Week 2 Flashcards
(179 cards)
What are the two connected sources of arterial blood for the brain?
Ant. and post. circulation
What vessel supplies the anterior circulation of the brain?
Int. Carotid a.
What does the Anterior circulation of the brain supply with blood?
Ant. 3/5 of cerebrum
Diencephalon
Int. capsule
What are the 3 main branches of the Int. Carotid a.?
Middle cerebral a.
Ant. cerebral a.
Perforating branches
What is an Endarterectomy?
Removal of plaque from an artery
What vessel supplies the posterior circulation of the brain?
Vertebrobasilar a.
What does the Posterior circulation of the brain supply with blood?
Brainstem
Cerebellum
Post. 2/5 of cerebrum
Diencephalon
What are the main branches of the Vertebrobasilar a.?
Cerebellar (PICA, AICA, SCA)
Pontine
Post. cerebral
Striate & thalamic branches
What vessels supply the Midbrain?
-Post. Cerebral-
post. communicating
sup. cerebellar
What vessels supply the Pons?
-Basilar-
ant. inf. cerebellar (AICA)
What vessels supply the Medulla?
-Ant. Spinal-
post. spinal
ant. + post. inf cerebellar (AICA, PICA)
What rate will the brain try to keep the blood flow at?
50 ml/min
What happens if the blood pressure in the brain drops below 50 mmHg?
The blood vessel will try to dilate, but due to lack of pressure keeping it open, it will collapse. This leads to Ischemia
What happens if the blood pressure in the brain raises above 150 mmHg?
The blood vessel will dilate to try and reduce blood pressure leading to high bp and high volume. This leads to Vasogenic Oedema
What is Steal syndrome
If patient has stenosis in subclavian a. before it branches to vertebral a. the limb, if used excessively, will not get enough blood from subclavian a. alone. Therefore blood that would go to the brain via the vertebral a. is instead taken to the limb, depriving the brain of blood
What are the symptoms of a Stroke?
Facial asymmetry
Speech disturbance (dysphasia)
Asymmetrical weakness in muscles
What is a Stoke?
Loss of neurological function due to impaired blood supply to brain
What is the difference between a Stroke and a Transient ischemic attack (TIA)?
In a Stroke the symptoms must last longer than 24 hrs or lead to death with no apparent cause other than that of vascular origin
What are the 3 types of Stokes?
Ischemic (80%)
Haemorrhagic (15%)
Subarachnoid haemorrhage (5%)
What are the 3 main causes of a Haemorrhagic stroke?
HT, Tumour, Bleeding disorder (or blood thinners ie. warfarin)
What are the primary brain damages of a haemorrhagic stroke?
Mechanical damage associated with the mass effect, within minutes to hours of bleeding onset
What are the secondary brain damages of a haemorrhagic stroke?
Surrounding oedema, oxidative stress, comorbidities ie. age
What is the main causes of Ischemic strokes?
Cardio-Embolisms (clots)
Small vessel disease (diabetes)
What happens in lacunar stroke?
Type of ischemic stroke where lacunar striate arteries are blocked leading to necrosis that forms small cavities in the brain