Regulation of blood flow; blood brain barrier

Question 1

What are the 2 main sources of blood to the brain?

Answer 1

Internal carotid arteries

Vertebral arteries

Question 2

What is the Circle of Willis?

Answer 2

Where the anterior and posterior supply anastamose

Question 3

Recall the vessels that make up the Circle of Willis, from anterior to posterior

Answer 3

Ant. communicating
Ant. cerebral
Internal and mid. cerebral
post. communicating
posterior cerebral
basilar
vertebral

Question 4

Which arteries in the Circle of Willis are unpaired?

Answer 4

Anterior communicating and basilar

Question 5

Recall 3 symptoms of disruption to the anterior cerebral artery

Answer 5

1. Paralysis of contralateral leg with relative sparing of upper limb
2. Loss of appropriate social behaviour
3. Abulia

Question 6

Recall 4 symptoms of disruption to the middle cerebral artery

Answer 6

“Classic” Stroke:

1. Contralateral hemiplegia
2. Contralateral hemisensory defects
3. Hemianopia
4. Aphasia (for an LHS lesion)

Question 7

What is the main symptom of a posterior cerebral artery lesion?

Answer 7

Visual problems: bisual agnosia and homonymous hemianopia

Question 8

What is the pterion and what is its clinical significance?

Answer 8

Weak point in skull where 4 bones meet - close to MMA so rupture here is likely –> extradural haemorrhage

Question 9

Which type of brain haemorrhage is most dangerous and why?

Answer 9

Extradural - strips dura area and pushes brain down, quickly compromising the respiratory centre