Anatomy & Organs

Ethmoid cells – structure, function & diseases

Ethmoidal cells

The ethmoid cells are part of the ethmoid bone , which is found in the interior of the frontal, nasal, and orbital cavities . In addition to the stability function, they have a connection to the nerves and are involved in smell perception. Fractures, nerve damage, tumors , inflammation and polyp formation can be possible diseases associated with the ethmoid cells.

What are ethmoid cells?

The ethmoid cells (cellulae ethmoidale) belong to the ethmoid bone (os ethmoidale), which is a bony area in the brain skull and the eye and nasal cavities.

The naming is based on the sieve-like structure of the holey bone .

They are not “cells” in the medical-biological sense, but describe the air-filled cavities.

The entirety of the ethmoidal cells is also referred to as the ethmoidal labyrinth (Labyrinthus ethmoidalis).

Anatomy & Structure

Anatomically, the ethmoid bone is located in an area that protrudes into and delimits both the frontal sinus and the nasal and ocular cavities. As a bony branch, the ethmoid cells are penetrated by chambers or cavities (pneumatization spaces).

The ethmoid bones are thin-walled and have relatively large holes. Adjacent to the frontal sinus are about eight to ten ethmoid cells. In a broader sense, the ethmoid cells are innervated by branches of the fifth cranial nerve ( trigeminal nerve ). On the one hand, nerve cords reach into the eye socket via the rear ethmoidal cells and have a connection there to the paired optic nerve ( nervus opticus ). On the other hand, the nerve cords of the anterior ethmoid cells extend over the ethmoid plate (lamina cribrosa) into the nasal cavity (nervus nasociliaris).

The lamina cribrosa is one of the four different bone plates (laminae) of the ethmoid bone. The pneumatization spaces of the paranasal sinuses are lined with mucous membrane and ciliated epithelium. In the nasal passage, the corresponding nerves supply the nasal mucous membranes via the ethmoid cells.

Function & Tasks

The ethmoid as a whole is responsible for stability between the regions involved ( skull base , eye socket, nasal cavities). At the same time, it divides areas such as the base of the skull from the nasal cavity . Or the middle ethmoid, which together with the ploughshare bone (vomer) forms the nasal septum. It separates the anatomical structures. The olfactory system is directly related to the ethmoid cells.

Our olfactory perception comes about through the olfactory nerves, which are connected to the olfactory bulb (olfactory bulb) and the nasal cavity via the cavities of the ethmoid plate . The cavities in the ethmoid plate make it possible for the nerves to pass through and thus for olfactory perception. If the smell is detected via the nose , more precisely via the olfactory receptor cells on the nasal mucosa, the stimulus is passed on via the olfactory bulb to the cerebral cortex. Via the branched connection with the fifth cranial nerve, the eye nerve (Nervus ophthalmicus) and nerve branches of the upper jaw ( Nervus maxillaris) and lower jaw (Nervus mandibularis), which is responsible for the chewing movement, among other things. Thus, the ethmoid cells play an important role in the transmission of stimuli.


Diseases that affect the ethmoid cells can be caused by anatomical malformations that can lead to chronic diseases.

The ethmoid cells can also be affected by fractures of the bone plates, diseases of the nerve structures, and infections and disorders caused by bacteria and viruses . It should not be forgotten that allergic reactions can also trigger inflammation. Since the ethmoid is in a sensitive area that can be accessed in various ways, the regions involved are particularly susceptible to disease. The best-known disease is inflammation of the paranasal sinuses ( sinusitis ). A distinction is made between acute and chronic sinusitis. The ethmoid cells are part of the paranasal sinuses (sinus paranasales). Viruses, bacteria or allergiesthe mucous membrane of the paranasal sinuses becomes inflamed and promotes swelling.

As a result, suppuration can occur. If pus is encapsulated in a cavity, it is called an empyema. The paranasal sinuses also include the maxillary sinus, the sphenoid sinus and the frontal sinus. These regions can be affected as the inflammation progresses. The disease of all parts of the paranasal sinuses is called pansinusitis. Antibiotics, local or oral cortisone preparations and special nasal rinses are used to treat sinusitis. If the disease has progressed so far that medication does not improve it, surgery may be indicated.

Removal of the ethmoid cells (ethmoidectomy) or partial surgical sanitation (removal of the increased mucosa, polyps) is also indicated in the case of polyp formation (increase in tissue). Inflammatory processes that spread through the eye and frontal sinuses to the brain become dangerous. Bacterial infection of the frontal sinus can lead to meningitis. Early diagnosis of symptoms can prevent such an ascending inflammation. Anatomical malformations can also promote chronic inflammation. Fractures or injuries to the base of the skull and the ethmoid plates increase the risk of CSF (brain fluid) leaking. Inflammation can occur in the area of ​​the maxillary sinus .

Tooth root inflammation or purulent abscesses are often the cause of other diseases of the maxillary and paranasal sinuses. The connecting path between the upper jaw and the cranial nerve runs via the maxillary nerve. Disorders of the nerve pathways of the ethmoidal cell system include neuralgia, such as trigeminal neuralgia : a facial pain caused by the fifth cranial nerve (nervus trigeminal nerve) and often resulting from a sinus infection . Diseases related to the ethmoid cells also include tumors and cyst formations that affect nasal breathing and the natural outflow of secretions. Ethmoid cells belong to a complex structure that includes the eyes , brain, smell, chewing, breathing are indirectly involved and just as far-reaching can be diseases associated with them.

Lisa Newlon
 | Website

Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.