Anatomy 5

Question 1

increased intracranial pressure can cause what to happen?

Answer 1

herniation

Question 2

what are the 5 layers of the scalp?

Answer 2

SCALP
skin
connective tissue
aponeurosis
loose connective tissue
pericranium

Question 3

where are the named arteries of the scalp found?

Answer 3

in connective tissue layer of the scalp

Question 4

scalp anastomoses of arteries come from where?

Answer 4

external carotid artery

Question 5

function of sutures (fibrous joints between bones of skull)

Answer 5

minimises propagation (spreading) of skull fractures

Question 6

what is the pterion?

Answer 6

H shaped suture between frontal, parietal, temporal and sphenoid bone
one of the thinnest part of the skull

Question 7

what passes under the pterion?

Answer 7

middle meningeal artery

courses over the deep aspect of the pterion, therefore susceptible to damage

Question 8

what passes through jugular foramen?

Answer 8

internal jugular vein

CNs 9, 10, 11

Question 9

describe features of each layer of meninges

Answer 9

dura = tough and fibrous, CN V sensory supply, encloses dural venous sinuses between periosteal and meningeal layer
arachnoid = has arachnoid granulations to reabsorb CSF, subarachnoid space encloses CSF
pia mater = adherent to brain/blood vessels/nerves

Question 10

only what layer of the dura covers the spinal cord?

Answer 10

only the meningeal part

- periosteal part only in skull

Question 11

features of dura mater in the skull?

Answer 11

tentorium cerebelli
- tents over cerebellum and attaches to ridges of petrous temporal bones, has a gap for brainstem
diaphragm sellae
- tough sheet of dura forming a roof over pituitary fossa
falx cerebri
- midline structure separating right and left hemispheres

Question 12

venous drainage of the brain?

Answer 12

cerebral veins > dural venous sinuses

Question 13

names of the dural venous sinuses?

Answer 13

superior sagittal sinus
inferior sagittal sinus
left sigmoid sinus
confluence of sinuses

Question 14

function of dural venous sinuses?

Answer 14

drain blood and CSF

Question 15

danger triangle?

Answer 15

area over the nose where superficial veins then track back to deep veins and then to the brain
therefore superficial infection can spread to the brain

Question 16

arterial supply to the brain?

Answer 16

common carotid > internal carotid

vertebral artery

Question 17

circle of willis if formed from what arteries?

Answer 17

vertebral > basillar > posterior cerebral arteries
middle cerebral arteries
anterior cerebral arteries

Question 18

middle cerebral artery is a direct continuation of what?

Answer 18

internal carotid

Question 19

where is the circle of willis located?

Answer 19

subarachnoid space
inferior to midbrain
close to pituitary stalk and optic chiasm

Question 20

where does the subarachnoid space end?

Answer 20

S2 level

Question 21

what is hydrocephalus?

Answer 21

excessive production, obstruction to flow or inadequate reabsorption leading to an increased CSF volume

Question 22

how can hydrocephalus be managed?

Answer 22

ventricular peritoneal shunt
- shunt catheter is tunnelled beneath the skin of the neck and chest then sited within the peritoneal cavity where the CSF is absorbed

Question 23

what causes an extradural haemorrhage?

Answer 23

ruptured middle meningeal artery

trauma to the pterion

Question 24

what causes a subdural haemorrhage?

Answer 24

torn cerebral veins
falls in the elderly
(separates dura from arachnoid)

Question 25

what causes a subarachnoid haemorrhage?

Answer 25

ruptured circle of willis (“berry”) aneurysm

congenital aneurysm

Question 26

supratentorial herniation?

Answer 26

herniation of structures above the tentorium cerebelli
types
- cingulate (into a fissure)
- central (into the middle)
- uncal/transtentorial (uncus of temporal lobe herniates downwards)
- transcalvarial (outwards to the skull through meninges)

Question 27

infratentorial herniation?

Answer 27

herniation of structures below the tentorium cerebelli
upward
or downward/tonsillar herniation (the cerebellar tonsils herniate into the foramen magnum)

Question 28

how can an uncal herniation cause a blown (dilated) pupil?

Answer 28

can compress the oculomotor nerve