Session 2 Head & Neck

Question 1

What are the bones of the neurocranium?

Answer 1

Neurocranium :
Ethmoid, sphenoid, parietal (2) occipital, temporal (2) , frontal

Seperate into the calvaria (the upper region) and the cranial floor

Question 2

What are the bones of the viscerocranium ?

Answer 2

Zygomatic (2) lacrimal (2) nasal (2) inferior nasal concha (2) vomer, maxilla (2) mandible, palatine.

Question 3

How many layers of bone are there in the calvaria and why is this important ?

Answer 3

There are three layers called the dilpoe.
Outer compact, inner spongey and outer compact.
This confers a protective role for the brain without adding significant weight to the brain.

Question 4

What are the signs of a basilar fracture ?

Answer 4

Racoons eyes - bruising around the eyes
Haemotympanum- bleeding in the ear, (behind the ear drum)
Bruising on the mastoid process
Rhinorrhea or ottorhea ( CSF leakage - or even blood etc)

Question 5

How many cranial sutures are there, where are they located?

Answer 5

Coronal suture - frontal and parietal bone
Sagital suture - parietal and parietal
Lamboidal suture - parietal and occipital

Squamous suture - (squamous) temporal and the parietal , this extends from the pterion,

Question 6

Why is it important the flat bones of the skull have an interlocking nature?

Answer 6

This is so that the bones do not slide over each other it maintains them (protective role) this makes it more difficult to dislocate.

Question 7

What is the weakest part of the skull?

Answer 7

Pterion, the lateral aspect of the skull
Temporal, parietal and sphenoid form this region.

Directly below this is the middle meningeal artery which supplies blood to the dura.

Question 8

When you injure the pterion what are you at risk of?

Answer 8

Extra dural haemorrhage .
This is between the Dura and the periosteum . Blood will accumulate in this layer and will raise intercranial pressure and could damage the brain.

Question 9

Where are the soft spots in a newborn and why are they there?

Answer 9

Anterior fontanelle - region of unfused bone , membranous region of the skull. This is where the coronal and sagital suture meet.

Posterior fontanelle - where the sagital and lamboidal suture meet.

Function: ease birthing and also to allow the brain to grow.
They should ossify by 2.

Question 10

What is the significance of a sunken soft spot?

Answer 10

Indicates malnutrition or dehydration

Question 11

What is the significance of a enlarged or bulging fontanelle?

Answer 11

This could be due to bleeding, rise in intercranial pressure secondary to meningitis, enkephalitis.
It could also be due to premature birth , or other Congential syndromes (rubella)

Question 12

When you suspect a skull fracture what imaging modalitiy should be used ?

Answer 12

CT this is as the key thing is to asses if there is a Brain injury.

Question 13

What are the complications of a basilar fracture ?

Answer 13

Meningitis -there is a route for bacteria to travel directly to the Meninges.
Cranial nerve palsy (often the facial nerve)
Meningeal tears can lead to leakage of CSF and also bleeding of the sot tissues, sinuses and the tympanic cavity.

Question 14

What runs in the foramen spinosum?

Answer 14

The middle meningeal artery

Question 15

What runs in the foramen rotundum?

Answer 15

It runs downwards and laterally in an oblique path and joins the middle cranial fossa with the pterygopalatine fossa. It transmits maxillary nerve branch (V2) of trigeminal nerve, artery of foramen rotundum and emissary veins.

Question 16

What is in the internal acoustic meatus?

Answer 16

This is a canal within the petrous part of the temporal bone of the skull between the posterior cranial fossa and the inner ear.

Vestibulocochlear nerve
Facial nerve
Vetribular ganglion
Labyrinthe artery

Question 17

What runs in the carotid canal?

Answer 17

The carotid canal is the passageway in the temporal bone through which the internal carotid artery enters the middle cranial fossa from the neck. The canal starts on the inferior surface of the temporal bone at the external opening of the carotid canal

Question 18

What runs in the foramen ovale?

Answer 18

The following structures pass through foramen ovale: Mandibular nerve.
Motor root of the trigeminal nerve.
Accessory meningeal artery (small meningeal or paradural branch, sometimes derived from the middle meningeal artery)

Question 19

What runs in the foramen magnum?

Answer 19

medulla oblongta
vertebral arteries
the anterior and posterior spinal arteries
the tectorial membranes & alar ligaments.
spinal component of the accessory nerve into the skull.

Question 20

What runs in the jugular foramen.?

Answer 20

Cranial nerves IX, X, and XI and the internal jugular vein pass through the jugular foramen.

Question 21

What runs in the hypoglossal canal ?

Answer 21

Hypoglossal cranial nerve

Question 22

What is the facial skeleton a derivative of?

Answer 22

Frontonasal prominence