Depressor septi nasi muscle

Depressor septi nasi muscle, also known as the transverse nasalis muscle, is a thin, narrow muscle located in the nasal region of the face. It is one of the muscles of facial expression, which are responsible for facial movements and expressions.^[2]

Structure

The depressor septi nasi muscle is a long, slender muscle that lies horizontally across the nasal septum, which is the central partition between the nostrils. It originates from the maxilla, a facial bone located just below the nose, and inserts into the cartilage of the nasal septum. The muscle is innervated by the facial nerve (cranial nerve VII).^[4]

Location

The depressor septi nasi muscle is located in the nasal region of the face, specifically within the nostrils.^[7] It lies horizontally across the nasal septum, which divides the nostrils.

Function

The main function of the depressor septi nasi muscle is to depress, or lower, the nasal septum. When the muscle contracts, it pulls the nasal septum downward, narrowing the nostrils.^[5] This action can help regulate airflow through the nostrils and can also help to filter out debris from the air we breathe.^[8] The depressor septi nasi muscle also plays a role in facial expression. It can contribute to the wrinkling of the skin around the nose, which is often seen when someone is frowning or expressing sadness or concern.

Clinical significance

The depressor septi nasi muscle can be affected by various medical conditions and injuries. For example, it can be damaged during a traumatic injury to the face, such as a car accident or sports injury.^[3] This can result in difficulty controlling the movement of the nasal septum, which can affect breathing and cause other respiratory issues. The muscle can also be affected by medical conditions such as Bell's palsy, a neurological disorder that causes temporary paralysis of the facial muscles.^[1] In such cases, the muscle may not be able to contract properly, which can affect facial expression and the ability to regulate airflow through the nostrils. In some cases, the depressor septi nasi muscle may be surgically altered or removed to treat certain medical conditions. For example, it may be removed as part of a surgical procedure to correct a deviated nasal septum, a condition in which the nasal septum is crooked or off-center.