The procerus is an important facial expression muscle that lies just beneath the surface of the nasal bone. Its attachments include its origin at the nasal bone and its insertion at the skin of the lower medial forehead. Its main action is to pull the eyebrows down to create a frown-inducing transverse wrinkle over the nose. It is also innervated by buccal branches of the facial nerve, and is supplied with blood by the facial artery.
Facial expression muscles play an important role in the communication of emotions, along with the production of facial expressions such as a smile or a frown. They can also be used to emphasize and add nuance to a spoken message. In this way, facial expression muscles are an integral part of the language of facial expression.
The procerus is one of the facial expression muscles that is responsible for the production of a frown. It is unique in its location, as it is the only facial expression muscle to attach directly to the nasal bone. This gives it the ability to produce highly specific horizontal wrinkles over the nose. This is achieved by the muscle pulling the eyebrows downward, creating a furrowed brow. This is the characteristic facial expression associated with a frown.
The procerus is innervated by buccal branches of the facial nerve. The facial nerve is the main motor nerve of the face, and its branches provide sensory and motor innervation to the muscles of facial expression. The branches of the facial nerve that supply the procerus are known as the buccal branches and are located on the surface of the maxillary bone near the mouth. The procerus is also supplied with blood from the facial artery, which is a branch of the external carotid artery.
As with all facial expression muscles, the procerus plays an important role in the communication of emotion and the production of facial expressions. Its unique location and action give it the ability to produce highly specific and nuanced facial expressions which are integral to the language of facial expression.
The figure above shows the nasal muscles of facial expression. The procerus is located at the bottom of the figure and can be identified by its origin at the nasal bone, its insertion at the skin of the lower medial forehead, and its action of pulling the eyebrows downward to produce transverse wrinkles over the nose. It is innervated by the buccal branches of the facial nerve and supplied with blood by the facial artery.
The other nasal muscles of facial expression can also be seen in the figure. These muscles include the medial and lateral nasal muscles, which are responsible for the widening of the nostrils. The nasalis muscle, which originates from the maxilla and inserts on the nasal tip, is responsible for the elevation of the nasal tip and the narrowing of the nostrils. The depressor septi muscle, which originates from the maxilla and inserts on the medial part of the septal cartilage, is responsible for the downward movement of the nasal tip and the widening of the nostrils. The levator labii superioris alaeque nasi muscle, which originates from the maxilla and inserts on the ala of the nose, is responsible for the elevation of the nasal ala and the narrowing of the nostrils. Finally, the transverse nasalis muscle is responsible for the widening of the nostrils.
These muscles are all innervated by the buccal branches of the facial nerve and supplied with blood by the facial artery. They all have important roles in the production of facial expressions and the communication of emotion.
In conclusion, the procerus is an important facial expression muscle that lies just beneath the surface of the nasal bone. It has unique attachments, innervation, and blood supply and its action involves pulling the eyebrows downward to produce transverse wrinkles over the nose. This action helps to create the facial expression associated with a frown. The other nasal muscles of facial expression can also be seen in the figure. These muscles have important roles in the production of facial expressions and the communication of emotion.
