Epicranial aponeurosis

Looks like

A tough, flat sheet of tendon covering the top of the skull like a helmet, linking the forehead muscle in front to the muscle at the back of the head.

What it does

Lets the forehead and back-of-head muscles pull against each other to move the scalp and raise the eyebrows.

Keeping it well

Scalp cuts that go through it gape wide and bleed a lot. Swelling that spreads over the head after a blow needs a doctor, especially in babies.

Related conditions

• Bell's palsy
• Tension-type headache