Musculus epicranius is a muscle located on the scalp that is responsible for raising the eyebrows and wrinkles the forehead. The spelling of this word can be broken down phonetically as muh-skyuh-luhs eh-puh-krey-nee-uhs, with the IPA transcription as /ˈmʌskjʊləs ˌɛpɪˈkreɪniəs/. The word "musculus" is derived from the Latin term "musculi" which means muscle, and "epicranius" is a compound of the Greek words "epi" meaning upon, and "kranion" meaning skull. Together, the term defines the location of the muscle on the skull.
Musculus epicranius refers to a paired muscle complex located on the scalp that plays a vital role in certain facial expressions and movements of the forehead and scalp region. Composed of two main muscles, the frontalis and the occipitalis, musculus epicranius is responsible for raising the eyebrows and causing wrinkling or folding of the forehead.
The frontalis muscle is situated at the front of the head and extends from the frontal bone to the aponeurosis or tough tendon-like structure on the top of the head, known as the galea aponeurotica. Its main function is to elevate the eyebrows and create horizontal lines or forehead wrinkles when contracted. Conversely, the occipitalis muscle, located at the back of the head, connects the galea aponeurotica to the occipital bone. Its primary role is to retract the scalp and counteract the frontalis muscle when relaxed.
Together, these muscles contribute to various facial expressions, such as raising the eyebrows in surprise, disbelief, or concern. Additionally, the musculus epicranius assists in forehead movements like wrinkling or smoothing, depending on the contraction or relaxation of its constituent muscles.
Overall, the musculus epicranius is essential for facial expressions that convey a range of emotions and communicative cues, contributing to our nonverbal communication and expression of thoughts and feelings.
M. Occipitofrontalis, the scalp muscle, formed of two bellies, the frontalis and the occipitalis, and a central aponeurosis, the galea aponeurotica.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The term "musculus epicranius" is derived from Latin. It can be broken down into two component parts:
1. "Musculus": This word means "muscle" in Latin. It comes from the diminutive form of "mus" which means "mouse". The resemblance between a mouse's movements and the contractions of a muscle led to the use of "mus" to describe muscles.
2. "Epicranius": This term consists of two Latin words:
- "Epi" means "upon" or "above" in Latin.
- "Cranium" means "skull" in Latin.
The term "Epicranius" is used to describe a specific muscle group located on the scalp above the cranium (skull). It is a combination of the words "epi" and "cranium", referring to the placement of the muscle.