Hi, welcome to my continuing series on anatomy for artists. Join me as I investigate anatomical texts to study how the human body can be accurately rendered in drawing. My sources include wikipedia, youtube, and textbooks (e.g. Gray's Anatomy and the OpenStax textbook on Anatomy & Physiology). My approach is to build a rudimentary understanding as relevant to figure drawing.

The eyebrows can be raised and furrowed by the frontalis and the corrugator muscles.

1. The frontalis connects the brow -- over the skull towards the back. Seen from the front, there is a bit of a V shape.

1. The corrugator furrows the brow. This creates a hooded effect and protects the eyes from the sun.

2. The procerus draws the brow further down. A wrinkle on the center between the brows is seen when this happens.

3. The nasalis flares the nostril.

1. Last, there is the orbicularus oculi

The eye itself closes because it is wrapped around by a muscle that starts and stops in the same place: the inner eye near the nose. When the muscle engages it pulls everything together and closes the eye.

With the shape of the frontalis and the action of the corrugator, we can decide on the placement of the eyebrow arch, when wrinkles appear during furrowing or raising the brow and the corresponding wrinkles in the face.

Thank you for reading and following my investigations.