Anatomy Flashcards
(207 cards)
What are the two groups of skull bones?
Cranium and facial bones
Describe the layers of the cranial bones
an external and an internal layer of compact bone, with spongy bone (diploe bone) inbetween
What are the four sutures of the cranium?
coronal suture anteriorly
sagittal suture in the midline
lambdoid suture between parietal and occipital (coronal as well)
pterion suture
What is the pterion suture bound by?
frontal bone supero-anterior
sphenoid bone infero-anterior
parietal bone supero-posterior
temporal bone infero-posterior
Which artery lies under the pterion suture?
middle meningeal artery
What are the two parts of frontal bone? and what is name of the junction between the two parts?
vertical part forming the forehead
horizontal part forming the roof of the orbits
superior orbital margin
T/F is the parietal bone completely flat?
No, it is mostly flat, but moulds to the shape of the brain
What is one prominent landmark of occipital bone
external occipital protuberance
What are the five parts of the temporal bone
1) flat squamous part
2) anterior projection, the zygomatic process
3) posterior projection, the mastoid process
4) styloid process inferiorly
5) petrous part, inward projection
Where does a depressed fracture of the cheek occur?
at the zygomatic process of the temporal bone
What is special about the mastoid process?
it is thick and full of air space
What is special about the styloid process?
gives attachment for muscles of the oral cavity and the pharynx
Sphenoid bone looks like a bat. What are the 3 major parts?
body, lesser wing antero-superiorly, greater wing inferior to lesser wing
What is found in the body of sphenoid bone, where there is a depression?
the pituitary gland
Not very relevant - body of the sphenoid is also known as?
Sella turcica
What divides the greater and lesser wings
superior orbital fissure
What are the characteristics of the two major parts of ethmoid bone in the cranial floor?
1) cribiform plate: with little holes for olfactory nerve fibres
2) crista galli, the middle segment that pokes up
What is within the
1) anterior cranial fossa
2) middle cranial fossa
3) posterior cranial fossa
1) horizontal plate of frontal bone, cribiform plate of ethmoid, lesser wing
2) greater wing, petrous part of temporal, with the wedge forming boundary to posterior cranial fossa
3) occipital bone
which cranial fossa is superior orbital fissure found?
middle
What is special about superior orbital fissure
it provides direct communication between orbit to cranial cavity
Superior orbital fissure is the beginning of an arch of foramina. What are the foraminae?
foramen rotundum, foramen ovale, foramen spinosum
Where is the optic canal?
medial to the superior orbital fissure, in the lateral body of the sphenoid
Where is foramen lacerum? What goes through the foramen?
at the medial junction between greater wing and petrous wedge. Medial to both foramen ovale and spinosum
Nothing goes through. It is covered by a membrane when meninges is intact
There are three foramens in the petrous wedge of posterior cranial fossa, what are they?
internal auditory meatus, jugular foramen inferior to the meatus, and hypoglossal foramen medial to jugular foramen