Structure and Function - Week 1 Blood Supply to the Brain Flashcards
What are the properties of the brain (2)
High metabolic demand:
- Consumes 20% of total energy supply
Body mass
- Brain – 2% of the body mass
Why is blood supply important to the brain? (3)
Neurons don’t store glucose
Loss of blood flow
- 10 sec = Loss of consciousness
- 20 sec = cessation of electrical activity
- 4-8 min = neuronal death
Describe cerebral blood flow and metabolism (4)
50ml/100gm/min on avg
Grey matter higher, white matter lower
CBF determined by balance between arterial blood pressure and intracranial pressure
Hypothermia is neuroprotective – better neurological recovery
Describe the basic circuit (5)
Aorta —> Arteries —> Arterioles —> Capillaries —> Venules —> Veins —> Vena cava —> Right atrium —> Right ventricle —> Pulmonary artery —> Lung capillary bed —> Pulmonary vein —> Left atrium —> Left ventricle —> Aorta
Which arteries arise from the aortic arch? (2)
Left and right subclavian artery
Which artery supplies blood to the brain? (1)
Internal carotid artery
How do the arteries enter the brain? (1)
Through carotid canal
What does the external carotid artery supply? (1)
Face muscles
What is the carotid sinus? (4)
Area of bifuraction of external and internal carotid artery
Slight bulge
Has special cells in wall of artery
Senses blood pressure and any changes in blood pressure will trigger feedback loops to return blood pressure back to normal
Which artery supplies to the posterior brain? (1)
Basilar artery
What are the basilar artery branches? (2)
Anterior inferior cerebellar arteries (AICA)
Superior cerebellar arteries (SCA)
Pontine arteries
What are the branches of vertebral artery? (3)
Anterior spinal arteries (ASA)
Posterior spinal arteries (PSA)
Posterior inferior cerebellar arteries (PICA)
What joins the internal carotid and basilar arteries? (1)
Circle of Willis
Anterior circulation is fed by what? (1)
Carotid artery
Posterior circulation is fed by what? (1)
Basilar artery