Bones of the Skull

Flashcards about the bones of the skull

Cranial Sutures

Immobile joints interconnecting the 22 bones of the skull.

Cranial Sutures Description

Synarthrosis, developed after birth, flexible in infancy, important sutures include coronal, sagittal, lambdoid, and squamosal.

Fontanels

Soft membrane gaps between cranial bones allowing brain expansion.

Types of Fontanels

Posterior, anterior, posterolateral, and anterolateral.

Craniosynostosis

Pathological process leading to premature complete ossification of the skull.

Neurocranium

Composed of the calvaria (skull roof) and cranial base; delimits the cranial cavity.

Calvaria

Upper part of the neurocranium composed of flat bones.

Calvaria Bone Structure

Two layers of compact bone tissue separated by the diploe.

Diploe

Cancellous (spongy) bone tissue containing bone marrow and diploic veins.

Frontal Bone

Forms the forehead and superior rim of the orbit.

Frontal Bone Articulations

Parietal bones, sphenoid, zygomatic, nasal, and lacrimal bones.

Parietal Bone

Forms the roof and sides of the cranium.

Parietal Bone Angles

Frontal, occipital, sagittal, and squamous angles.

Occipital Bone

Main bone of the occiput overlying the occipital lobes.

Occipital Bone Parts

Squamous, basilar, and two lateral parts.

Foramen Magnum

Large opening in the occipital bone through which the spinal cord passes.

Exterior Occipital View

Contains three transversal nuchal lines and two occipital condyles.

Temporal Bone

Located on the sides of the cranium housing structures of the ears.

Temporal Bone Parts

Squamous, zygomatic process, tympanic, styloid, and petromastoid.

Cranial Base

Floor of the cranial cavity.

Cranial Base Components

Sphenoid, ethmoid, occipital, frontal, and temporal bones.

Ethmoid Bone

Separates the nasal from the cranial cavity.

Sphenoid Bone

Butterfly-shaped bone anterior to the basilar portion of the occipital bone.

Sphenoid Bone Components

Body, greater wings, lesser wings, and pterygoid processes.

Viscerocranium

Facial skeleton located anterior to the neurocranium.

Zygomatic Bone

Forms the face lateral prominences and parts of the orbit.

Nasal Bone

Forms the bridge of the nose.

Maxillae

Hold the upper teeth and are involved in formation of the orbit, nasal cavity, and palate.

Maxillae Processes

Zygomatic, frontal, alveolar, and palatine processes.

Palatine Bone

Forms the hard palate alongside the maxillae.