Pharyngeal Anatomy and Innervation

The Lingual Artery

• Venous drainage: pharyngeal veins drain into the internal jugular vein.
• Nerve supply (pharyngeal plexus):
• Motor: pharyngeal branches of the vagus (“cranial accessory”) and glossopharyngeal nerves.
• Sensory:
  • Nasopharynx: mainly by the maxillary nerve.
  • Oropharynx: mainly by the glossopharyngeal nerve.
  • Laryngeopharynx: by the internal laryngeal branch of the vagus nerve.

The Palatine Tonsils

• Relations:
• Anteriorly: palatoglossal fold.
• Posteriorly: palatopharyngeal fold.
• Superiorly: soft palate.
• Inferiorly: posterior third of the tongue.
• Medial: oropharynx.
• Lateral: superior constrictor of the pharynx and the external palatine vein.
• Arterial supply: tonsilar branch of the facial artery.
• Lymphatic drainage: deep cervical (jugulodigastric node).

Paranasal Air Sinuses

• Functions:
• Decrease the weight of the skull.
• Provide the optimum temperature and humidity to the inspired air.
• Give resonance to the voice.
• Drainage:
• Frontal air sinuses: infundibulum (middle meatus).
• Maxilary air sinuses: hiatus semilunaris (middle meatus).
• Ethmoidal air sinuses:
  • Anterior: hiatus semilunaris (middle meatus).
  • Middle: bulla ethmoidalis (middle meatus).
  • Posterior: superior meatus.
• Sphenoidal air sinuses: sphenoethmoidal recess.

Nasal Cavity

• Nerves:
• Olfactory nerves in the roof (the olfactory mucosa).
• Branches from the maxillary nerve to the rest of nasal walls.
• Nasopalatine nerve (from sphenopalatine ganglion).
• Nasal branches of the greater palatine nerves.

The Falx Cerebri

• A sickle-shaped fold of the inner layer of the cranial dura matter.
• Separates the cerebral hemispheres from each other.
• Attached to the crista gale anteriorly and the beak of the tentorium cerebelli posteriorly.
• Has a superior convex border and an inferior concave free border.
• Lodges the following venous dural sinuses:
• Superior sagittal sinus in its attached superior border.
• Inferior sagittal sinus in its free inferior border.
• Straight sinus in its posterior wider end.

The Tentorium Cerebelli

• A tent-like shaped fold of the inner layer of the cranial dura matter.
• Separates the occipital lobes of the cerebral hemispheres from the superior surface of the cerebellum.
• Has an outer convex attached border and an inner concave free border.
• Attached to the posterior clinoid process, tip and superior border of the petrous part of the temporal bone, the lips of the transverse sulcus, and the internal occipital protuberance.
• Lodges the following venous dural sinuses.

Nasopharynx

• The upper part of the pharynx that communicates freely with the nasal cavities anteriorly through the posterior nasal apertures.
• Features:
• Pharyngotympanic tube.
• Tubal elevation.
• Salpigopharyngeal fold that contains the salpigopharyngeus muscle.
• Pharyngeal recess above the tubal elevation.
• Roof occupied by the pharyngeal tonsil.
• Floor formed by the soft palate.
• Posteriorly, the basisphenoid and basioccipital bones.

Muscles of the Soft Palate

• Tensor palati: Mandibular nerve, tens the soft palate.
• Levator palati: Pharyngeal plexus of nerves, elevates the soft palate.
• Palatopharyngeus: Pharyngeal plexus of nerves, elevates the pharynx during swallowing.
• Salpigopharyngeus: Pharyngeal plexus of nerves, pulls the tongue upwards and backwards during swallowing.