skull

Question 1

What is the plane called to ensure skulls are in the same orientation? What are the 3 points that define this?

Answer 1

•The Frankfurt Horizontal (FH) plane

• Right and left porion points (located at top of each external acoustic meatus)
• Left orbitale (located at bottom of left orbit)

Question 2

What are the 5 different perspectives FH skulls can be viewed from?

Answer 2

Norma verticalis (from above) Norma lateralis (from side) Norma occipitalis (from behind) Norma frontalis (from front) Norma basilaris (from below)

Question 3

What do sutures act as?

Answer 3

Sutures act as crack stoppers to prevent fractures from spreading through the whole skull

Question 4

What do primary cartilaginous joints facilitate and where are they found?

Answer 4

Primary cartilaginous joints found on base of skull facilitates growth of base of skull

Question 5

What do sutures do?

Answer 5

Sutures act as crack stoppers to prevent fractures from spreading through the whole skull

Question 6

What 2 sections can the skull be divided into?

Answer 6

Neurocranium and Viscerocranium

•Neurocranium – consists of a base and a vault

–supports & protects the brain

•Viscerocranium (part of the skull that forms the face) – the upper part forms the orbits and nose, and the lower part, together with the mandible, constitutes the jaws

–concerned with breathing and eating

–consists of most of face, hyoid and larynx

Question 7

What can the Neurocranium divide into?

Answer 7

Membranous Neurocranium

(sometimes known as Dermatocranium)

(superior/upper part)

•Flat bones of skull cap

(eg frontal, parietal )

• Formed by intramembranous ossification formed from mesenchyme.
• Membrane bone more protective

and

Cartilaginous Neurocranium

(brain rests on this)

•Bones of base of skull

eg ethmoid, sphenoid

• Formed by endochondral ossification arisesed by a cartilaginous template
• Endochondral bone more supportive

Question 8

Name all the bones of the skull.

Answer 8

FRONTAL (1)

PARIETAL (2)

TEMPORAL (2)

OCCIPITAL (1)

SPHENOID (1)

ZYGOMATIC (2)

MAXILLA (2)

NASAL (2)

PALATINE (2)

ETHMOID (1)

Inf. NASAL CONCHA (2)

LACRIMAL (2)

VOMER (1)

MANDIBLE (1)

HYOID (1)

Question 9

What are the flat bones of the dermatocranium are made up of?

what is the interspace between them called?

Answer 9

• The flat bones of the dermatocranium are made from an outer and an inner plate of thin compact bone.
• Interspersed between these layers of compact bone is the diploe

Question 10

What do the membrane bones of the dermatocranium contain?

Answer 10

•The membrane bones of the dermatocranium contain diploe that confers lightness and strength as well as some flexibility

Question 11

The maxilla is a light bone with THREE strengthened areas through which the forces are channelled to the whole skull. What are these areas?

Answer 11

•The strengthened parts are called CRANIO-FACIAL BUTTRESSES.

–Frontonasal,

–Zygomatic

–Pterygoid