lecture 4 Flashcards
the skull
how many bones is the skull comprised of?
22 bones
how is the skull divided so that we can better understand it?
general regions, secondary cavities of the skull, cranial fossae, sutures
how is the general regions divided up?
neurocranium and viscerocranium
what is the neurocranium?
portion that encloses the brain
what is the viscerocranium?
the facial bones
what comprises the secondary cavities of the skull?
the nasal cavity, orbits, middle and inner ear, paranasal sinuses
what is the middle and inner ear responsible for?
houses structures for hearing and equilibrium
what are the paranasal sinuses?
mucosa lined hollows within bones that drain into nasal cavity
how is the paranasal sinuses named?
for bone in which they are found
what are the functions of the paranasal sinuses?
1) form mucus in which they are found
2) warm air
3) provide resonance for voice
what is sinusitis?
inflammation of a paranasal sinus due to allergy or infection which can lead to blockage of the ostium
what are the different types of sinusitis?
infection of ethmoid cells and maxillary sinuses
why is the infection of ethmoid cells important to note as sinusitis?
potential for infection to break through thin wall into medial orbit and this can cause blindness due to proximity to optic canal
how is the infection of ethmoid cells subdivided?
into anterior, middle, posterior ethmoid sinuses each with own ostia or opening
why is the infection of maxillary sinuses important to note as sinusitis?
because its the most common location of sinusitis
where can we see the infection of the maxillary sinus?
ostia superiorly located with head erect, drainage cannot occur until full; ostia medially directed resulting in nights rolling from side to side if both maxillary sinuses inflamed; close proximity to maxillary molars
where is the maxillary sinus perceived?
within molars
what happens if you fracture the molar and you invade the maxillary sinus during extraction?
opening would allow for infection, very little separation between tooth and sinus and when infection happens, it feels a lot like a tooth ache.
what is the transillumination of sinuses called?
it allows for direct observation of fluid, mucous or masses within the maxillary and frontal sinuses
what is the cranial fossae or flattened surface?
depressions in the cranium floor that contain various brain structures like the anterior, middle and posterior cranial fossae
what are the sutures?
immovable joints that hold bone of the skull together
what are the different types of sutures called?
coronal suture, sagittal suture, lambdoid suture, squamous suture
what is coronal suture?
unites frontal bone to parietal bone
what is sagittal suture?
unites parietal bones