Ethmoidal nerves

Ethmoidal nerves are a group of nerves that originate from the ophthalmic nerve, a branch of the trigeminal nerve. They are responsible for providing sensory innervation to the upper nasal cavity and the ethmoidal sinuses. The ethmoidal nerves are divided into two main branches: the anterior and posterior ethmoidal nerves.

Etymology

The term "ethmoidal" is derived from the Greek word "ethmos," meaning sieve, and "eidos," meaning form or shape. This is in reference to the ethmoid bone's sieve-like structure, through which the ethmoidal nerves pass.

Anatomy

The anterior ethmoidal nerve arises from the nasociliary nerve, a branch of the ophthalmic nerve. It passes through the anterior ethmoidal foramen into the anterior cranial fossa, then descends into the nasal cavity through the ethmoidal canal. It provides sensory innervation to the anterior and middle ethmoidal cells, frontal sinus, and the upper part of the nasal septum and lateral wall of the nasal cavity.

The posterior ethmoidal nerve is smaller than the anterior ethmoidal nerve. It also arises from the nasociliary nerve and passes through the posterior ethmoidal foramen to innervate the sphenoidal sinus and the posterior ethmoidal cells.

Clinical significance

Damage to the ethmoidal nerves can result in loss of sensation in the areas they innervate. This can occur due to trauma, infection, or surgical procedures involving the ethmoid bone or sinuses. In some cases, damage to these nerves can also cause referred pain in the forehead and eye area.

Related terms

• Ophthalmic nerve
• Trigeminal nerve
• Nasociliary nerve
• Ethmoid bone
• Ethmoidal foramen
• Ethmoidal cells
• Frontal sinus
• Nasal cavity
• Sphenoidal sinus

Ethmoidal nerves

• Gray's Anatomy illustration of ethmoidal nerves
  Gray's Anatomy illustration of ethmoidal nerves