The Skull Flashcards
Functions of the skull?
Enclose and protect brain and special sense organs Create a specialised environment in which the brain can thrive (cranial cavity) Attachment of muscle and meninges
What are the three layers of the bones in the cranium?
Outer plate -compact bone
Diploe-Spongy bone (reduces the weight)
Inner plate - compact bone
Which bones form the cap of the cranium?
Frontal Parietal Occipital Temporal
What grooves does the parietal bone have?
Grooves of: -middle meaningeal artery -sagittal sulcus -granular pits -sigmoid sulcus
What are the four parts of the occipital bone arranged around?
Foramen magnum
Which bones form the floor of the calvaria? (Aka cranial fossa, cranial base)
Sphenoidal Ethmoid Temporal
Features of the sphenoid bone?
Has the sphenoid sinus Greater and lesser wings Pterygoid process Optic groove
What can fracture of the ethmoid bone lead to?
Anosmia (loss of sense of smell)
Features of the temporal bone?
Zygomatic process, squamous, External auditory meatus(tympanic) , mastiod process, Madibular fossa (articulate with TMJ), articular tubular, Styloid process, styliod mastoid foramen,
What do the bones of the cranial base provide articulation for?
C1 (atlas) Facial bones Mandible
Name the bones of the facial skeleton
Zygomatic Lacrimal Nasal Inferior nasal conchae Palatine Vomer Maxillae Mandible Frontal
What are the main sutures in adulthood?
Coronal suture - between frontal and parietals Saggital - between both parietals Lambdoid - occipital with parietals Visualise it!
What are fontanelles?
Incompletely fused suture joints in neonates
Which bones form each of the cranial fossas?
Anterior - depression formed by frontal, ethmoidal and parietal Middle - depression formed by sphenoid, temporal, parietal Posterior - squamous, mastoid temporal bone, occipital bone
What makes the bones of the skull less easily unlocked?
The edges are serrated
Which bones are most frequently broken in a facial fracture?
Nasal
Frontal Bone
the large cranial bone forming the front part of the cranium: the forehead and the upper part of the orbits
Frontal sinus
one of a pair of cavities in the frontal bone
Glabella
The smooth area between the eyebrows just above the nose
Supraorbital Foramen
small opening superior to each eye socket
Parietal Bone
either of two skull bones between the frontal and occipital bones and forming the top and sides of the cranium
Temporal Bone
a thick bone forming the side of the human cranium and encasing the inner ear
Mastoid Process
process of the temporal bone behind the ear at the base of the skull
Mandibular Fossa
the depression in the temporal bone into which the condyle of the mandible fits.
Zygomatic Process
part of the temporal bone that forms part of the cheekbone
Styloid Process
pole like process extending downward from the temporal bone on each side of the skull
Internal Acoustic Meatus
a canal in the petrous part of the temporal bone of the skull
Foramen Magnum
the large opening at the base of the cranium through which the spinal cord passes
Occipital Bone
the bone found at the back and base of the skull
Occipital Condyles
rounded projections lateral to the foramen magnum that articulate with the first cervical vertebra (atlas)
midline prominences posterior to the foramen magnum
External Occipital Protuberance
Ethmoid Bone
irregularly shaped bone anterior to the sphenoid. Forms the roof and upper septum of the nasal cavity and part of the medial orbit walls.
Crista Galli
superior projection in the middle of the cribriform plate of the ethmoid bone
Cribriform Plate
porous bone surrounding the crista galli in the floor of the cranium through which olfactory nerves transverse
Sagittal Suture
midline articulation point of the two parietal bones
Coronal Suture
the suture between the parietal and frontal bones of the skull
Squamousal Suture
the suture found between the parietal & temporal bone
suture that separates parietal bones from occipital bone
Lambdoidal Suture
the suture between the two ossification centers of the frontal bone, it usually disappears during development but is occasionally present in adults
Metopic Suture
