How the Skull Protects the Brain: Six Mechanisms

The cranium employs multiple layered defenses:

1. Bony armor: Thick cortical bone absorbs/distributes impact forces.
2. Smooth, rounded contour: Deflects tangential blows; no sharp internal ridges.
3. Cerebrospinal fluid (CSF): Water cushion (150 mL) dampens acceleration-deceleration forces.
4. Meninges: Dura, arachnoid, pia mater—tough membranes anchoring brain, containing CSF.
5. Blood-brain barrier: Specialized endothelium restricts neurotoxin entry; maintains ionic homeostasis.
6. Sutures: Fibrous joints between cranial bones allow micro-movement, dissipating energy.

Together, these reduce traumatic brain injury risk, though severe forces can overwhelm them.