The occipitofrontalis muscle, also known as the epicranius muscle, is a long, thin muscle located in the scalp and forehead region of the human body. It is responsible for the movement of the scalp and forehead, and plays a role in facial expressions and eye closure.
Structure
The occipitofrontalis muscle is made up of two parts: the occipitalis and the frontalis.
The occipitalis is the larger of the two parts and is located at the back of the head. It originates from the occipital bone and inserts into the galea aponeurotica, a tough, fibrous sheet of connective tissue located in the scalp. The frontalis muscle is located in the forehead region and originates from the galea aponeurotica. It inserts into the skin of the forehead and is responsible for the wrinkles that form when we raise our eyebrows.
Both the occipitalis and frontalis muscles are innervated by the facial nerve (CN VII). The occipitalis is responsible for pulling the scalp backward and upward, while the frontalis muscle raises the eyebrows and wrinkles the forehead. Together, these two muscles work to create the various facial expressions that are characteristic of human communication.
Location
The occipitofrontalis muscle is located in the scalp and forehead region of the head. It extends from the occipital bone at the back of the head to the skin of the forehead. The muscle is relatively thin and is located just beneath the skin, making it visible when it contracts.
Function
The main function of the occipitofrontalis muscle is to move the scalp and forehead. The occipitalis muscle pulls the scalp backward and upward, while the frontalis muscle raises the eyebrows and wrinkles the forehead. These movements allow us to express a wide range of emotions and communicate with others through facial expressions.
In addition to its role in facial expressions, the occipitofrontalis muscle also plays a role in eye closure. When we close our eyes, the occipitalis muscle contracts and pulls the scalp backward, helping to seal the eyelids shut.
Clinical significance
There are several clinical conditions that can affect the occipitofrontalis muscle. One common condition is forehead wrinkles, which can be caused by repeated muscle contractions and can be treated with Botox injections or other cosmetic procedures. Another condition is blepharospasm, a neurological disorder characterized by involuntary eye closure. Blepharospasm can be treated with medication or surgery to relax the muscles around the eye.
