cerebral vasculature Flashcards
between which two layers are sinuses formed?
between 2 dura layers (outer periosteal and inner meningeal)
what procession of vessels does the blood drain through from the brain to the neck (on its way to the heart)
cerebral veins-> dural venous sinuses -> internal jugular vein
4 types of brain haemorrhage
extradural, subdural, subarachnoid, intracerebral
cause of extradural haemorrhages
trauma
does it take long for clinical effects to manifest in extradural haemorrhages and why?
immediate bc they are arterial: high pressure
does it take long for clinical effects to manifest in subdural haemorrhages and why?
no because they are venous: low pressure
cause of subarachnoid haemorrhages
aneurisms
what causes aneurisms?
they are a developmental abnormality
intracerebral haemorrhage cause
spontaneous hypertensive
What is the medical term for a stroke?
cerebrovascular accident (CVA)
definition of stroke
1) RAPIDLY DEVELOPING
2) focal (of central importance) disturbance of brain function
3) of presumed vascular nature and
4) over 24 h duration
cause/ nature of most strokes (85%)
thromboembolic - blockages
cause/ nature of 15% of strokes
haemorrhage
what is the difference between a TIA and CVA (stroke)?
a TIA resolves within 24 hours (clot is broken down naturally) whereas a CVA doesn’t
what is ischemia in the brain
THE LACK OF BLOOD FLOW to nervous tissue. this leads to permanent damage if the blood flow is not restored quickly
what is infarction
DEGENERATIVE CHANGES (dead ground) which occur in tissue following occlusion of an artery
What is thrombosis
formation of a blood clot (thrombus)
what is embolism
plugging of a small vessel by material carried from a larger vessel (eg thrombi from the heart or atherosclerotic debris from the internal carotid)
why is it important to raise awareness on strokes? how do they impact society
major public health issue, 3rd commonest cause of death, 100,000 deaths in uk per year, 50% of survuvors permanentely disabled, 70% obvious neurological defect
risk factors of stroke
Age (general wear and tear on vascular system)
Hypertension (spontaneous bleeds and ruptured vessels)
Cardiac disease (anything involving disturbed blood flow)
Smoking
Diabetes mellitus (because they are vascular risk factors)
most common type of occlusive stroke (which artery is occluded)
middle cerebral artery occlusion
what vessels provide the primary motor cortex with blood
middle cerebrla and anterior cerebral arteries
symptoms of anterior cerebral artery blockage
1) paralysis of contralateral leg> arm
2) disturbance of intellect, executive function and judgement (abulia)
3) loss of appropriate social behaviour
middle cerebral artery occlusion symptoms
1) contralateral hemiplegia: arm> leg
2) contralateral hemisensory (feeling altered sensation) deficits
3) hemianopia
4) aphasia
