Washington Master Esthetics Practice Exam

Which muscle is responsible for the external contours of the neck?

1. Trapezius

2. Platysma

3. Sternocleidomastoid

4. Scalene

The correct answer is: Platysma

The platysma muscle is primarily responsible for the external contours of the neck. It is a broad, thin muscle that runs from the chest and shoulder area up to the mandible (jawbone). This muscle helps to create the appearance of the neck by pulling the skin of the neck and lower face downwards, contributing to its characteristic contour. It also plays a role in facial expressions, such as frowning or grimacing, as it can tense and pull the skin in a downward direction. The other muscles listed, while they serve important functions within the neck area, are not primarily responsible for shaping its external contours. The trapezius muscle, for instance, covers a larger area of the upper back and neck and is more involved in movements of the shoulders and head. The sternocleidomastoid assists in head rotation and flexion but does not define the neck's external appearance significantly. The scalene muscles, located deeper in the neck, are involved in breathing and neck movement but do not contribute to the outer profile of the neck like the platysma does.