Skull Anatomy Flashcards
how many bones are in the skull
22
how are the bones in the skull joined together
- 21 are linked by fibrous joints – the mandible articulates via the synovial temporomandibular joint
what is the role of the neurocranium
- this is the cranial vault
Role - Protect the fragile brain
- Attachment site for head and neck muscles
what is the role of the viscerocranium
this is the facial skeleton Role • Form framework of the face • Contain cavities for special sense organs (sight, taste and smell) • Opening for air and food passage • Secure teeth • Anchor facial muscles of expression
How many cranial bones are there
There are 8 cranial bones
what are the 8 cranial bones
- Parietal (x2)
- Temporal (x2)
- Sphenoid
- Frontal
- Ethmoid – CSF leaks in if it is damaged
- Occipital
what are the sutures in the cranium
- Sagittal suture – between two parietal bones
- Coronal suture – between frontal and parietal bones
- Lambdoid suture
- Squamous suture
what is the pterion
it is where the frontal, parietal, temporal and sphenoid all join
- it is the weak part of the skull
what part of the ear does the temporal bone have in it
- The temporal bone has both the middle and internal ear in it,
describe the structure of the temporal bone
- Superior part is called the squamous part
- The internal aspect of the temporal bone (bony shelf) is called the petrous part of the temporally bone
- Externally projecting anteriorly is the zygomatic process
- And inferior is the mastoid process
- Styloid process is just anterior
- And anterior to the styloid process is the external acoustic meatus
where is all of the inner ear housed
all of the inner ear is housed between the petrous part of the temporal bone
what is the sphenoid bone
- This is the bone that links the facial skeleton to the cranial skeleton
what can fractures of the sphenoid bone do
- separate the cranial and facial skeleton
what is the part of the sphenoid bone where the muscles attach
- Pterygoid plate – this is where the muscles of mastication attach to
describe the structure of the sphenoid bone
- The greater wing makes the external edge of the skull whereas the lesser wing makes up the internal aspect of the skull
- Pterygoid plate – this is where the muscles of mastication attach to
- There is a sella turnica – this is the depression, it is a bony cradle that protects the pituitary gland
- Either side of the sella turica there is the anterior clinoid process and posterior clinoid process
what are the 3 meninges in the brain
- Dura mater, arachnoid mater, and pia mater
how many layers of the dura mater are there in the skull
2
what are the two layers of the dura mater in the skull
periosteal and meningeal layer
what does the periosteal layer of the dura mater do
it attaches to the skull itself
what does the meningeal layer of the dura mater do
at certan points pulls always from the inside of the skull it forms inwards folds
what separates the cerebellum form the brain
- Flax cerebri and tentorium cerebellum separates the cerebellum from the brain above
- Compartmentalises the brain and gives support to the brain
what structure allows the brainstem to pass up into the brain
- Compartmentalises the brain and gives support to the brain
- The tentorial notch allows the brainstem to pass up the brain
what is between the periosteal and meningeal layers of the dura mater
- Between the periosteal and meningeal layers of the dura mater is a network of endothelial lined spaces, which are filled with venous blood; the dural venous sinuses.
what are the different types of dural venous sinuses
- Superior sagittal sinus and inferior sagittal sinus
- Transverse and straight and sigmoid and periosteal and cavernous sinuses
How does the dural venous sinuses drain
- The sigmoid sinus is continuous with the jugular vein which goes through the jugular foramen
- Also have a cavernous sinus this is clinically important, this is because the internal carotid artery runs straight through it, there is also a petrosal sinus