Skull Overview and Applied Anatomy of Face and Jaws Flashcards
What plane is used to compare skulls?
Frankfurt horizontal (FH) plane
What 3 points define the Frankfurt horizontal plane?
- Right and left porion points (located at top of each external acoustic meatus)
- Left orbitale (located at bottom of left orbit)
Using FH, skulls are viewed from 5 standard perspectives. What are these perspectives?
- Norma verticalis (from above)
- Norma lateralis (from side)
- Norma occipitalis (from behind)
- Norma frontalis (from front)
- Norma basilaris (from below)
What gives the skull its strength despite being lightweight?
It’s large number of bones.
how many bones does the skull have at least?
23 (including the hyoid)
What does the large number of bones in the skull also contribute to?
It’s versatility.
What are the 3 benefits of having more joints between bones in the skull?
- More joints between bones enables babies with bigger heads to be born.
- More joints facilitate complex growth patterns.
- More joints increase the resilience of the structure and so reduces the danger of fractures assuming catastrophic proportions.
What is the role of the skull?
To support and protect the brain and organs of special sense as well as housing the first part of the respiratory and alimentary tracts.
The skull can be divided into 2 parts, what are these 2 parts?
- The neurocranium (braincase)
2. The viscerocranium
What does the neurocranium consist of?
- A base
- A vault whose side walls and roof (calvaria) complete the bony covering
What is the role of the neurocranium
To support & protect the brain
What does the viscerocranium consist of?
- Consists of most of face, hyoid and larynx
- The upper part forms the orbits and nose
- The lower part, together with the mandible, constitutes the jaws
What is the role of the viscerocranium?
Aids breathing and eating
What are the 2 types of Neurocranium?
- Membranous neurocranium
2. Cartilaginous neurocranium
What is the membranous neurocranium also known as?
Dermatocranium
What is the cartilaginous neurocranium also known as?
Chondrocranium
What makes up the membranous neurocranium?
The flat bones of skull cap
eg frontal, parietal
What makes up the cartilaginous neurocranium?
The bones of base of skull
eg ethmoid, sphenoid