Skull & Cranial Cavity

Question 1

What are the 5 layers of the SCALP?

Answer 1

Skin
Connective tissue
Aponeurotic layer 
Loose connective tissue 
Pericranium

Question 2

What is the innervation of the scalp?

Answer 2

Trigeminal nerve (CN 5) and spinal cutaneous nerves

Question 3

Name the 8 neurocranial bones

Answer 3

Occipital 
2 Temporal
2 Parietal 
Sphenoid 
Ethmoid 
Frontal

Question 4

Name the 14 viscerocranium bones

Answer 4

2 nasal conchae 
2 nasal bones 
2 maxilla 
2 plantine 
2 zygomatic 
2 lacrimal 
vomer 
mandible

Question 5

Name the 3 layers of the meninges

Answer 5

Dura Mater
Arachnoid Mater
Pia Mater

Question 6

What are the 2 layers of the dura mater?

Answer 6

Endosteal layer- stuck to skull, lines skull only, stops at magnum foramen
Meningeal layer- around brain and spinal cord
layers are closely applied unless forming a dural sinus

Question 7

Nerve supply of dura mater?

Answer 7

CN 5, 10
C1-3
Sympathetic

Question 8

Blood supply of dura mater?

Answer 8

Middle meningeal artery

Question 9

What is the function of the meningeal layer of the dura?

Answer 9

Creates series of folds/septa dividing the cranial cavity, prevents/restricts movement.

Question 10

What does the Falx Cerebri separate?

Answer 10

Cerebral hemispheres

Question 11

What does the Tentori Cerebelli separate?

Answer 11

Cerebral hemispheres from cerebellar hemispheres

Question 12

What does the Falx Cerebelli separate?

Answer 12

Cerebellar hemispheres

Question 13

What are 3 clinical applications of the dura mater?

Answer 13

Dura stretching is anatomical basis of headache
Damage to middle meningeal artery - extradural haematoma
Tentorial herniation- caused by space occupying lesion causing herniation of the temporal lobe

Question 14

Describe the arachnoid mater

Answer 14

Middle layer of meninges
Loosely applied
avascular
All structures passing to/from brain pass through subarachnoid space

Question 15

What meninges contains the CSF?

Answer 15

The arachnoid mater within the subarachnoid space

Question 16

What produces CSF?

Answer 16

Choroid plexus in the brain ventricles - around 500ml produced per day

Question 17

What is the function of CSF?

Answer 17

Provides buoyancy to brain protecting it from mechanical forces

Question 18

What is the function of arachnoid granulations?

Answer 18

To affect the transfer of CSF to the venous sinuses to prevent buildup of CSF in subarachnoid space

Question 19

Describe the Pia mater

Answer 19

Innermost layer of meninges
delicate vascular membrane
close to brain following gyri and sulci
cerebral arteries enter brain carrying sheath of pia mater with them to create periarterial space

Question 20

what are the 3 layers of the spinal cord meninges and how does this differ to the brain?

Answer 20

1. dura mater- with meningeal layer only
2. arachnoid mater
3. pia mater

Question 21

What is leptomeningitis?

Answer 21

Infection and inflammation in arachnoid and pia maters. May enter subarachnoid space and enter blood causing septicaemia

Question 22

What are dural sinuses?

Answer 22

spaces created by layers of dura mater. Drain blood and CSF via cerebral veins.

Question 23

Where do the dural sinuses drain into?

Answer 23

Jugular vein

Question 24

What are the features of dural sinuses?

Answer 24

Thick walled endothelium
No valves
No smooth muscle

Question 25

What are the 2 main arteries supplying blood to the brain?

Answer 25

Internal carotid artery | Vertebral artery

Question 26

What are the 2 terminal branches inside the skull?

Answer 26

Anterior cerebral artery | Middle cerebral artery

Question 27

Which artery do the vertebral arteries unite to form?

Answer 27

Basilar artery

Question 28

What is the cerebral arterial circle formed from?

Answer 28

Anastomosis between 2 internal carotid arteries and 2 vertebral arteries

Question 29

What areas of the brain do the cerebral arteries supply?

Answer 29

Anterior cerebral artery: medial and superior surfaces & frontal pole Middle cerebral artery: lateral surfaces and temporal pole Posterior cerebral artery: inferior surfaces and occipital pole

Question 30

What causes a stroke and why?

Answer 30

Embolism in a cerebral artery because there is no anastomosis of cerebral arteries once inside the brain so causes neurological deficit

Question 31

When does mixing in posterior communicating artery occur?

Answer 31

Only when ICA or vertebral artery is occluded- in this case blood passes back and forth across the PCA to compensate for reduced blood flow

Question 32

Which cranial nerves pass through the cribiform plate

Answer 32

CN 1

Question 33

Which cranial nerves pass through the optic canal?

Answer 33

CN 2, Opthalmic A

Question 34

Which cranial nerves pass through the superior orbital fissure?

Answer 34

CN 3,4,6,5 V1

Question 35

Which cranial nerves pass through rotundum

Answer 35

CN 5 V2

Question 36

Which cranial nerves pass through ovale?

Answer 36

CN 5 V3

Question 37

Which structures pass through spinosum?

Answer 37

Middle meningeal artery

Question 38

Which structures pass through lacerum?

Answer 38

Carotid artery traverses it (doesn't pass through)

Question 39

Which cranial nerves pass through internal acoustic meatus?

Answer 39

CN 7 and 8

Question 40

Which cranial nerves pass through jugular foramen?

Answer 40

CN 9,10,11, IJV

Question 41

Which cranial nerves pass through hypoglossal canal?

Answer 41

CN12

Question 42

Which structure passes through the foramen magnum?

Answer 42

Spinal cord