Pharynx and Pre-Vertebral Region Flashcards
Where does the pharynx extend from, and to
The cranial base to the inferior border of the C6 vertebrae posteriorly
Describe the inner lining of the pharynx
Superiorly = ciliated columnar epithelium Inferiorly = stratified squamous epithelium
Name the 3 regions of the pharynx
- Nasopharynx (posterior to nasal cavities)
- Oropharynx (posterior to the mouth)
- Laryngopharynx (posterior to the larynx, and blends with the oesophagus)
Describe the muscular layers underneath the fibrous layer
- Circular constrictor muscles
2. Longitudinal muscles
What tube exists in the lateral wall of the nasopharynx, and describe its function
Auditory tube = communicates with the middles air, equalising pressure either side of the tympanic membrane
Describe the borders of the nasopharynx
Roof = sphenoid, occipital, and pharyngeal tonsil Floor = soft palate Anterior = nasal passages Posterior = roof and C1 level Lateral = auditory tube
What are the tonsils
Aggregations of lymphoid tissue
Describe the borders of the oropharynx
Roof = soft palate Floor = posterior 1/3rd tongue, lingual tonsil, and glossoepiglottic folds Anterior = mouth Posterior = C2/3 level Lateral = palatoglossal and palatopharyngeal folds (arches) with palatine tonsils
Where are the palatine tonsils located
Either side of the oropharynx in the interval between the palatine arches
Describe the borders of the laryngopharynx
Anterior = larynx Posterior = C3-6 vertebrae Lateral = supported by thyroid cartilage, aryepiglottic fold, and thyrohyoid membrane
Name the 3 pharyngeal constrictor muscles
- Superior
- Middle
- Inferior
Describe the arrangement of each pharyngeal constrictor muscle
Right and left parts meet in the posterior midline to form a fibrous raphe
Describe the innervation to the pharyngeal muscles
All (except the stylopharyngeus) vagus nerve (CN X) running in the pharyngeal plexus
What is the action of the superior pharyngeal constrictor muscle
Pull the posterior pharyngeal wall anteriorly to close off the nasopharynx
What is the action of middle pharyngeal constrictor muscle
Propel the bolus towards the inferior constrictor
What is the action of the inferior pharyngeal constrictor muscle
Propel the bolus towards the oesophagus
Describe the overall action for the longitudinal pharyngeal muscles
Elevate the larynx and shorten the pharynx during swallowing and speaking
Name the 3 pharyngeal longitudinal muscles
- Palatopharyngeus
- Stylopharyngeus
- Salpingopharyngeus
Describe the innervation to the stylopharyngeus
Branches of the glossopharyngeal nerve (CN IX)
Describe the sensory innervation to the different regions of the pharynx
Nasopharynx = CNV2 (maxillary division) Oropharynx = glossopharyngeal nerve (CN IX) Laryngopharynx = vagus nerve (CN X)
Describe the arterial supply to the pharynx
- Pharyngeal branches from the maxillary artery
2. Ascending pharyngeal artery from the ‘medial’ surface of the external carotid
Describe the venous drainage of the pharynx
Pharyngeal veins form a large venous plexus which communicate with:
- Facial vein
- Internal jugular vein
What tonsils form the pharyngeal lymphatic ring
- Palatine
- Lingual
- Pharyngeal
Describe the lymphatic drainage pathway of the pharynx
Lymph drains to retropharyngeal and paratracheal nodes; then onto deep cervical nodes
What nerves contribute to the pharyngeal plexus
- Glossopharyngeal (CN IX)
- Vagus (CN X)
- Sympathetic fibres
- Cranial part of the accessory nerve (CN XI) via the vagus nerve
What significant structures exist in the area immediately posterior to the pharynx
- Anterior pre-vertebral muscles
2. Sympathetic ganglia
Name the 4 anterior pre-vertebral muscles
- Longus capitis
- Longus colli
- Rectus capitis anterior
- Rectus capitis lateralis
Describe the innervation to the 4 anterior pre-vertebral muscles
Longus capitis = anterior rami C1-3
Longus colli = anterior rami C2-6
Rectus capitis anterior = anterior rami C1-2
Rectus capitis lateralis = anterior rami C1-2
What is the overall action of the anterior pre-vertebral muscles
Support the head on the neck, as well as flexion
Where does the sympathetic ganglia extend from, and to
Base of the skull to join the thoracic chain inferiorly
Describe the location of the sympathetic ganglia
Behind the internal and common carotid arteries, medial to the vagus nerve
Name the 3 regions of the sympathetic ganglia
- Superior cervical ganglia
- Middle cervical ganglia
- Inferior cervical ganglia
Name the 3 ganglion regions of the sympathetic ganglia
- Superior cervical ganglion
- Middle cervical ganglion
- Inferior cervical ganglion
What level does the superior cervical ganglion exist
C1 and C2 vertebrae
Where do the grey rami communicantes head out from the superior cervical ganglion
- C1-4 anterior rami
2. Form plexus’ around the common and external carotid arteries
What cranial nerves are supplied by the superior cervical ganglion
CN’s IX, X, and XII
At what level does the middle cervical ganglion exist
At the level of the cricoid cartilage; very small, and occasionally absent
Name other branches that exit from the middle cervical ganglion
- Thyroid branches to the thyroid gland
- Middle cardiac branch to the cardiac plexus
- Ansa cervicalis loops around the subclavian artery
- Grey rami communicantes to anterior rami of C5-6
In around 80% of people, what happens to the inferior cervical ganglion
It fuses with the first thoracic ganglion to form the stellate ganglion
Where is the stellate ganglion located
Anterior to the transverse process of the C7 vertebra, superior to the neck of the 1st rib
Name the branches of the stellate ganglion
- Grey rami communicantes to the anterior rami of C7-8
2. Branches to the deep cardiac plexus
