Frontal Bone Anatomy
Ethmoid Bone Anatomy
Introduction to Ethmoid bone anatomy:
- The ethmoid bone (Gr., ethmos – sieve) is a spongy, cuboid-shaped cranial bone located at the top of the nasal cavity and between the two orbits.
- It primarily consists of two lateral masses (containing the ethmoid air cells or ethmoid sinuses) and several projections that extend into the nasal cavity and cranial floor.
Markings of the Ethmoid Bone:
- Orbital plate (or orbital lamina, lami-na papyracea) – thin plate along the lateral margin of the ethmoid labyrinth (or lateral mass); forms part of the medial wall of the orbit. [Coronal view /Orbital view ]
- Perpendicular plate – thin vertical plate that extends down into nasal cavity; articulates with vomer bone to form bony nasal septum. [Anterior view /Coronal view /Sagittal view ]
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- Middle turbinate (or middle concha, plural = conchae) – thin plate that extends down into nasal cavity lateral to perpendicular plate; covered with mucous membrane, which warms, moistens, and cleans inhaled air. [Coronal view /Anterior view ]
- Superior turbinate – (or superior con-cha) – short, thin, plate that extends down into the nasal cavity just above the middle turbinate; serves same functions as middle turbinate. [Coronal view ]
- Lateral mass (or ethmoid labyrinth) – region of bone lateral to perpendicular plate; contains many mucous-lined air cells (the ethmoid sinuses) that open into nasal cavity. [Coronal view ]
- Cribriform plate (L., cribum = sieve) – a horizontal plate (or lamina) in cranial floor and roof of nasal cavity that articulates with the frontal bone. [Coronal view /Sagittal view /Cranial floor view]
- Crista galli (or L. crest of the cock) – thin vertical plate that extends up from cribiform plate; attachment point for the falx cerebri (= part of the connective tissues that surround and protect the brain). [Coronal view /Cranial floor view /Sagittal view ]
Anterior view: Show/Hide answers
Coronal view: Show/Hide answers
Midsagittal view: Show/Hide answers
Cranial Floor view: Show/Hide answers