Airway anatomy: Pharynx

BLOOD SUPPLY

ECA branches:

1. Ascending pharyngeal

2. Tonsillar (via facial artery)

3. Maxillary

4. Lingual

Venous drainage: pharyngeal veins → internal jugular vein

Lymphatics: deep cervical LN (along IJ), retropharyngeal LN, or paratracheal LN.

The Waldeyer ring of lymphoid tissue is formed by:

● pharyngeal tonsils (adenoids) superiorly

● palatine and tubal tonsils (around auditory tubes) laterally

● lingual tonsils (posterior tongue) inferiorly

SENSORY INNERVATION

CN V2, maxillary div. trigeminal n. – nasopharynx

CN IX, glossopharyngeal n. – oropharynx

Internal laryngeal nerve (via CN X, vagus n.) – laryngeal pharynx

MOTOR INNERVATION

CN IX – stylopharyngeus m. (“dressed to the 9s… stylin’”)

CN V – all others:

Constrictors

1. Superior constrictor m.

2. Middle constrictor m.

3. Inferior constrictor m.

4. Cricopharyngeus m.

Longitudinal

1. Palatopharyngeus m.

2. Salpingopharyngeus m.

3. (Stylopharyngeus – innervated by CN IX)