Blood Supply to the Brain
The Brain's Vascular Network
The brain is one of the most energy-demanding organs in our body, requiring a constant and rich supply of oxygen and nutrients. Let's dive into how this remarkable system works!
Major Arteries
- Internal Carotid Arteries
- Two main vessels that supply the front and middle portions of the brain
- Carry about 80% of the brain's blood supply
- Branch into smaller arteries that feed different brain regions
- Vertebral Arteries
- Run through the vertebrae in the neck
- Join to form the basilar artery
- Supply the brain stem and back of the brain
The brain receives about 15-20% of the body's total blood supply, despite making up only 2% of body weight!
The Circle of Willis
The Circle of Willis is nature's backup system for brain blood supply. It's a circular connection of arteries that ensures if one blood vessel gets blocked, others can compensate.
Key components include:
- Anterior cerebral arteries
- Middle cerebral arteries
- Posterior cerebral arteries
- Communicating arteries that connect them
Think of the Circle of Willis as a traffic roundabout system - if one road is blocked, traffic can still flow through alternative routes!
Blood-Brain Barrier
While discussing brain blood supply, we can't ignore the blood-brain barrier:
- Acts as a selective filter
- Protects brain tissue from harmful substances
