Cranium, meninges and brain

Question 1

How many bones make up the skull?

Answer 1

22

Question 2

Recall the 9 main bones of the skull

Answer 2

Frontal
Parietal
Temporal
Parietal
Zygoma
Ethmoid
Mandible
Maxilla
Occipital

Question 3

What bone forms the roof of the mouth?

Answer 3

Palatine

Question 4

What bone is seen to split the 2 halves of the nose?

Answer 4

Vomer

Question 5

What foramina are found in the maxilla?

Answer 5

Intraorbital

Question 6

Recall the 3 main sutures of the skull

Answer 6

Coronal
Saggital
Lamboid

Question 7

What name is given to the protrusion at the most dorsal point of the occipital bone?

Answer 7

Inion (external occipital protuberance)

Question 8

What name is given to the “soft spots” in the infant skull?

Answer 8

Fontanelles

Question 9

What is the internal capsule?

Answer 9

Fibrous tract where fibres from the cortex come together

Question 10

Recall the layers of the scalp, from superficial to deep

Answer 10

Skin
Connective tissue
Aponeurosis
Loose areolar tissue
Periosteum

Question 11

Within which layer of the scalp are arteries, veins and nerves found?

Answer 11

Connective tissue

Question 12

Which muscle’s aponeurosis forms the aponeurotic layer of the scalp?

Answer 12

Occipital and frontal bellies of the occipitofrontalis muscle

Question 13

Which layer of the scalp facilitates movement?

Answer 13

Loose areolar tissue

Question 14

Recall the fossae of the skull

Answer 14

Anterior, middle and posterior cranial; cerebellar

Question 15

Recall the structures that pass through the foramen magnum

Answer 15

Medulla
Meninges (these surround medulla)
Vertebral and spinal arteries (brain needs blood supply)
Dural veins (brain needs draining)

Question 16

Which cranial fossa is the most shallow?

Answer 16

Anterior

Question 17

Recall the borders of each cranial fossa

Answer 17

Anterior = frontal bone to body and lesser wings of sphenoid
Middle = to dorsum sellae of sphenoid
Posterior  = to internal occipital proturberance

Question 18

Recall the relative positioning of the wings of the sphenoid bone

Answer 18

Lesser wing = anterior

2 lateral greater wings of sphenoid

Question 19

What lies posteriorly to the hypophysial fossa?

Answer 19

Dorsum sellae

Question 20

Recall the foramina of the sphenoid bone, from anterior to posterior

Answer 20

Optic canals
Orbital fissures
Foramen rotundum
Foramen ovale
Foramen spinosum
Foramen lacerum

Question 21

Recall the positioning of the sphenoid sinuses

Answer 21

There are 2: one anterior to and one posterior to the sphenoid body

Question 22

Recall the layers of the meninges from superficial to deep

Answer 22

Dura mater, arachnoid mater, pia mater

Question 23

Where do emissory veins run?

Answer 23

Originate in superficial fascia, drain into diploic vein within bone of skull

Question 24

Where does the cerebral vein run in relation to the meninges?

Answer 24

Deep to all of them

Question 25

Where is the subarachnoid space?

Answer 25

Between arachnoid mater and pia mater

Question 26

Describe the structure and structural properties of the dura mater

Answer 26

Thich and inelastic | Periosteal and meningeal layer

Question 27

Describe the structure and structural properties of the arachnoid mater

Answer 27

Elastic | Spider-like projections

Question 28

Describe the structural properties of the pia mater

Answer 28

Thin and delicate

Question 29

Which meningeal space is very large in the spine?

Answer 29

Extradural space

Question 30

What is the falx cerebri?

Answer 30

Fold of meningeal layer of dura mater that runs into the longitudinal fissure

Question 31

What is located at the base of the falx cerebri?

Answer 31

Inferior saggital sinus

Question 32

Where is CSF produced and where is this located?

Answer 32

Choroid plexus = superior part of inferior horn of lateral ventricle

Question 33

Recall the flow of CF from its production to its drainage

Answer 33

``` Lateral ventricle (choroid plexus) interventricular foramen 3rd ventricle cerebral aqueduct 4th ventricle *various foramina* subarachnoid space arachnoid granulation villi = drainage --> superior saggital sinus ```

Question 34

Why is an epidural bleed more dangerous in the skull than the spine?

Answer 34

Very small epidural space in brain so bleed is dangerous whereas in spine epidural space is large - ammeanable to CSF removal

Question 35

What is the tenorium cerebelli and what is its function?

Answer 35

Extension of the dura mater that separates the cerebellum from the inferior part of the occipital lobes

Question 36

Recall the foramina through which each of the cranial nerves enter

Answer 36

``` CNI = cribiform plate of ethmoid CNII = optic canal CNIII = superior orbital fissure CNIV = superior orbital fissure CNV1 = superior orbital fissure CNV2 = foramen rotundum CNV3 = foramen ovale CNVI = superior orbital fissure CNVII = internal acoustic meatus CNVIII = internal acoustic meatus CNIX = jugular foramen CNX = jugular foramen CNXI = jugular foramen CNXI spinal roots = foramen magnum CNXII = hypoglossal canal ```

Question 37

Recall the vascular components that enter the skull via the optic canal

Answer 37

Ophthalmic artery | Central artery of retina

Question 38

Recall the vascular components that enter the skull via the superior orbital fissure

Answer 38

Superior ophthalmic vein

Question 39

Recall the path of the internal carotid artery entering the skull

Answer 39

Enters via the carotid canal, turns a right angle and runs just posterior to foramen lacerum

Question 40

Recall the vascular components that enter the skull via the foramen spinosum

Answer 40

Middle meningeal artery and vein

Question 41

Recall the vascular components that enter the skull via the internal acoustic meatus

Answer 41

Labyrinthine artery

Question 42

Through which foramen of the skull does the sigmoid sinus drain into the internal jugular vein?

Answer 42

Jugular foramen

Question 43

Recall the components of the Circle of Willis, from anterior to posterior

Answer 43

2 x Anterior cerebral (connected by 2 x anterior communicating) Joins: Bilateral internal carotids (medial) and middle cerebrals (lateral) Posterior communicating arteries join them to the posterior cerebral Superior cerebellar Basilar Anterior inferior cerebellar Posterior inferior cerebellar Vertebral Anterior spinal

Question 44

What is the main danger of a cavernous sinus thrombosis?

Answer 44

Disruption of cranial nerve travelling through

Question 45

From which sinus does the great cerebral vein form?

Answer 45

Straight

Question 46

Name the sinus branches that travel around the sides of the brain

Answer 46

Transverse sinuses

Question 47

Which sinus encircles the IJV?

Answer 47

Sigmoid sinus

Question 48

What do the transverse sinuses converge to form?

Answer 48

Cavernous sinuses

Question 49

Why do scalp lacerations threaten the brain

Answer 49

Emissory veins provide a route of transmission of infection since they drain into deeper veins

Question 50

Where is the pterion and why is it clinically significant?

Answer 50

Where temporal, frontal, occipital and parietal bones meet Thin part of skull MMA runs just below = very vulnerable to extradural bleed

Question 51

Recall the names of the cranial nerves

Answer 51

1. Olfactory 2. Optic 3. Oculomotor 4. Trochlear 5. Trigeminal 6. Abducens 7. facial 8. Vestibulocochlear 9. Glossopharyngeal 10. Vagus 11. Accessory 12. Hypoglossal

Question 52

Describe the course of the facial nerve as it exits the skull

Answer 52

Exits skull via internal acoustic meatus and then stylomastoid foramen Runs over parotid gland Branches into 5 nerves supplying the face

Question 53

Where is the primary motor cortex located?

Answer 53

Pre-central gyrus

Question 54

Where is the primary somatosensory cortex located?

Answer 54

Post-central gyrus

Question 55

Recall the function of Wernicke's area

Answer 55

Sensory - speech

Question 56

Recall the function of Broca's area

Answer 56

Motor - speech

Question 57

Where are the colliculi seen on the brainstem?

Answer 57

Posteriorly, either side of pineal gland, on top of tectum

Question 58

Posteriorly, what is seen in the centre of the pons?

Answer 58

4th ventricle

Question 59

Recall some key distinguishing structures seen ANTERIORLY on the brainstem

Answer 59

Optic chiasm Pituitary stalk Mamillary bodies Cerebral peduncles