Cranium and brain

Question 1

Identify the different tissue components of the scalp

Answer 1

Skin - highly vascular, sweat glands, sebaceous glands, hair follicles
Connective tissue - supplied by cutaneous nerves, highly vascularised
Aponeurosis - membranous sheet
Loose connective tissue - not continuous with the pericranium, allows movement of the scalp
Pericranium - dense connective tissue continuous with the endocranium

Question 2

Which parts of the brain sit in:

• Anterior cranial fossa
• Middle cranial fossa
• Posterior cranial fossa

Answer 2

Anterior - frontal
Middle - Temporal
Posterior - Cerebellum and brainstem

Question 3

Layers of the meninges

Answer 3

Dura mater (periosteal outside and meningeal inside)
Arachnoid mater
Pia mater

Question 4

What divides the 2 cerebral hemispheres

Answer 4

Falx cerebri

Question 5

Falx cerebra is attached

Answer 5

Anteriorly to the ethmoid and frontal bones

Posteriorly it blends with the tentorium cerebelli

Question 6

Tentorium cerebelli divides

Answer 6

cerebrum from cerebellum

Question 7

Tentorium cerebelli is attached

Answer 7

Posteriorly to the occipital bone, laterally to the superior border of the temporal bone

Question 8

The anterior and medial borders of the tentorium cerebelli are free and form an oval opening in the midline called the

Answer 8

Tentorial notch

Question 9

What passed through the tectorial notch

Answer 9

midbrain

Question 10

The subarachnoid space enlarges in certain areas called

Answer 10

subarachnoid cisterns

Question 11

CSF is produced by

Answer 11

choroid plexus (where the vessels of the pia mater come into contact with the ependymal lining of the central canal)

Question 12

Flow of CSF

Answer 12

Flows through ventricles - lateral –> 3rd –> aqueduct –> 4th –> central canal (v little actually flows through the central canal, most enters the subarachnoid space)

Question 13

CSF returns to the venous system via the

Answer 13

arachnoid villi (project as arachnoid granulations into the superior sagittal sinus)

Question 14

What is hydrocephalus and mechanisms

Answer 14

Dilatation of the cerebral ventricular system

Overproduction of CSF. Obstruction of flow of CSF. Failure to reabsorb CSF.

Question 15

explain herniation

Answer 15

When a space occupying lesion (blood, tumour, oedema, cyst) causes a rise in intracranial pressure and causes the brain to shift cross structures within the skull

Question 16

Types of herniation

Answer 16

Subfalcine (most common)
Uncal
Tonsillar

Question 17

Subfalcine herniation

Answer 17

When innermost parts of the frontal lobe shifts under part of the falx cerebri

May interfere with blood vessels to the frontal lobe

Question 18

Brain receives blood supply from:

Answer 18

Vertebral arteries and internal carotid arteries

Question 19

The 2 vertebral arteries enter the cranial cavity through the….
they fuse just inferior to the …. to form the…

Answer 19

foramen magnum

fuse inferior to the pons to form the basilar artery

Question 20

The internal carotid arteries enter the cranial cavity through the…

Answer 20

Carotid canals

Question 21

Describe the venous drainage of the brain

Answer 21

Blood drains into the small venous channels, then into the larger cerebral, cerebellar and brainstem veins, then into the dural venous sinuses

Question 22

what are the dural venous sinuses

Answer 22

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

Question 23

the dural venous sinuses lead to the

Answer 23

internal jugular veins

Question 24

Superior sagittal sinus receives blood from

Answer 24

cerebral veins from the superior surface of the cerebral hemispheres, diploid and emissary veins and veins from the fall cerebri

Question 25

Blood from the superior sagittal sinus drains

Answer 25

posteriorly | at the internal occipital protuberance it turns right to form the right transverse sinus

Question 26

as the right transervse sinus passes the ... it turns into the ...

Answer 26

petrous temporal bone | sigmoid sinus

Question 27

which 2 sinuses/veins join to form the straight sinus

Answer 27

inferior sagittal sinus and great cerebral vein

Question 28

the straight sinus drains....and turns left at the .... to form the

Answer 28

posteriorly | internal occipital protuberance to form the left transverse sinus

Question 29

The straight sinus receives blood from the

Answer 29

inferior sagittal sinus cerebral veins superior cerebellar veins veins from the fall cerebri

Question 30

which sinuses empty into the confluence of sinuses

Answer 30

superior sagittal straight sinus occipital sinus in the fall cerebra

Question 31

what is the confluence of sinuses and where is it

Answer 31

a dilated space | at the internal occipital protuberance

Question 32

the confluence of sinuses drains into

Answer 32

the left and right transverse sinuses

Question 33

as the transervse sinuses leave the ... bone they becomes the

Answer 33

occipital bone | sigmoid

Question 34

the sigmoid sinuses end at the beginning of the

Answer 34

internal jugular veins

Question 35

where are the paired cavernous sinuses

Answer 35

on the lateral aspect of the body of the sphenoid bone | the right and left sinuses lie either side of the pituitary fossa

Question 36

cavernous sinuses receive blood from...

Answer 36

cerebral veins emissary veins ophthalmic veins

Question 37

the cavernous sinuses communicate with the transverse sinuses and internal jugulars via

Answer 37

petrosal sinuses

Question 38

Where do the diploid veins run? | Drain into

Answer 38

between the internal and external tables of compact bone in the roof of the cranial cavity drain into dural venous sinuses

Question 39

Emissary veins pass from to

Answer 39

from outside the cranial cavity into the dural venous sinuses

Question 40

Why are the emissary veins important clinically?

Answer 40

they are a conduit for which infections can enter the cranial cavity because they have no valves

Question 41

which vein acts as a conduit for infection from the face to the brain? What does it connect with?

Answer 41

Facial vein | with the cavernous sinus

Question 42

What is the pterion? and its clinical significance?

Answer 42

The point where the frontal, temporal, parietal and sphenoid bones all meet on the lateral aspect of the skull thinnest and weakest part of the skull anterior division of the middle meningeal artery lies deep to the pterion - injury can cause extradural haemorrhage severe damage can affect deeper branches of the MCA - subarachnoid haemorrhage

Question 43

What goes through the cribriform plate?

Answer 43

Olfactory

Question 44

What goes through the optic canal

Answer 44

Optic nerve | ophthalmic artery

Question 45

What goes through the superior orbital fissure

Answer 45

``` Oculomotor Trochlear Trigeminal a - ophthalmic division Abducens superior ophthalmic vein ```

Question 46

What goes through the foramen rotundum

Answer 46

Trigeminal b - maxillary division

Question 47

What goes through the foramen ovale

Answer 47

Trigeminal c - mandibular division

Question 48

What goes through the foramen spinosum

Answer 48

middle meningeal artery and vein

Question 49

What goes through the carotid canal

Answer 49

internal carotid artery

Question 50

What goes through the internal acoustic meatus

Answer 50

Facial Vestibulocochlear labyrinthine artery

Question 51

What goes through the jugular foramen

Answer 51

Glossopharyngeal Vagus Accessory

Question 52

What goes through the hypoglossal canal

Answer 52

Hypoglossal

Question 53

What goes through the foramen magnum

Answer 53

Vertebral arteries medulla of brain spinal roots of accessory nerve