Galea Aponeurotica: the Sheet of the Scalp and Forehead
Quick facts
- Definition
- A tough fibrous sheet that covers the vault of the skull beneath the scalp skin.
- Location
- It joins the frontal belly to the occipital belly of the occipitofrontalis muscle.
- Relation to the forehead
- It acts as the tendon of the frontalis muscle: contraction pulls on the galea and lifts the eyebrows.
- Continuity
- It continues laterally as the temporoparietal fascia, in the temple region.
The galea aponeurotica is a fibrous sheet, firm and glistening, that covers the top of the skull just below the skin and subcutaneous tissue of the scalp. It is an aponeurosis: a flat, wide tendon. It is part of a continuous set of layers, described in layers of the face.
Where does it sit and what does it connect?
In front, it continues into the frontalis muscle, which runs up the forehead. Behind, it continues into the occipital belly. That is why the whole is called the occipitofrontalis. Laterally, the galea extends as the temporoparietal fascia and relates to the SMAS toward the face.
Why does it matter in HOF?
Because the frontalis does not insert into bone, it depends on the galea to transmit movement. When the muscle contracts, the galea is pulled forward and the forehead skin glides, forming the horizontal lines. This helps explain why the forehead is an area where mobility and the weight of the eyebrows weigh on the planning of the upper third.
Frequently asked questions
What is the galea aponeurotica for?
It transmits the force of the occipitofrontalis muscle, lets the scalp glide over the skull and supports the superficial layers of the forehead.