Session 2

Question 1

Which suture can be found between the parietal bones?

Answer 1

Sagittal Suture

Question 2

Which suture can be found between the frontal bone and parietal bones?

Answer 2

Coronal Suture

Question 3

What suture can be found between the occipital bone and parietal bone?

Answer 3

Lambdoid suture

Question 4

Which 2 groups can the bones of the skull be broadly divided into?

Answer 4

Neurocranium - 8 bones

• Encase and protect brain
• Has the Calvaria, Cranial floor base and Cranial cavity

Viscercranium - 14 bones

• Facial skeleton and the jaw
• Surround the oral cavity, pharynx and upper respiratory passages

Question 5

What does the Calvaria begin as and how does it ossify?

Answer 5

Begins as membrane and undergoes intramembranous ossification

Question 6

What does the floor of the neurocranium begin as and by which process does it ossify?

Answer 6

• Cartilage

- Undergoes endochondrial ossification

Question 7

How do structures within neurocranium communicate with other head and neck structures?

Answer 7

• Cranial floor has holes that enable cranial nerves to allow communication between the brain and brain stem and the structures of the face and neck they innervate.
• Blood vessels also pass between these holes

Question 8

What are the 3 bowl shaped depression formed on the cranial floor?

Answer 8

• Anterior Cranial Fossae
• Middle Cranial Fossae
• Posterior Cranial Fossae

Question 9

What is the trilaminar arrangement of the calvaria?

Answer 9

Outer Table (compact bone)
Diploeic Cavity (spongy bone)
Inner table (compact bone)

Question 10

Why are the edges of the bones of the skull serrated?

Answer 10

To prevent slippage and movement

Question 11

When does growth at sutures stop?

Answer 11

Puberty

Question 12

What covers the surface of the outer table of bone?

Answer 12

Periosteum

-Strongly adhered at suture line

Question 13

Periosteum covering the outer table is continuous through to the periosteum covering the inner table. True/False

Answer 13

True

Question 14

Where does a cephalohaematoma occur?

Answer 14

Occurs between he periosteum and the bones.

Question 15

Can bleeding in a cephalohaematoma pass the suture lines?

Answer 15

No it cannot.

Question 16

What are fontanelles?

Answer 16

Areas of membrane between bones that are particularly large.

Question 17

What are the purposes of fontanelles?

Answer 17

• To allow for altering of the skull size and shape during child birth
• To permit growth of infant brain

Question 18

When the fontanelles fuse?

Answer 18

Posterior - 1 month to 3 months

Anterior - 18 months to 2 years

Question 19

What is early fusion of fontanelles and sutures called?

Answer 19

Craniosyntosis

Question 20

What is the shape of the fontanelles?

Answer 20

Slightly convex shape in a healthy baby

Question 21

What should be performed in all partients with known or suspected skull fractures?

Answer 21

CT scanning should be performed to identify intra cranial injuries

Question 22

What are the two main types of fractures?

Answer 22

Linear - pass full thickness of skull. It is failed strains and involve no bone displacement

Depressed - Fragment is displaced inwards towards the brain

Question 23

What are basilar skull fractures and what are their risks?

Answer 23

Fractures involving the cranial base

• Associated with cranial nerve injuries
• Prone to causing cerebrospinal fluid leaks

Question 24

Which artery is underlying the Pterion?

Answer 24

Middle meningeal artery

Question 25

Why is the pterion particularly at risk of fracture?

Answer 25

It is the thinnest area of the skull

Question 26

What is the risk with the pterion?

Answer 26

Intracranial Haemorrhage due to the injury to the middle meningeal artery

Question 27

What are some signs of basilar skull fractures?

Answer 27

- Raccoon eyes - Battle signs - Hemotympanum

Question 28

What the 3 sacs around the brain and their properties?

Answer 28

Dura: tough fibrous membrane Arachnoid: soft translucent membrane Pia: microscopically thin, delicate and closely adherent to surface of brain

Question 29

Which membranous layers of the brain can be pulled away easily?

Answer 29

Dura and Arachanoid

Question 30

The dura is translucent. True/False

Answer 30

False. The arachnoid is translucent

Question 31

What are the layers of the dura?

Answer 31

``` Periosteal = endosteum lining the inner bones of skull Meningeal = Layers adjacent to arachnoid ```

Question 32

What is formed by separation of the two layers of the dura?

Answer 32

- Dural folds | - Dural venous sinuses

Question 33

What is the purpose of the dural folds?

Answer 33

Helps to stabilise the brain and act as Rigid dividers

Question 34

What are these signs associated with? A. Sunken fontanelles B. Bulging fontanelles C. Enlarged fontanelles

Answer 34

A. Sign of dehydration B. Symptom of serious illness such as meningitits C. Sign of Down syndrome or premature birth

Question 35

Where can the falx cerebri be found?

Answer 35

In the sagittal place. It lies in the midline of the brain

Question 36

Where can the tentorium cerebella be found?

Answer 36

In the transverse plane of the brain. It slips between the cerebellum and the brain.

Question 37

What can a rise in pressure inside the skull lead to?

Answer 37

Compression and displacement of the brain against the rigid folds and/or through foramen magnum. (herniation)

Question 38

What are the effect of a rise in pressure on the cranial nerves?

Answer 38

Their roots have a close relationship with the dural folds so they can get squashed

Question 39

What are dural venous sinuses?

Answer 39

Venous blood filled spaces created by separation of meningeal from periosteal layer of the dura.

Question 40

Where do the major venous sinuses lie?

Answer 40

At the border of the falx cerebri, falx cerebelli and also on the cranial floor.

Question 41

Where does venous blood from the brain drain to?

Answer 41

Venous sinuses via the cerebral veins

Question 42

Where do the dural venous sinuses eventually drain to?

Answer 42

Internal jugular vein

Question 43

Which venous sinus runs in the sagittal plane?

Answer 43

- Superior sagital sinus | - Inferior sagital sinus

Question 44

Which venous sinus runs in the transverse plane?

Answer 44

-Transverse venous sinus

Question 45

What does the transverse venous sinus change to when it reaches the petrous bone?

Answer 45

Sigmoid sinus

Question 46

When does the sigmoid sinus become the internal jugular vein?

Answer 46

When it reaches the jugular foramen

Question 47

Where is the confluence of sinuses found?

Answer 47

Deep to the protuberance of the occipital bone

Question 48

What is the confluence of sinuses?

Answer 48

A meeting point of the straight sinus, superior sagittal sinus and inferior sagittal sinus.

Question 49

How do cerebral veins within the subarachnoid space drain into the dural venous sinuses?

Answer 49

Bridging veins

Question 50

What is a common cause of extradural haemorrhage?

Answer 50

Arterial bleed via the middle meningeal artery. Bleeding occurs between the bone and periosteal

Question 51

What is a common cause of subdural haemorrhage?

Answer 51

Venous bleed through the bridging veins.

Question 52

Why doesn't the bleed form a subdural haemorrhage spread across the brain?

Answer 52

Falx cerebri stops the spread across the side of the brain

Question 53

Why are older people more susceptible to subdural haemorrhage?

Answer 53

- The Brian gets smaller as you get older - Increase tension of the bridging veins - A slight knock could cause the veins to rupture as a result

Question 54

What usually cause a subarachnoid haemorrhage?

Answer 54

-Usually a branch of the circle of willis Secondary to trauma or spontansous rupture of the blood vessel