
Sphenoid
Mandibular body
Hyoid, thyroid and cricoid cartilages
What is a raphe?
Ridge/seam in an organ or tissue with marks where two lines fuse in the embryo
What are the 3 functions of the muscles of the pharynx?
1- Assists movements of the soft palate
2- Constricts the pharynx to move boli of food along
3- Lifts pharynx as a whole
What are the 2 types of muscles of the pharynx?
Circular
Longitudinal
How many circular muscles are there?
3
Name the 3 circular pharynx muscles
Superior pharyngeal constrictor
Middle pharyngeal constrictor
Inferior pharyngeal constrictor
Name the 3 longitudinal pharynx muscles
Stylopharyngeus
Palatopharyngeus
Salpingopharyngeus
Where in the pharynx is superior pharyngeal constrictor found?
Oropharynx
Where in the pharynx is the middle pharyngeal constrictor found?
Laryngopharynx
Where in the pharynx is the inferior pharyngeal constrictor found?
Laryngopharynx
What are all the circular pharyngeal muscles innervated by?
Vagus nerve
What are all the circular pharyngeal muscles innervated by?
Vagus nerve
How many longitudinal pharyngeal muscles are there?
3
What is the main function of the circular pharyngeal muscles?
To constrict lumen to propel food into the oesophagus
What is the main function of the longitudinal muscles of the pharynx?
To widen and shorten the pharynx, elevates larynx in swallowing
What nerve innervates the stylopharyngeus?
Glossopharyngeal nerve
What nerve innervates palatopharyngeus?
Vagus nerve
What nerve innervates salpingopharyngeus?
Vagus nerve
Name 5 muscles that are classed as muscles of the soft palate?
Tensor veli palatini
Levator veli palatini
Palatoglossus
Palatopharyngeus
Superior pharyngeal constrictor
What nerve innervates tensor veli palatini?
Mandibular division of trigeminal
What nerve innervates levator veli palatini?
Vagus nerve
What nerve innervates palatoglossus?
Vagus nerve
What is the function of tensor veli palatini?
Tenses the soft palate so it is tight
What is the function of levator veli palatini?
Elevates the soft palate
What is the function of palatoglossus?
Lowers the soft palate
What is the function of the superior constrictor of pharynx?
Lifts and closes the sphincter of soft palate
What is the function of palatopharyngeus?
Lowers posterior side of palatopharyngeus
Why would you want to close the sphincter of the soft palate?
To close off the nasopharynx from the oropharynx
Where are the pharyngeal tonsils found?
In the folds of the pharyngeal arch
What nerves make up the pharyngeal plexus?
Pharyngeal branch of vagus nerve
Glossopharyngeal nerve
Sympathetic fibres from superior cervical ganglion
What nerves make up the motor supply to the pharynx?
Vagus nerve
Accessory nerve
Glossopharyngeal
What nerve gives sensory innervation to the nasopharynx?
Maxillary nerve of trigeminal
What nerve gives sensory innervation to the oropharynx?
Glossopharyngeal nerve (gag reflex)
What nerve gives sensory innervation to the laryngopharynx?
Sensory laryngeal nerve of the vagus nerve
What is the main artery supplies the pharynx?
External carotid artery
List the 4 branches of the external carotid artery that supplies the pharynx?
Ascending pharyngeal
Lingual
Facial
Maxillary
How does venous blood drain from the pharynx?
Drains through the pharyngeal venous plexus, which drains into internal jugular vein
How does venous blood drain from the pharynx?
Drains through the pharyngeal venous plexus, which drains into internal jugular vein
What are the 4 tonsils of the pharynx?
Adenoids
Tubar tonsils
Palatine tonsils
Lingual tonsils
What are tonsils?
Collection of lymphoid tissues, covered by mucous membrane. Found at the junction between the oral cavity->pharynx and nasal cavity->pharynx
What cartilage is found on the anterior of the thyroid cartilage?
Epiglottis
Cricoid cartilage
What cartilage is found on the anterior of the thyroid cartilage?
Epiglottis
Cricoid cartilage
What is the function of the nasopharynx?
Respiratory function, conditions inspired air and propogates it to the larynx
What are the types of cells found on the nasopharynx?
Ciliated pseudo-stratified columnar epithelium with goblet cells
What are the types of cells found on the nasopharynx?
Ciliated pseudo-stratified columnar epithelium with goblet cells
What tonsils are found in the nasopharynx?
Adenoid tonsils
In which section of the pharynx is the the auditory tube opening?
Nasopharynx
What does the auditory tube connect?
The anterior wall of the tympanic cavity too the nasopharynx
What is the composition of the auditory tube?
Anterior 2 thirds is cartilaginous
Posterior third is bony
Which tonsils are in close proximity to the opening of the auditory tube to the nasopharynx?
Tubar tonsils
Name the muscle of the soft palate that helps to close the auditory tube
Tensor tympani
What nerves give innervation to tensor tympani?
Vagus nerve
Madibular division of trigeminal
What is the purpose of the auditory tube?
Exchanges pressure between the ear and the mouth
What is the purpose of the auditory tube?
Exchanges pressure between the ear and the mouth
How does the opening and closing of the auditory tube allow the equalising of pressure?
Mouth movements can move the mucosa to open the tube, allowing air pressure to equalise in the ear
Why does the auditory tube have to be flexible?
Because the tube also grows as you grow into an adult
Why does the auditory tube have to be flexible?
Because the tube also grows as you grow into an adult
Why are middle ear infections more common in children?
The auditory tube is a lot shorter in children than in adults
What are the piriform fossae?
Depression of the mucous membrane on each side of the laryngeal inlet
What is the function of the piriform fossae and the valleculae of the tounge?
They channel food and water around the laryngeal inlet to prevent choking
Where are the valleculae of the tongue found in relation to the pharynx?
Anterior to the pharynx
Why do adenoid tonsils enlarge?
Can enlarge due to viral infections of the upper respiratory tract
How do enlarged adenoid tonsils obstruct pressure equalisation?
They can obstruct the opening of the Eustachian tube, thereby preventing pressure equalisation
How do enlarged adenoid tonsils obstruct pressure equalisation?
They can obstruct the opening of the Eustachian tube, thereby preventing pressure equalisation
Name the disease that can occur from the blockage of the Eustachian tube
Chronic otitis media (with effusion, fluids cannot drain - glue ear)
What is found in the oropharynx?
The posterior third of the tongue
What is found in the oropharynx?
The posterior third of the tongue
Where are the lingual tonsils located in the oropharynx?
Inferiorly to the tongue
Where are the palatine tonsils located in the oropharynx?
In tonsillar fossa between palatoglossal and palatopharyngeal arches of oral cavity
Which muscle of the pharynx is most associated with phases of swallowing?
Superior constrictor muscle of pharynx
What is tonsillitis?
Red, enlarged palatine tonsils and jugulo-digastric lymph nodes
How is chronic infection of palatine tonsils treated?
Tonsillectomy
What are the main arteries that would bleed in a tonsillectomy?
External palatine vein
Tonsillar branch of facial artery
What happens if tonsillitis spreads to the peritonsillar tissue?
Can cause an abscess to form, which can lead to deviation of the uvula (quinsy)
How is enlargement of palatine tonsils treated?
Draining the abscess and antibiotics
What 2 parts can the inferior pharyngeal constrictor be divided into?
Thyropharyngeus
Cricopharyngeus
What is the action of the inferior pharyngeal constrictor in swallowing?
Thyropharyngeus contracts, cricopharynxgeus relaxes
Bolus of food can then be propelled into oesphagus to prevent the intrapharyngeal pressure form increasing
What happens if the relaxation and contraction of the inferior pharyngeal constrictor cannot occur?
Pharyngeal mucosa forms a midline diverticulum between the thyropharyngeus and cricopharyngeus, where food can accumulate -> dysphagia
What happens if the relaxation and contraction of the inferior pharyngeal constrictor cannot occur?
Pharyngeal mucosa forms a midline diverticulum between the thyropharyngeus and cricopharyngeus, where food can accumulate -> dysphagia
What are the 4 main stages of swallowing?
1- Trap the bolus in the anterior part of oral cavity
2- Move bolus from mouth to entrance of pharynx
3- Allow bolus to enter oesophagus whilst closing the entrance to the larynx and nasal cavity
4- transport bolus through oesophagus to the stomach
What happens to breathing during swallowing?
There is a brief interruption of breathing
Outline the oral preparatory phase of swallowing
1- Lips are closed (uses muscles of facial expression)
2- Food is squeezed from oral vestibule between teeth (lips and buccinator)
3- Oral cavity sealed posteriorly by depressing soft palate against back of the tongue
Outline the oral phase of swallowing
1- Tongue is raised against hard palate to push the bolus backward
2- Mandible is elevated and hyoid bone is raised (prevents food entering the larynx)
3- Soft palate elevated to close off nasopharynx and direct bolus to oropharynx
What triggers the pharyngeal phase of swallowing?
Food bolus touching the back of the oropharynx
Outline the pharyngeal phase of swallowing
1- Sequential contraction of pharyngeal constrictors
2- Bolus contacts epiglottis, folds it back over the laryngeal inlet
3- Respiration stops
4- Vestibular and vocal folds are adducted strongly (prevent food entering)
Outline the oesophageal phase of swallowing
1- Cricopharyngeus contracts to initiate passage of bolus through oesphagus
2- Vagal nuclei conducts a wave of contraction of circular muscles down the oesphagus
How is the larynx protected during swallowing?
It is lifted away, and closed by epiglottis
Valleculae of tongue guide food away from it
In what situation would an elderly person have to relearn the swallowing reflex?
If they suffer a stroke and lose proprioception and coordination
