Neurovascular coupling and blood brain barrier Flashcards
What can brain scans reveal?
How brain function changes in response to a task, challenge or disease
What does fMRI stand for?
Functional Magnetic Resonance Imaging
What does fMRI detect?
Does not measure brain activity directly
This imaging detects signals associated with changes in cerebral blood flow
What does fMRI rely on?
The coupling between neuronal activation and cerebral blood flow
How does fMRI indirectly measure neural activity?
When neural activity in a region increases, blood flow to that region also increases
How active is the brain?
Most metabolically active of all organs in the body
How much does the brain weigh?
Roughly 2% of total body weight
How much cardiac output does the brain receive?
15%
How much body energy does the brain consume at rest?
20%
What does the brain not have?
Glycogen stores
What does the brain require because of the lack of glycogen stores?
Constant supply of glucose and O2 for ATP metabolism
Why does the brain use so much energy?
Communication of neurons requires a lot of energy
What is the main site of energy consumption?
Synapses
What is energy in the synapses for?
Energy is used to reverse the movement of ions at synapses during neuronal communication
What do synapses rely heavily on?
Local ATP synthesis
What is within each synapse which suggests the synapse needs a lot of energy?
Mitochondria
What is the ATP used to do in the synapse?
Resetting the synapse to its normal state
What is required to maintain synaptic activity?
Constant supply of glucose and oxygen
How are glucose and oxygen delivered to the brain?
Via its blood supply in cerebral circulation
What are the 2 sources the brain receive its blood supply from?
Arising from the dorsal aorta
o Common carotid→ internal carotid arteries
o Subclavian artery→ vertebral arteries
What do the right and left vertebral arteries join to form?
Single basilar artery
What does the basilar artery and two internal carotid arteries form?
Circle of Willis
Where is the Circle of Willis located?
Base of brain
What part is the Circle of Willis?
Arterial ring formed from basilar artery and internal carotid arteries