Anatomy of the brain Flashcards
How is blood delivered to the brain?
through 4 main arteries:
- 2 internal carotid arteries (anterior supply)
- 2 vertebral arteries (posterior supply, cerebellum + brain stem)
form the Circle of Willis
What 2 arteries form the Basilar artery?
2 vertebral arteries
What are watershed areas in the brain?
where arteries come in close contact with each other
often affected 1st by blockage/haemorrhage as they are the ends of the arteries
What does the CNS consist of?
brain
spinal cord
Name the 4 brain lobes
frontal
parietal
temporal
occipital
Describe grey and white matter
grey = neuronal cell bodies - business end
white = myelinated axon - wiring
What is decussation?
nerves crossing in brain stem
this is why stroke symptoms are on opposite side to affected brain area
How does a stroke affecting the middle cerebral artery present?
Contralateral:
- hemiparesis, arm worse than leg
- facial weakness
- sensory loss
- dysphasia
- dysarthria
- hemianopia
How does a stroke affecting the anterior cerebral artery present?
Contralateral:
- hemiparesis, leg worse than arm
- incontinence
- apathy
- disinhibition (lack of restraint)
- mutism
How does a stroke affecting the posterior cerebral artery present?
Contralateral:
- hemianopia
- amnesia
- sensory loss (thalamus)
- thalamic pain
How does a stroke affecting the vertebrobasilar artery present?
Combinations of:
- hemiparesis
- hemisensory loss
- vertigo, vomiting
- diplopia
- facial weakness/numbness
- dysphagia
- cerebellar ataxia
- respiratory failure
- coma + death
How does a Lacunar stroke present?
pure motor
pure sensory
sensorimotor
ataxic hemiparesis
Define Lacunar stroke
occlusion of one of the penetrating arteries that provides blood to the brain’s deep structures
