Lecture 12.1 Pharynx

Question 1

What are the 3 parts of the pharynx and the associated mucosal structures with each

Answer 1

1. Nasopharynx: pharyngeal tonsil. opening of eustachian tube, torus tubarius, salpingopharyngeal fold and pharyngeal recess
2. Oropharynx: Palatoglossal arch, palatine tonsil, palatopharyngeal arch
3. Laryngopharynx: laryngeal inlet

Question 2

What are the 3 constrictor muscles corresponding to the 3 parts of the pharynx of the pharyngeal wall and their attachments

Answer 2

1. Superior

attached to base of skull at the

• sphenoid fossa,
• eustachian tube,
• petrous part of temporal bone,
• pharyngeal tubercle on occipital bone then to the other side

+ anteriorly medial pterygoid plate and
-pterygomandibular raphe.

2. Middle:
   - Upper margin of the greater horn of the hyoid bone + adjacent lesser horn and
   - stylohyoid ligament
3. Inferior
   - Cricoid cartilage,
   - oblique line of the thyroid cartilage
   - cricothyroid muscle (ligament that spans between the earlier attachments)

Question 3

Which constrictor muscle is laid on top of which.

What is the function and posterior attachment of the constrictor muscles

Answer 3

From outside (on top to deep) 
Inferior ->middle->superior 

Function is to constrict the pharynx so when done sequentially results in peristaltic swallowing for food bolus to go to oesophagus

Posterior attachment is the pharyngeal raphe

Question 4

What are the 3 longitudinal muscles of the pharynx, where do they attach

deep to constrictors

Answer 4

1. Salpingopharyngeus:
   Attaches from eustachian tube to blend the superior constrictor, continuing to the middle
2. Palatopharyngeus
   Attaches from the upper surface of palatine aponeurosis to the middle and inferior constrictor
3. Stylopharyngeus: Attaches from styloid process, enters between superior and middle then attaches to middle and inferior constrictor

Question 5

What is the function of the longitudinal muscles

Answer 5

• Elevate the pharynx,
• structural support for the pharynx as it has no inferior attachments.
• Assisting with swallowing, pulling up and over a bolus of food and pushing it through the pharynx to the oesophagus.

Question 6

What is the innervation of the constrictor and longitudinal muscles

Answer 6

All CN10 except for stylopharyngeus which is supplied by CN9

Question 7

What is the posterior aspect of the pretracheal fascia sitting right behind the pharynx called and what is the lower part of this posterior aspect

Answer 7

Buccopharyngeal fascia and pharyngobasilar fascia

Question 8

What are the structures that pass in the gap in the posterolateral free edge

a) Above the superior constrictor
b) between the Middle and inferior constrictor
c) Below the inferior

Answer 8

a) Tensor and levator veli palatini
b) Internal laryngeal vessels and nerve (branch of the superior laryngeal nerve)
c) Recurrent laryngeal nerve (coming from the lower neck travelling in the tracheo-oesophageal groove)
- Inferior laryngeal vessels

Question 9

What are the structures that pass through the Oropharyngeal triangle - what is this area

Answer 9

This is between the superior and middle constrictor and heading toward the free edge of mylohyoid

• All structures going to the 1st potential and second space of the oral cavity
  = CN12, CN9, lingual artery and nerve + 2 veins

+ stylopharyngeus muscle

Question 10

What is the clinical importance of the pharyngeal tonsil

Answer 10

It is a lymphoid tissue which if enlarged in babies less than 6months leads to poor sleep/behaviour because babies are predominantly nose breathers, so the pharyngeal tonsil can block the nasopharynx and cause them to wake up

Question 11

What is arterial supply to the upper and lower part of the pharynx.
What is the supply to the palatine tonsil

Answer 11

1. Upper: Ext carotid branches - eg. lingual, maxillary, facial
2. Lower: Subclavian branches: inferior thyroid artery of the thyrocervical branch
3. Tonsilar branch of the facial artery supplies palatine tonsil

Question 12

What is the venous and lymphatic drainage of the pharynx.

What nodes drain the palatine tonsils

Answer 12

Venous:
- superiorly to the pterygoid plexus and inferiorly to the facial and internal jugular vein

Lymphatic:
- Deep cervical nodes : paratracheal, infrahyoid, retropharyngeal nodes

P. tonsils drained by the jugulodigastric nodes

Question 13

What is the sensory innervation to the 3 parts of the pharynx

Answer 13

Naso: CNV2 (maxillary)

Oro: CN9

Laryngo: CN10

(But in reality, there is nerve plexus between 9 and 10 so often “both” is ok answer as well