Bones of the skull Flashcards
what is the skull? purpose?
bony structure support face and forms a protective cavity for brain
how does the skull form?
intramembranous ossification joined by sutures (fibrous joints)
what are the bones of the skull divided into?
2 groups:
cranium (can be subdivided)
face
what can the cranium be subdivided into?
skullcap = calvarium
cranial base
describe the cranium
also known as neurocranium
formed by superior aspect of skull
enclose and protects brain, meninges and cerebral vasculature
how can the cranium be subdivided anatomically?
into roof (Calvarium) and base
what does the calvirum consist of? (top of cranium)
frontal, occipital and 2 parietal bones
what does the cranial base consist of?
6 bones: FSEOPT
frontal, sphenoid, ethmoid, occipital, parietal and temporal bones
why is the cranial base important?
provide articulation point for 1st cervical vertebra (atlas), as well as facial bones and mandible (lower jaw bone)
what is the facial skeleton known as?
viscerocranium
what is the function of viscerocranium?
supports soft tissue of face - determines facial appearance
what does the viscerocranium consist of?
14 bones which fuse to house the:
orbits of the eyes,
nasal and oral cavities,
sinuses
what is the mnemonic for remembering the 14 facial bones?
Virgil Can Not Make My Pet Zebra Laugh
what are the 14 bones of viscerocranium? (facial bones)
Vomer 2 x inferior nasal Conchae 2 x Nasal 2 x Maxilla Mandible (jaw bone) 2 x Palatine 2 x Zygomatic 2 x Lacrimal
what do the 2 zygomatic form?
cheek bones of the face
articulates with the frontal, sphenoid, temporal and maxilla bones
where are the 2 Lacrimal bones?
smallest bones of the face
form part of medial wall of orbit
where are he 2 nasal bones?
3 slender bones
at bridge of nose
where are the 2 inferior nasal conchae bones?
located within the nasal cavity
function of inferior nasal conchae?
increase the SA of the nasal cavity
increasing the amount of inspired air that can come into contact with the cavity walls - warm + humid
where are the 2 palatine bones?
rear of oral cavity, forms part of hard palate
what does the maxilla bone comprise of?
part of the upper jaw and hard palate
what does the vomer bone form?
posterior aspect of nasal septum
what does the mandible (jaw bone) articulate with?
the base of the cranium at the temporomandibular joint (TMJ)
what are sutures?
a type of fibrous joint unique to the skull
immovable, fuse completely at around 20
why are sutures clinically important?
points of potential weakness in childhood and adulthood
what are the main sutures in adulthood?
CSL:
coronal suture
sagittal suture
lambdoid suture
what does coronal suture fuse?
fuses the frontal bone with 2 parietal bones
what does sagittal suture fuse?
both parietal bones to each other
what does lambdoid suture fuse?
fuses occipital bone to 2 parietal bones
how are sutures different in neonates?
the incompletely fused suture joints give rise to membranous gaps between bones
what are the membranous gaps between bones in neonates from incompletely fused suture joints called?
fontanelles
what are the major fontanelles in neonates?
frontal fontanelle
occipital fontanelle
where is the frontal fontanelle?
located at the junction of the coronal and sagittal sutures
where is the occipital fontanelle?
located at junction of sagittal and lambdoid sutures
