Posterior ethmoidal artery
Arteria ethmoidea posterior
A small ophthalmic branch that leaves the orbit through the posterior ethmoidal canal for the back ethmoidal cells, dura and septum.
At a glance
- English
- Posterior ethmoidal artery
- Latin (TA2)
- Arteria ethmoidea posterior
- System
- Artery
- Region
- Head
- Side
- Paired, left and right
About the posterior ethmoidal artery
The posterior ethmoidal artery is one of the orbital branches of the ophthalmic artery. It is smaller than its partner, the anterior ethmoidal artery, and is sometimes missing. It arises as the ophthalmic artery runs forwards along the medial wall of the orbit.
It passes medially between the upper edge of medial rectus and superior oblique to reach the posterior ethmoidal foramen, at the junction of the orbital roof and medial wall, and enters the posterior ethmoidal canal. Inside the canal it supplies the posterior ethmoidal air cells. It then emerges into the anterior cranial fossa, where it usually gives a meningeal twig for the dura covering the cribriform plate and planum, before descending through the cribriform plate into the upper nasal cavity.
In the nose it supplies the mucosa of the upper part of the septum and the adjacent lateral wall, including the superior concha. There it anastomoses with branches of the sphenopalatine artery, so linking the internal carotid supply, through the ophthalmic artery, with the external carotid supply, through the maxillary artery.
The posterior ethmoidal foramen is an important landmark in orbital surgery. It lies a short distance in front of the optic canal, so the artery helps surgeons judge how close they are to the optic nerve when working on the medial orbital wall. In severe nosebleeds that come from high in the nose and do not settle with treatment of the sphenopalatine artery, the ethmoidal arteries may need to be tied or clipped. Because the internal and external carotid systems meet here, embolisation of the external carotid alone may not stop such bleeding.
Course and supply
- Arises from
- The ophthalmic artery, as it runs along the medial wall of the orbit.
- Ends in
- Ends in the upper nasal mucosa of the septum and lateral wall after crossing the posterior ethmoidal canal and anterior cranial fossa.
- Supplies
- Supplies the posterior ethmoidal air cells, the dura over the cribriform region and the mucosa high on the nasal septum.
Anthromica
See the posterior ethmoidal artery where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
