SurgSoc

Question 1

What are the different tissue layers of the scalp?

Answer 1

Skin 
Connective Tissue
Aponeurosis
Loose Areolar Tissue 
Periosteum

Question 2

Where is the tentorium cerebelli?

Answer 2

The tentorium cerebelli dural fold exists between the:

• Occipital lobes
• Cerebellum and brainstem

Question 3

Describe the formation and drainage of CSF

Answer 3

• The choroid plexi create CSF in each ventricle.
• laterals drain into third ventricle through the interventricular foramina
• into fourth ventricle via the cerebral aqueduct
• Then into the subarachnoid space
• From the subarachnoid space, the CSF will drain into the dural venous sinuses via arachnoid granulations

Question 4

At what vertebral level does the common carotid split into the internal and external carotids?

Answer 4

C4 - the level of the laryngeal prominence

Question 5

What are the branches of the internal carotid artery when it first divides the cranial cavity?

Answer 5

• (Ophthalmic branch)
• Anterior cerebral artery
• Middle cerebral artery
• (Posterior communicating artery)

Question 6

Where do the vertebral arteries arise from?

Answer 6

come off the 1st part of the subclavian arteries

Question 7

State the branches of the vertebral arteries (before it forms the basilar artery)

Answer 7

• Anterior spinal (1) – supplies anterior 2/3 of the spinal cord
• Posterior spinal (2) – supplies posterior 1/3 of spinal cord
  (- Posterior Inferior Cerebellar Artery – supplies the posterior inferior aspect of cerebellum)

Question 8

Give the branches of the basilar artery

Answer 8

• (Anterior inferior cerebellar arteries)
• Pontine arteries – several small branches
• (Labyrinthine arteries)
• (Superior cerebellar arteries)
• Posterior cerebral arteries

Question 9

What are dural venous sinuses?

Answer 9

endothelial lined spaces between the outer periosteal and inner meningeal layers of dura mater

Question 10

Where is the faxl cerebri?

Answer 10

The falx cerebri exists within the longitudinal cerebral fissure and thus exists between:

• The left hemisphere
• The right hemisphere

Question 11

What are emissary veins?

Answer 11

Emissary veins conduct blood from outside the cranium, into the venous sinuses

Question 12

Which of the structures sunning through the cavernous sinuses are at the medial and lateral borders?

Answer 12

Medial border:
- Internal carotid artery
- Abducens nerve (VI)
This lies alongside the artery and therefore is susceptible to damage
Lateral border:
- CN III
- CN IV
- CN V1
- CN V2

Question 13

What is the concern with regards to the cavernous sinus and

Answer 13

The emissary veins can act as a conduit for extracranial infections to reach intracranial areas
If emissary veins reach the cavernous sinus, this can lead to complications, especially as multiple nerves and the internal carotid artery run through it.

Clinical Significance – Cavernous Sinus Thrombosis (clot within the cavernous sinus)
Most common cause is infection; which typically spreads from an extracranial location.
The abducens nerve (CN VI) is most commonly affected.
Where the cause is infection, thrombosis of the cavernous sinus can rapidly progress to meningitis.