Cerebral physiology, primer
Nine compact chapters covering the physiology you need to make sense of every monitor on this site. Each chapter ends with a 3-question retrieval check.
- 1Foundation 1
Cerebral autoregulation
How the brain holds blood flow approximately constant across a range of perfusion pressures, and what happens when it can't.
- 2Foundation 2
CO₂ and O₂ reactivity
Why a single hyperventilation breath drops cerebral blood flow and an FiO₂ change usually doesn't.
- 3Foundation 3
Cerebral metabolism and flow-metabolism coupling
Why cerebral blood flow and metabolic rate normally track each other, and what it means clinically when they don't.
- 4Foundation 4
The Monro-Kellie doctrine
The cranial vault is rigid. Anything that adds volume must be paid for somewhere, first by CSF, then by blood, then by ICP.
- 5Foundation 5
The pressure-volume curve
Marmarou's exponential, why "ICP 18" tomorrow can mean trouble even though "ICP 18" today doesn't.
- 6Foundation 6
The Astrup ischemic cascade
As cerebral blood flow falls, EEG morphology degrades through stereotyped thresholds, and synaptic activity fails before cell death.
- 7Foundation 7
Spreading depolarizations
Slow waves of cellular collapse propagating across cortex, the secondary injury you can't see on routine monitors.
- 8Foundation 8
Blood-brain barrier physiology
Tight junctions, transporters, and selective permeability, and why a disrupted BBB changes how drugs and fluids behave.
- 9Foundation 9
Pediatric cerebral physiology
How CBF, CMRO₂, autoregulation, and ICP differ across the age bands you'll meet in PICU.