Skull Anatomy Flashcards
How many bones make up the cranium?
8 bones
How many bones make up the facial area?
14 bones
What are the 8 cranium bones?
-Frontal (1)
-Ethmoid (1)
-Parietal (2)
-Sphenoid (1)
-Temporal (2)
-Occipital (1)
Cranial bones are joined together by articulations called?
sutures
The cranial bones create the protective housing for the _______.
brain
What are the 14 facial bones?
-Nasal bone (2)
-Lacrimal bone (2)
-Maxillae (2)
-Zygomatic bone (2)
-Palatine bone (2)
-Inferior nasal conchae or turbinates (2)
-Vomer (1)
-Mandible (1)
Facial bones are rigidly joined together by?
sutures
Facial bones are the protective housing for?
the upper end of the respiratory and digestive tracts
Facial bones for orbital sockets for?
the protection of the organs of sight
What is diploe?
Inner layer of spongy tissue which separates the two plates of compact tissue which compose the bones of the cranial vault
What is table?
outer plate; is thicker than the inner table over mostly of the vault and the thickness of the layer of spongy tissue varies considerably
What is meningeal grooves?
narrow, branchlike grooves which marks the internal surfaces of the bones
What is sulci?
large channels in the internal surfaces of the bones forming the vault of the cranium, which lodge blood vessels of various sizes
Where is the coronal suture found?
between the frontal and parietal bones
Where is the sagittal suture found?
between the two parietal bones and just behind the coronal suture line
Where is the squamosal suture located?
between the temporal bones and the parietal bones
Where is the lambdoidal suture located?
between the occipital bone and the parietal bones
Where is the pterion located?
at the junction of the parietal, temporal and the greater wing of the sphenoid bone
Where is the asterion located?
posterior to the ear where the squamosal and lambdoidal sutures meet
How many fontanels are there?
6 fontanels
What are the 6 fontanels?
-Anterior
-Posterior
-Sphenoid (2)
-Mastoid (2)
Where is the anterior fontanel?
at the junction of the coronal and sagittal sutures
Where is the posterior fontanel?
at the junction of the lambdoidal and sagittal sutures
Where are the sphenoid fontanels?
at the junction of the parietal, temporal and greater wing of the sphenoid
Where are the mastoid fontanels?
a point posterior to the ear where the squamosal and lambdoidal sutures meet
How many regions is the cranium divided into?
3
What are the 3 regions of the cranium?
-Anterior Cranial Fossa
-Middle Cranial Fossa
-Posterior Cranial Fossa
Where is the anterior cranial fossa?
extends form the anterior frontal bone to the lesser wings of the sphenoid
Where is the middle cranial fossa?
accommodates the temporal lobes and associated neurovascualar structures and extends from the lesser wings of the sphenoid bone to the apices of the petrous portions of the temporal bones
Where is the middle cranial fossa?
accommodates the temporal lobes and associated neurovascular structures and extends from the lesser wings of the sphenoid bone to the apices of the petrous portions of the temporal bones
Where is the posterior cranial fossa?
deep depression posterior tot he petrous ridges; protects the cerebellum, pons and medulla oblingata
What does the frontal bone form?
the forehead and the superior part of each orbit
What are the 2 parts of the frontal bone?
-Squamous or vertical portion
-Orbital or horizontal portion
What is in the squamous or vertical portion of the frontal bone?
-Glabella
-Supraorbital groove
-Supraorbital margin
-Supraorbital notch
-Frontal eminence (tuberosity)
-Superciliary arches
-Frontal air sinuses
What is the glabella?
the smooth prominence between the eyebrows and above the bridge of the nose
What is the supraorbital groove?
the depression above each eyebrow
What is the supraorbital margin?
the superior rim of each orbit
What is the supraorbital notch?
a small hole or opening within the supraorbital margin slightly medial to its midpoint. A nerve and artery pass through this small opening
What is the frontal eminence (tuberosity)?
a large rounded prominence located on each side of the median sagittal plane of the superior portion of the squama
What are the superciliary arches?
two arched ridges that correspond in position to the eyebrows located below the frontal eminences just above the supraorbital margins
What are the frontal air sinuses?
situated between the two tables of the squama on each side of the median sagittal plane, and from the lower margin of the squam they extend superiorly, laterally and posteriorly
What is included in the Orbital or horizontal portion of the frontal bone?
-Orbital plate
-Ethmoidal notch
-Nasal Spine
Where is the orbital plate?
on each side forms the superior part of each orbit
-the SOG is the external landmark at the level of the orbital plate
-below the orbital plates lie the facial bones and above the orbital plates is the anterior part of the floor of the brain case
Where is the ethmoidal notch?
separates each orbital plate from the other; the ethmoid bone fits into this notch
Where is the nasal spine?
round at the anterior end of the ethmoidal notch. This is a small inferior projection of bone which is the most superior component of the bony nasal septum
How many cranial bones does the frontal bone articulate with & what are they?
4; right and left parietals, sphenoid and ethmoid
What bones does the squama articulate with?
the parietal bones at the coronal suture, with the greater wing of the sphenoid bone at the frontosphenoid suture and with the nasal bone at the frontonasal suture
Where does the posterior margins of the orbital plates articulate?
with the lesser wings of the sphenoid bone
