Parietal bone: Difference between revisions

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'''Parietal bone'''
{{Short description|Bone forming part of the skull}}
{{Anatomy}}


The '''parietal bone''' is a bone in the human skull which, when joined together, form the sides and roof of the cranium. Each bone is roughly quadrilateral in form, and has two surfaces, four borders, and four angles. It is named from the Latin ''paries'' (-ietis), wall.
The '''parietal bone''' is a paired, flat bone located on the lateral sides of the [[skull]]. It forms a significant portion of the [[cranial vault]], which encases and protects the [[brain]].


==Structure==
==Anatomy==
The parietal bone articulates with the [[frontal bone]] via the [[coronal suture]]. Posteriorly, it articulates with the [[occipital bone]] via the [[lambdoid suture]]. The sagittal suture joins the two parietal bones together. Lastly, it articulates with the [[temporal bone]] via the [[squamosal suture]].
The parietal bones are situated between the [[frontal bone]] anteriorly and the [[occipital bone]] posteriorly. They are bordered inferiorly by the [[temporal bone]] and the [[sphenoid bone]]. Each parietal bone is roughly quadrilateral in shape and has two surfaces, four borders, and four angles.
 
===Surfaces===
The external surface of the parietal bone is convex and smooth, providing attachment for the [[temporalis muscle]]. The internal surface is concave and contains grooves for the [[middle meningeal artery]] and [[venous sinuses]].


===Borders===
===Borders===
The parietal bone has four borders:
* '''Sagittal border''': The superior border, which articulates with the opposite parietal bone at the [[sagittal suture]].
 
* '''Squamous border''': The inferior border, which articulates with the [[temporal bone]].
* The frontal border is part of the [[coronal suture]].
* '''Frontal border''': The anterior border, which articulates with the [[frontal bone]] at the [[coronal suture]].
* The sagittal border is part of the [[sagittal suture]].
* '''Occipital border''': The posterior border, which articulates with the [[occipital bone]] at the [[lambdoid suture]].
* The occipital border is part of the [[lambdoid suture]].
* The squamous border is part of the [[squamosal suture]].


===Angles===
===Angles===
The parietal bone has four angles:
* '''Frontal angle''': Located at the junction of the coronal and sagittal sutures.
* '''Sphenoidal angle''': Located at the junction of the coronal and squamous sutures.
* '''Occipital angle''': Located at the junction of the sagittal and lambdoid sutures.
* '''Mastoid angle''': Located at the junction of the lambdoid and squamous sutures.


* The frontal angle is the point at which the bone begins to curve inward.
==Development==
* The occipital angle is the point at which the bone begins to curve outward.
The parietal bone develops from two primary ossification centers that appear in the membrane covering the developing brain. These centers appear around the eighth week of fetal development and fuse to form a single bone by birth. The bone continues to grow and remodel throughout childhood and adolescence.
* The sphenoidal angle is the point at which the bone begins to curve inward.
* The mastoid angle is the point at which the bone begins to curve outward.


==Development==
==Function==
The parietal bone is ossified in membrane from a single center, which appears at the parietal eminence about the eighth week of fetal life.
The primary function of the parietal bone is to protect the brain by forming part of the cranial vault. It also provides attachment points for muscles involved in mastication and head movement.


==Clinical significance==
==Clinical significance==
Damage to the parietal lobe can result in [[sensory loss]], [[impaired spatial processing]], and [[disorders of language]].
Fractures of the parietal bone can occur due to trauma and may lead to complications such as [[epidural hematoma]] if the middle meningeal artery is damaged. Surgical interventions may be necessary in severe cases.


==See also==
==Images==
* [[Cranium]]
[[File:Parietal bone lateral view.png|thumb|right|Lateral view of the parietal bone (highlighted in green).]]
* [[Human skull]]
[[File:Parietal bone internal view.png|thumb|left|Internal view of the parietal bone showing grooves for the middle meningeal artery.]]
* [[Suture (anatomy)]]


==References==
==Related pages==
<references />
* [[Skull]]
 
* [[Cranial sutures]]
==External links==
* [[Frontal bone]]
* [https://www.britannica.com/science/parietal-bone Britannica - Parietal Bone]
* [[Occipital bone]]
* [[Temporal bone]]


[[Category:Skull]]
[[Category:Skull]]
[[Category:Bones of the head and neck]]
[[Category:Bones of the head and neck]]
{{stub}}
<gallery>
File:Parietal_bone_posterior2.png|Parietal bone
File:Gray132.png|Parietal bone
File:Gray133.png|Parietal bone
File:Left_parietal_boen_-_animation.gif|Parietal bone
File:Sagittal_suture_2.jpg|Parietal bone
File:SchaedelSeitlichSutur1.png|Parietal bone
File:SchaedelSeitlichSutur3.png|Parietal bone
File:Lambdoid_suture.png|Parietal bone
File:Tuatara_skull_diagram.svg|Parietal bone
File:Parietal_bone_animation2.gif|Parietal bone
File:Parietal_bone.jpg|Parietal bone
File:HSCA-JFK-head-7-125.jpg|Parietal bone
</gallery>

Revision as of 17:44, 18 February 2025

Bone forming part of the skull


The parietal bone is a paired, flat bone located on the lateral sides of the skull. It forms a significant portion of the cranial vault, which encases and protects the brain.

Anatomy

The parietal bones are situated between the frontal bone anteriorly and the occipital bone posteriorly. They are bordered inferiorly by the temporal bone and the sphenoid bone. Each parietal bone is roughly quadrilateral in shape and has two surfaces, four borders, and four angles.

Surfaces

The external surface of the parietal bone is convex and smooth, providing attachment for the temporalis muscle. The internal surface is concave and contains grooves for the middle meningeal artery and venous sinuses.

Borders

Angles

  • Frontal angle: Located at the junction of the coronal and sagittal sutures.
  • Sphenoidal angle: Located at the junction of the coronal and squamous sutures.
  • Occipital angle: Located at the junction of the sagittal and lambdoid sutures.
  • Mastoid angle: Located at the junction of the lambdoid and squamous sutures.

Development

The parietal bone develops from two primary ossification centers that appear in the membrane covering the developing brain. These centers appear around the eighth week of fetal development and fuse to form a single bone by birth. The bone continues to grow and remodel throughout childhood and adolescence.

Function

The primary function of the parietal bone is to protect the brain by forming part of the cranial vault. It also provides attachment points for muscles involved in mastication and head movement.

Clinical significance

Fractures of the parietal bone can occur due to trauma and may lead to complications such as epidural hematoma if the middle meningeal artery is damaged. Surgical interventions may be necessary in severe cases.

Images

File:Parietal bone lateral view.png
Lateral view of the parietal bone (highlighted in green).
File:Parietal bone internal view.png
Internal view of the parietal bone showing grooves for the middle meningeal artery.

Related pages