ANATOMY PART 1- Bones of the Skull Flashcards
of bones in the cranium?
divided into what 2 sections?
cranial cavity divided into?
22 bones
neurocranium and viscerocranium
upper domed part and the base of the skull
Cranial Sutures (synarthrosis)
coronal, sagittal, lambdoid, squarrious
Synarthrosis/Suture
A suture is a type of synarthrosis- a joint that allows little to NO movement
- developed after birth over course of 2 YEARS
- flexible in INFANCY/early childhood
(fibrous strong immobile bands between immovable bones)
Fontanels
soft membrane gaps between cranial bones of calvaria
- allow rapid growth of brain
- close after birth, this is what allows them to move through birth canal since its flexible
6 Fontanels
posterior, anterior, (left and right) posterolateral (mastoid), anterolateral (sphenoid)
Craniosynostosis
pathological process leading to complete ossification PREMATURELY (of the fontanels)
Neurocranium
composed of calvaria, skull roof formed by flat bones and cranial base, cartilaginous part, delimitates the cranial cavity, communicates below the vertebral canal through foramen magnum
calvaria=top part of skull
this is split up into the frontal, occipital
Calvaria
upper part of neurocranium
- composed of FLAT bones
- smooth outer convex surface, inner concave surface
Diploe
cancellous (spongy) bone tissue containing bone marrow and diploic veins
diploic veins are va
inner layer of skull bone that looks like a sponge
Frontal bone
forehead and superior rim of the orbit
- pneumatized bone (hollow) is superiro to each orbital rim
- glabella (area of skin between eyebrows above the nose) forms MEDIAL rim of orbit
- laterally the frontal bone extends with the frontal
Frontal Bone Articulations
joins parital bones through coronal suture
- greater wing of sphenoid
- frontal process of zygomatic bone
- through zygomatic process
- nasal and lacrimal bones
Parietal Bone
forms room and sides of the cranium
- composed of 2 SURFACES, 4 ANGLES, and 4 MARGINS
- angles: frontal, occipital, sagittal, squamous
- margins: frontal, sphenoid, mastoid, occipital
Occipital Bone
trapezoidal curved bone which overlies the occipital lobes
- 4 parts: squamous, basilar, 2 lateral parts than contain a large opening where the spinal cord passes (foramen magnum)
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Inner Occipital Surface
base of posterior cranial fossa, where the foramen magnum is bound
Exterior Occipital View
internal elements correspond to the outer surface
- 3 transversal nuchal lines
- 2 occipital condyles on each side of foramen magnum (articulate with the atlas)
Temporal Bone
paired flat bone on sides of cranium
- houses structures of ears
- 4 parts: squamous, zygomatic process, tympanic and styloid, petromastoid
Cranial Base
floor of cranial cavity
- 2 surfaces: endocranium and external cranial base
- sphenoid, ethmoid, occipital, frontal, temporal bone
Ethmoid Bone
small unpaired bone
- separates nasal from cranial cavity
- superior projection
- small portion of orbit
Sphenoid Bone
butterfly shaped unpaired bone
- anterior to basilar of occipital
- sphenoidal sinuses
- body, greater wings, lesser wings, ptygeroid
Viscerocranium
facial skeleton located ANTERIOR to neurocranium
- supports facial features
- 14 BONES
- joined through synarthroses except mandible (jaw moves)
Zygomatic Bone
irregular paired bone, form face lateral prominences (cheekbones)
- parts of orbit inferior and lateral rims
- 4 processes, 3 surfaces, 4 borders
Nasal Bone
small oblong paired bones
- forms nose bridge
- articulates medially through internasal suture
- each side has 2 surfaces, articulate frontal bone, inferiorly with maxillae
Maxillae
large paired bones, hold upper teeth
- formation or orbit, nasal cavity, and palate
- 4 processes: zygomatic, frontal, alveolar, palatine
Palatine Bone
irregular paired bones, alongside maxillae
- forms hard palate, between maxilla and pterygoid process
- fuse on midline, 2 perpendicular plates
