Pharynx, Auditory Tube

Question 1

Gaps between the pharyngeal muscles and structures passing through them?

Answer 1

1) Between upper concave border of Sup Constrictor and base of skull
•Auditory tube
•Levator Veli palatini
•Asceding Palatine artery
•Palatine branch of Ascending pharyngeal A

2) B/w superior and middle constrictor - Stylopharyngeus muscle & Glossopharyngeal nerve supplying it

3) B/w inferior and middle constrictor the Thyrohyoid membrane is pierced by:
Internal Laryngeal nerve and Sup Laryngeal vessels

4) B/w inferior constrictor and esophagus - Recurrent Laryngeal nerve and Inferior Laryngeal vessels

Question 2

Origins of the three constrictor muscles and insertion?

Answer 2

1) Superior constrictor arises from
•Pterygoid Hamulus
•Pterygomandibar Raphe
•Internal surface of Mandible begins the 3rd molar at the post end of mylohyoid line

2) Middle Constrictor arises from:
•Stylohyoid ligament
•Lesser Cornu of hyoid bone
•Upper border of greater cornu

3) Inferior Constrictor arises from:
•Thyropharyngeus part from oblique line on the thyroid lamina, inferior thyroid tubercle, inferior Cornua of thyroid cartilage and the fascia covering Cricothyroid.
•Cricopharyngeus from the cricoid cartilage behind origin of cricothyroid muscle.

Insertion: All 3 muscles into the MEDIAN FIBROUS RAPHE on posterior wall of pharynx which is ATTACHED SUPERIORLY TO THE PHARYNGEAL TUBERCLE ON BASSIOCCIPUT.

Question 3

Name the 3 longitudinal muscles of pharynx and their attachments?

Answer 3

Origin

1. Stylopharyngeus - arises from the medial surface of styloid process
2. Palatopharyngeus- Upper surface of palatine aponeurosis (posterior fasciculus) & posterior border of hard palate (anterior fasciculus)
3. Salpingopharyngeus - cartilaginous part of auditory tube

Insertion
All three get inserted on the Posterior border of lamina of Thyroid cartilage.

Question 4

What is the nerve supply and vascular supply of Auditory tube?

Answer 4

NERVE SUPPLY
•Most of it, except the Pharyngral opening is supplied by the Glossopharyngeal nerve via tympanic plexus.
•Pharyngeal opening supplied by Pharyngeal branch of Pterygopalatine Ganglion.

BLOOD SUPPLY 
1) Ascending pharyngeal A
3) Middle Meningeal A
4) Artery of Pterygoid Canal
VENOUS DRAINAGE 
Pharyngeal and Pterygoid plexus.

Question 5

What are the age changes of Auditory Tube? Clinal Importance?

Answer 5

In an infant,
the Auditory tube is almost half the length (18mm) as in an adult (36mm)
It is more horizontal (10 degrees angle with horizontal plane)
It does not have an angular ion at the isthmus.

In adult, it’s longer, oblique (45 degree) and had an angularion at isthmus.

Question 6

Extent and Subdivisions of Pharynx.

Answer 6

Extent: Base of skull to lower border of Cricoid cartilage (c6)

Subdivisions:

1. Nasopharynx- Base of skull to lower border of soft palate.
2. Oropharynx - Lower border of soft palate to upper end of epiglottis
3. Laryngopharynx - Upper end of epiglottis to lower border of cricoid

Question 7

Features of Nasopharynx.

Answer 7

Boundaries

• Anteriorly the post nasal apertures
• Floor- Soft palate (upper surface) and pharyngeal isthmus
• Behind C1 vertebral body
• Roof- base of skull
• Laterally the medial pterygoid plate

Features Lateral wall:

1) Opening of Auditory tube
2) Tubal elevation
3) 2 folds extending from Tubal elevation
3) Retropharyngeal Recess(Fossa of Rosenmuller)

Features of Roof: Nasopharyngeal Tonsil

Question 8

Oropharynx boundaries and features.

Answer 8

Boundaries

1) Roof- Lower surface of soft palate, Pharyngeal isthmus
2) Ant- Oropharyngeal isthmus, pharyngeal part of tongue
3) Post- C2 and C3 vertebral bodies
4) Floor- Post 1/3rd of tongue
5) Laterally- Pterygomandibular raphe, tongue , Mandible

Features :

• Lateral wall- palatine tonsil
• Anterior wall:
  1) Lingual tonsil
  2) Upper free end of epiglottis
  3) Glossoepiglottic folds
  4) Vallecula