the meninges and vasculature

Question 1

remember the 3 structures that for the meninges

duramater - periosteal layer covering inner skull

arachnoid - web structured fluid filled

pia mater- delicate, covers surface of brain

Question 2

where does the dural venous sinus structure sit in the brain

Answer 2

sits within the dura mater

Question 3

what structure separates the 2 cerebral hemispheres and what tissue is it found in

Answer 3

• falx cerebri (that sits in the longitudinal fissure)

Question 4

what structure separates the cerebrum from the cerebellum

Answer 4

cerebellar tentorium

Question 5

find and label all the components of the dual venous sinus system

Question 6

what are the 11 ranging purposes of CSF

Answer 6

• buoyancy of brain, spinal cord, nerves
• volume adjustment in cranial cavity
• nutrient transport
• protein/peptide transport
• brain volume regulation through osmoregulation
• buffering effect against external forces
• signal transduction
• drug transport
• immune system control
• elimination of metabolites and unnecessary substances
• cooling of heat generated by neural activity

Question 7

the choroid plexus produces around 50% of CSF, how much CSF is secreted into the ventricles by ependymal cells

Answer 7

500mls per fay

Question 8

remember that the CSF/ ventricles is continuous with the subarachnoid space

Question 9

what do you call that hole seen in the 3rd ventricle

Answer 9

interthalamic adhesion

Question 10

what is hydrocephalus and what causes it

Answer 10

• build up of fluid in brain
• occurs when theres blockage within the ventricular system OR
• reduced rate of reabsorption of CSF

Question 11

what can hydrocephalus look like on MRI

Answer 11

Enlarged ventricles

Question 12

what are the 3 types of strokes

Answer 12

ischaemic (blocked vessel supplying brain with blood)

hemorrhagic (ruptured weakened blood vessel)

transient ischemic attack (ministoke, temporary clot)

Question 13

what is a watershed cerebral infarction/ border zone infarcts

Answer 13

• infarctions that occur at border between cerebral vascular territories
• unique ischemic lesions which are situated along the border zones between the territories of the major cerebral arteries.w

Question 14

why do watershed cerebral infarctions occur/ prone to infarct. What percentage of strokes does it account for

Answer 14

• accounts for 5 - 10% of cerebral infarctions
• occurs as at the border between cerebral vascular territories is where the tissue is furthest from arterial supply and thus most vulnerable to reductions in perfusion

Question 15

what is hypoperfusion

Answer 15

reduced blood flow

Question 16

watershed cerebral infarct is primarily due to hypoperfusion, however there is another factor that contirbutes. what is it>

Answer 16

micro emboli from inflamed atherosclerotic plaque (a small particle, often a blood clot, that becomes caught while traveling through the bloodstream and can cause blockage in a blood vessel. )

Question 17

what does a watershed infarct look like on CT/MRI

Answer 17

• longitudinal darkened strip in the brain (due to infarct at the vascular borders)

Question 18

where is the most common area to get a stroke

Answer 18

middle cerebral artery (as it is a continuation of the inferior cerebral artery)

Question 19

compare the difference in a subdural and extradural haematoma as seen on scan

Answer 19

extradural/epidural haematoma = lemon shaped on edge

subdural haematoma = banana shaped wedge on edge of brain

Question 20

what type of blood is found in an extradural haematoma

Answer 20

• arterial blood (middle meningeal artery affected)

Question 21

what type of blood is found in subdural haematoma

Answer 21

• venous blood ( often ruptured cortical bridging vein)

Question 22

compare the speed of expansion of a sub/epi dural haematoma

Answer 22

extradural = rapidly expanding

subdural = slowly expanding

Question 23

subdural haematoma many cross suture line but epidural will not.

Question 24

what is the usually cause of a sub or epidural haematoma

Answer 24

subdural = convolution of gyri and sulci, torn cerebral vein

epidural = skull fracture (especially at pterion) (causing meningeal artery to break)

Question 25

refer back to all the images screenshotteds and fully recognised the cerebral artery, circle of willis, branches of aorta, dual vein structures, etc