Anatomy of the Skull Base and Infratemporal Fossa
John C Watkinson, Raymond W Clarke, Christopher P Aldren, Doris-Eva Bamiou, Raymond W Clarke, Richard M Irving, Haytham Kubba, Shakeel R Saeed in Paediatrics, The Ear, Skull Base, 2018
The ethmoid bone consists of: the central perpendicular platethe cribriform platethe paired labyrinths. The midline perpendicular plate forms the central superior aspect of the nasal septum, articulating anteroinferiorly with the quadrilateral cartilage and posteroinferiorly with the vomer. It extends superiorly as the crista galli; either side of the crista lie the cribriform plates, through which pass 20 or so olfactory nerve filaments on each side. The labyrinths, containing numerous air cells, lie medial to the orbit and form part of the lateral wall of the nose, being anterior to the body of the sphenoid. They occupy much of the upper part of the maxillary hiatus, a large defect in the medial aspect of the maxilla, itself closed by several bones, and the medial aspect of these is surgically important in endoscopic sinus surgery. The superior and middle conchae (‘turbinates’) are part of the ethmoidal labyrinth, as is the bulla ethmoidalis anteriorly. The lamina papyracea, the paper-thin orbital plate of the ethmoid, separates the ethmoid sinuses from the orbital cavity, knowledge of which is important for endoscopic access to the medial aspect of the orbit, such as for (medial) periorbital abscess drainage, orbital decompression or access to infraorbital/intrazonal tumours.
Sinus headache and nasal disease
Stephen D. Silberstein, Richard B. Upton, Peter J. Goadsby in Headache in Clinical Practice, 2018
The ethmoid bone, a T-shaped structure that supports the bilateral ethmoid labyrinth, forms the lateral nasal wall. The horizontal limb of the T is formed by the cribriform plate, from which the ethmoid labyrinth is suspended. This is a complex structure with multiple bony septa and the medial projections of the superior and middle turbinates. Lateral to the uncinate process, which is a secondary projection of the ethmoid bone, is the infundibuium, a recess into which the maxillary sinus drains. The infundibuium drains into the hiatus semilunaris, which in turn drains into the middle meatus, which is located between the uncinate process and the middle turbinate. The frontal sinus drains into the frontal recess, which may drain into either the middle meatus or the ethmoidal infundibuium. This region is known as the osteomeatal complex11 (maxillary sinus ostium, infundibuium, hiatus semilunaris, middle turbinate, ethmoidal bulla, and frontal ostium). The sphenoidal sinus and posterior ethmoidal cells drain into the sphenoethmoidal recess (Figure 14.2).
Anatomy of the Nose and Paranasal Sinuses
John C Watkinson, Raymond W Clarke, Louise Jayne Clark, Adam J Donne, R James A England, Hisham M Mehanna, Gerald William McGarry, Sean Carrie in Basic Sciences Endocrine Surgery Rhinology, 2018
The bony portion is comprised of the perpendicular plate of the ethmoid bone, vomer, maxillary crest and palatine bone (Figure 87.10). The perpendicular plate of the ethmoid forms the upper one-third of the nasal septum. It is continuous superiorly with the cribriform plate and crista galli and abuts a variable amount of the nasal and frontal bones. Posteriorly the perpendicular plate articulates with the sphenoid crest, posteroinferiorly with the vomer and anteroinferiorly with the septal cartilage. The vomer forms the posterior and inferior nasal septum and articulates by its two alae with the sphenoid rostrum creating the vomerovaginal canals through which the pharyngeal branches of the maxillary artery travel. The inferior border of the vomer articulates with the nasal crest formed by the maxillary and palatine bones. The anterior border articulates with the septal cartilage and the posterior edge of the vomer forms the posterior free edge of the septum.
Nanotechnologies for intranasal drug delivery: an update of literature
Published in Pharmaceutical Development and Technology, 2021
Rosamaria Lombardo, Teresa Musumeci, Claudia Carbone, Rosario Pignatello
The skin that covers the cartilage has a lot of sebaceous glands, while the nostrils, which are the interior part of the nose and the first part of the nose cavity, are covered by mucosa. The name of this part, which constitutes the interior part of the nose, is vestibule. Inside the nose there are the olfactory region, formed by olfactory cells, and the respiratory region which is covered by pseudostratified ciliate epithelium, where also there are caliciform mucipar cells secreting mucus. The ethmoid bone, which constitutes the internal nose, has horizontal position and a flat shape where resides the cribriform lamina which separates the nasal cavity from the brain. This latter has some perforations, called foramina, through which the olfactory nerve (first cranial nerves) passes to arrive to the nasal cavity. As the nerve is not protected by BBB and by the white substance of Schwann, this is the only site of our body where the CNS is in direct contact with the external environment (Gizurarson 2012).
The Endoscopic Transnasal Approach to Orbital Tumors: A Review
Published in Seminars in Ophthalmology, 2021
Edith R. Reshef, Benjamin S. Bleier, Suzanne K. Freitag
The orbital surgeon should be familiar with the pertinent anatomy of the sinonasal cavity. The superior aspect of the nasal cavity has been separated from the orbit by the adjacent anterior and posterior ethmoid sinuses, which drain to the middle and superior meatus, respectively, and by the lamina papyracea, derived from the ethmoid bone to form a large portion of the medial wall of the orbit. The anterior and posterior ethmoids are divided by the basal lamella of the middle turbinate. The sphenoid sinuses lie posterior to the nasal cavity, communicating via the sphenoethmoidal recess. The basal lamella of the superior turbinate separates the sphenoid ostia from the posterior ethmoid sinuses. Inferior to the orbit and lateral to the nasal cavity lies the maxillary sinus, which drains to the middle meatus via the maxillary ostium (Figure 1).
Olfactory nerve schwannoma: how human anatomy and electron microscopy can help to solve an intriguing scientific puzzle
Published in Ultrastructural Pathology, 2022
Fabbri Vp, Valentina Papa, Tonon C, Agati R, Toni F, Zoli M, Mazzatenta D, Fioravanti A, Badaloni F, Cenacchi G, Foschini Mp, Asioli S
Another intriguing anatomic theory about the origin of OGS is related to the presence of the nervus terminalis (recognized as cranial pair zero, CN0).8 Originally discovered in 1878 by Fritsch in the brain of the sharks and then described also in humans (1913), this nerve originates in the olfactory placode. It is observed in human embryos and less recognizable in adults. Fibers originating in the nasal cavity passes into the cranium through the middle area of the cribriform plate of the ethmoid bone. The nervus terminalis shows ganglion cells, that sometimes form clusters, normally one or two located at the base of the crista Galli, the so-called ganglion of the nervus terminalis. Its function is uncertain. Despite some studies that did not find Schwann cells in CN0 of mice9 other authors have shown that the migrating GnRH cells of the nervus terminalis are accompanied by the presumptive Schwann cells precursors in the Odontocetes.10
Related Knowledge Centers
- Anterior Cranial Fossa
- Bone
- Cribriform Plate
- Skull
- Brain
- Nasal Cavity
- Nose
- Orbit
- Ethmoidal Labyrinth
- Perpendicular Plate of Ethmoid Bone