Podcast
Questions and Answers
Which of the following is NOT an articulation of the ethmoid bone?
Which of the following is NOT an articulation of the ethmoid bone?
What role does the cribriform plate play in the ethmoid bone?
What role does the cribriform plate play in the ethmoid bone?
Which structure within the ethmoidal labyrinth is essential for drainage of the frontal sinus?
Which structure within the ethmoidal labyrinth is essential for drainage of the frontal sinus?
What is the primary function of the turbinates/nasal conchae in the nasal cavity?
What is the primary function of the turbinates/nasal conchae in the nasal cavity?
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Identify the bone projection that resembles a rooster's comb and is located on the upper portion of the vertical lamina of the ethmoid bone.
Identify the bone projection that resembles a rooster's comb and is located on the upper portion of the vertical lamina of the ethmoid bone.
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Which part of the ethmoid bone forms the roof of the nasal cavity?
Which part of the ethmoid bone forms the roof of the nasal cavity?
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What is the main function of the turbinates in the ethmoid bone?
What is the main function of the turbinates in the ethmoid bone?
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Which of the following is NOT a characteristic of the ethmoid bone?
Which of the following is NOT a characteristic of the ethmoid bone?
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The olfactory groove, where the olfactory bulb resides, is located on which part of the ethmoid bone?
The olfactory groove, where the olfactory bulb resides, is located on which part of the ethmoid bone?
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What is the name given to the numerous air cells within the ethmoid bone?
What is the name given to the numerous air cells within the ethmoid bone?
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The ethmoidal labyrinth is found on which face of the lateral masses?
The ethmoidal labyrinth is found on which face of the lateral masses?
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Which anatomical structure is responsible for draining the frontal sinus to the middle meatus?
Which anatomical structure is responsible for draining the frontal sinus to the middle meatus?
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Which of the following accurately describes the relationship between the ethmoid bone and the vomer?
Which of the following accurately describes the relationship between the ethmoid bone and the vomer?
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Flashcards
Ethmoid Bone
Ethmoid Bone
A single, central bone of the skull located postero-inferior to the frontal bone.
Vertical Lamina
Vertical Lamina
Midline portion of the ethmoid bone that divides the nasal cavities.
Cribriiform Plate
Cribriiform Plate
Horizontal lamina of the ethmoid, part of the floor of the anterior cranial fossa.
Lateral Masses
Lateral Masses
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Crista Galli
Crista Galli
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Ethmoidal Cells
Ethmoidal Cells
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Superior Turbinates
Superior Turbinates
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Significance of Ethmoid
Significance of Ethmoid
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Turbinates/Nasal Concha
Turbinates/Nasal Concha
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Perpendicular Lamina
Perpendicular Lamina
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Olfactory Groove
Olfactory Groove
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Study Notes
Ethmoid Bone
- The ethmoid bone is a single, central bone located postero-inferior to the frontal bone.
- It contributes to the central joint of the skull, providing stability.
- It is symmetrical, with its right half mirroring the left.
Structure
- The ethmoid bone consists of three main parts:
- Vertical lamina: Located at the midline of the skull, dividing the nasal cavities.
- Horizontal lamina: Elongated anteroposteriorly; also known as the cribriform plate.
- Lateral masses: Paired cube-shaped structures forming the medial wall of the orbital cavity.
Vertical Lamina
- Composed of two parts:
- Upper portion: Wider, known as the crista galli process, resembling a rooster's comb.
- Lower portion: Known as the perpendicular lamina, acting as the central nasal septum.
- Articulates with the vomer, creating the nasal septum.
Horizontal Lamina (Cribriform Plate)
- It's the horizontal plate of the ethmoid bone.
- Contains two faces:
- Superior face: Part of the floor of the anterior cranial fossa, housing the olfactory groove. This groove holds the olfactory bulb of the first cranial nerve.
- Inferior face: Forms the roof of the nasal cavity.
Lateral Masses
-
Consists of six faces:
- External/Lateral face (Orbital lamina): Forms the medial wall of the orbital cavity.
- Internal/Medial face: Forms the lateral wall of the nasal fossa, containing superior and middle nasal turbinates to increase airflow surface area.
- Superior face: The ethmoidal labyrinth, a region riddled with holes leading to air cells.
- Inferior face: Houses the lower edge of the middle turbinate, the middle nasal meatus, and the uncinate process.
- Posterior face: Articulates with the sphenoid and palatine bones.
- Anterior face: Articulates with the lacrimal bone.
Ethmoidal Cells
- Numerous air cells within the ethmoid bone, collectively termed the ethmoidal labyrinth.
- Anterior ethmoidal cells: Drain into the middle nasal meatus.
- Posterior ethmoidal cells: Drain into the superior nasal meatus.
- Infundibulum: A crucial structure within the ethmoidal labyrinth, allowing the passage of the frontal sinus to the middle nasal meatus.
Significance
- The complex structure aids in air filtration and humidification.
- Essential for the sense of smell.
- Ethmoidal cells contribute to the skull's lightness and stability.
Articulations
- The ethmoid bone articulates with:
- Frontal
- Maxilla
- Palatine
- Vomer
- Sphenoid
- Lacrimal
Important Terms
- Turbinates/Nasal Conchae: Bony projections within the nasal cavity, increasing surface area.
- Meatuses: Channels between turbinates, essential for sinus drainage.
- Cribriform Plate: The horizontal lamina of the ethmoid.
- Olfactory Groove: The structure within the cribriform plate that contains the olfactory bulb.
- Perpendicular Lamina: The vertical lamina forming the nasal septum.
- Crista Galli Process: The upper portion of the vertical lamina, resembling a rooster's comb.
- Ethmoidal Labyrinth: The name for the air cells within the lateral masses.
- Infundibulum: Crucial for frontal sinus drainage.
- Uncinate Process: A projection facilitating ethmoidal cell drainage.
- Remember: The ethmoid bone plays a crucial role in respiration, olfaction, and structural stability.
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Description
Test your knowledge on the anatomy of the ethmoid bone and its significance in the skull. This quiz covers its structure, including the vertical and horizontal laminae, as well as the lateral masses. Dive in to understand the critical role this bone plays in separating the nasal cavities.
