Pharynx and Cervical Oesophagus Flashcards
What is the Pharynx?
- Superior expanded part of the oesophagus posterior to the nasal and oral cavities
Pharynx
* Extent:
o Superior-
o Inferior-
o Anterior-
o Posterior-
o Superior- cranial base
o Inferior- inferior border of cricoid cartilage at the level of C6 vertebra
o Anterior- nasal cavity, oral cavity and larynx
o Posterior- buccopharyngeal fascia
Pharynx:
* Widest opposite hyoid (5 cm) and narrowest at junction with oesophagus (1.5 cm)
* flat posterior wall lies against the prevertebral layer of deep cervical fascia
* divided into 3 parts:
o Nasopharynx- posterior to the nose and superior to the soft palate
o Oropharynx- posterior to mouth
o Laryngopharynx- posterior to the larynx
What is the Nasopharynx? (2)
- Has a respiratory function
- Posterior extension of the nasal cavities
Nasopharynx:
- Borders:
o Anterior-
o Posterior-
o Roof-
o Anterior- choana and soft palate
o Posterior- basilar part of the occipital bone and C1 vertebra
o Roof- body of sphenoid
Nasopharynx:
o Tonsils (aggregates of lymphoid tissue): (2)
- Pharyngeal (adenoid) tonsil- in the mucosa of the roof and posterior wall of the nasopharynx
- Tubal tonsils- in the submucosa of the pharynx near the nasopharyngeal opening
Nasopharynx:
o Opening of the _________ tube
pharyngotympanic
Nasopharynx:
o Salpingopharyngeal fold: (3)
- Extends inferiorly from the medial end of the pharyngotympanic tube
- Vertical fold of the mucosa
- Covers the salpingopharyngeus muscle
Nasopharynx:
o Torus tubarius:
- Superior to the opening of the pharyngotympanic tube
Nasopharynx:
o Pharyngeal recess: (2)
- Posterior to the torus tubarius and salpingopharyngeal fold
- Extends laterally and posteriorly
What is the function of the Oropharynx?
- Has a digestive function
Oropharynx:
Boundaries:
o Superior-
o Inferior-
o Lateral-
o Posterior-
o Superior- soft palate and uvula
o Inferior- base of the tongue and superior border of epiglottis
o Lateral- palatopharyngeal and palatoglossal arches
o Posterior- pharyngobasilar fascia over palatopharyngeus, superior constrictor and body of C2
Oropharynx:
Contents: (3)
o Palatine tonsils
- On each side of the oropharynx in the tonsillar bed between the palatine arches
(palatopharyngeal and palatoglossal arches)
o Tonsillar bed
- Formed by the superior pharyngeal constrictor and the thin, fibrous sheet of pharyngobasilarnfascia
* Fascia blends with the periosteum of the cranial base
o Lingual tonsils
- On the posterior third of the tongue
What does Pharyngeal lymphatic (Waldeyer’s) ring consist of? (5)
1 pharyngeal tonsil
2 tubal tonsils
2 palatine tonsils
1 lingual tonsil
2 lateral bands
Where does the Laryngopharynx lie?
- Lies posterior to the larynx
Laryngopharynx
* Boundaries:
o Superior-
o Inferior-
o Anterior-
o Posterior-
o Lateral-
o Superior- superior border of the epiglottis and pharyngoepiglottic folds
o Inferior- inferior border of the cricoid cartilage
o Anterior- larynx
o Posterior- pharyngobasilar fascia, middle and inferior constrictor muscles and C4- C6 vertebrae
o Lateral- pharyngobasilar fascia and middle and inferior constrictor muscles
Laryngopharynx:
Features: (3)
o Laryngeal inlet
o Piriform fossa (recess)
o Aryepiglottic fold
Laryngopharynx:
o Laryngeal inlet:
- Communication between the laryngopharynx and the larynx on the anterior wall
Laryngopharynx:
o Piriform fossa (recess): (3)
- Small depression of the laryngopharyngeal cavity on either side of the laryngeal inlet
- Laterally bounded by the medial surfaces of the thyroid cartilage and the thyroid membrane
- Branches of the internal and recurrent laryngeal nerves lie deep to its mucosa
- Vulnerable to injury when a foreign body lodges in the fossa
Laryngopharynx:
o Aryepiglottic fold:
- Separates the piriform fossa from the laryngeal inlet
What are the features of the Pharyngeal muscles? (3)
- Arranged with longitudinal muscles internally and circular muscles externally
- Circular muscles are the pharyngeal constrictors
- Internal longitudinal muscles elevate the larynx and shorten the pharynx during swallowing/speaking
Pharyngeal muscles:
* Fascial lining: (2)
o Strong internal pharyngobasilar fascia
o Thin external buccopharyngeal fascia (blends with the pretracheal layer of deep cervical fascia)
* Constrictors contract involuntarily for sequential contraction
What are the External layer- pharyngeal constrictors?
Pharyngeal constrictors:
Superior:
Origin:
Insertion:
Innervation:
Main Action:
- Pterygoid hamulus
- Pterygomandibular raphe
- Adjacent part of mandible
Pharyngeal tubercle on basilar part of occipital bone
- Pharyngeal br. of vagus n.
- pharyngeal plexus
Constrict walls of pharynx during swallowing
Pharyngeal constrictors:
Middle
Origin:
Insertion:
Innervation:
Main Action:
- stylohyoid ligament
- greater and lesser horns of hyoid
Pharyngeal raphe
- Pharyngeal br. of vagus n.
- pharyngeal plexus
- br. of external and recurrent laryngeal nn. of vagus n.
Constrict walls of pharynx during swallowing
Pharyngeal constrictors:
Inferior
Origin:
Insertion:
Innervation:
Main Action:
- Oblique line of thyroid cartilage
- Side of cricoid cartilage
Pharyngeal raphe
- Pharyngeal br. of vagus n.
- pharyngeal plexus
- br. of external and recurrent laryngeal nn. of vagus n.
Constrict walls of pharynx during swallowing
What are the Internal layer- longitudinal muscles? (3)
Internal layer- longitudinal muscles
Palatopharyngeus
Innervation:
Main Action:
- Pharyngeal br. of vagus n.
- pharyngeal plexus
Elevate (shorten and widen) pharynx and larynx during swallowing and speaking
Internal layer- longitudinal muscles
Salpingopharyngeus
Innervation:
Main Action:
- Pharyngeal br. of vagus n.
- pharyngeal plexus
Elevate (shorten and widen) pharynx and larynx during swallowing and speaking
Internal layer- longitudinal muscles
Stylopharyngeus
Innervation:
Main Action:
- Glossopharyngeal n.
Elevate (shorten and widen) pharynx and larynx during swallowing and speaking
Gaps in the pharyngeal constrictor muscles:
1. Between superior pharyngeal constrictor and cranium
Contents: (3)
- Levator veli palatini
- Pharyngotympanic tube
- Ascending palatine artery
Gaps in the pharyngeal constrictor muscles:
2. Between superior and middle pharyngeal constrictors
Contents: (3)
- Stylopharyngeus
- Glossopharyngeal nerve (CN IX)
- Stylohyoid ligament
Gaps in the pharyngeal constrictor muscles:
3. Between middle and inferior pharyngeal constrictors
Contents: (2)
- Internal laryngeal nerve
- Superior laryngeal artery and vein
Gaps in the pharyngeal constrictor muscles:
4. Inferior to the inferior pharyngeal constrictor
Contents: (2)
- Recurrent laryngeal nerve
- Inferior laryngeal artery and vein
Gaps in the pharyngeal constrictor muscles:
4. Inferior to the inferior pharyngeal constrictor
Contents: (2)
- Recurrent laryngeal nerve
- Inferior laryngeal artery and vein
What are the arteries of the pharynx? (4)
- tonsillar branch of facial a.
- Ascending & descending palatine a.
- From external carotid a.
- Inferior thyroid a. from subclavian a.
What are the arteries that extend from the external carotid a.? (3)
o Lingual a.
o Superior thyroid a.
o Ascending pharyngeal a.
What are the veins of the pharynx?
- Inferior part:
o External palatine v. to pharyngeal
venous plexus to pterygoid venous
plexus
o Thyroid vv. to IJV
Nerves of the pharynx
* Derives from pharyngeal nerve _______
Nerves of the pharynx
* Motor fibres: (3)
o From vagus n. to all muscles of
pharynx and soft palate except
tensor veli palatini and stylopharyngeus
o From glossopharyngeal n. to stylopharyngeus
o From mandibular n. to tensor veli palatini
Nerves of the pharynx
* Sympathetic vasomotor fibres:
o From superior cervical ganglion to blood vessels
Nerves of the pharynx
* Sensory fibres:
o From glossopharyngeal n. to all parts of the pharynx
o From maxillary nerve to mucosa of anterior and superior nasopharynx
What is the Cervical Oesophagus?
- Muscular tube connecting the pharynx to the stomach
Where does the Cervical Oesophagus begin? (2)
- Begins at the pharyngo-oesophageal junction
o Narrowest part of the oesophagus
o Cricopharyngeal part of the inferior pharyngeal constrictor acts as a sphincter
- First third is ______, middle is mixed, last third is _______.
voluntary
involuntary
Cervical Oesophagus:
- Cervical oesophagus- part of the voluntary upper third
o Begins immediately posterior to the inferior border of the ______ cartilage - Level of ___ vertebra
o Inclines slightly to the left as it descends into the superior ________ - Enters through superior _____ aperture and becomes thoracic oesophagus
cricoid
C6
mediastinum
thoracic
Cervical Oesophagus:
* Slit-like ____ when empty
* Lumen expands for food bolus which elicits reflex _____ in the inferior two thirds
lumen
peristalsis
Cervical Oesophagus:
* Anterior relations: (2)
o Trachea (attached by loose connective tissue)
o Recurrent laryngeal nerves (in tracheo-oesophageal groove)
Cervical Oesophagus:
* Posterior relations:
- Posterior- cervical vertebrae
Cervical Oesophagus:
* Lateral relations: (3)
o Right and left lobes of thyroid gland
o Carotid sheath and its contents
o Thoracic duct on the left
Cervical Oesophagus:
* Inferior relations: (2)
o Cervical pleura at the root
o Thoracic duct
Cervical Oesophagus:
Arteries:
- Branches of the inferior thyroid aa.
o Gives off ascending and descending branches that anastomose and cross the midline
Cervical Oesophagus:
Veins:
- Inferior thyroid vv.
Cervical Oesophagus:
Nerves: (3)
- Somatic motor and sensory to upper half and autonomic and visceral sensory to lower half
- somatic fibres via branches from the recurrent laryngeal nerves
- vasomotor fibres from the cervical sympathetic trunks via the plexus around the inferior thyroid artery
