The depressor septi nasi muscle (or depressor alae nasi muscle) is a

muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

of the face. It connects the incisive fossa of the

maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

and the orbicularis oris muscle to the

nasal septum The nasal septum () separates the left and right airways of the Human nose, nasal cavity, dividing the two nostrils. It is Depression (kinesiology), depressed by the depressor septi nasi muscle. Structure The fleshy external end of the nasal s ...

of the nose. It draws the

ala of the nose The human nose is the first organ of the respiratory system. It is also the principal organ in the olfactory system. The shape of the nose is determined by the nasal bones and the nasal cartilages, including the nasal septum, which separates ...

downwards, reducing the size of the

nostril A nostril (or naris , : nares ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbinates ...

Structure

The depressor septi nasi muscle arises from the

incisive foramen In the human mouth, the incisive foramen (also known as: "''anterior palatine foramen''", or "''nasopalatine foramen''") is the opening of the incisive canals on the hard palate immediately behind the incisor teeth. It gives passage to blood ves ...

of the

. It may also partially originate from the orbicularis oris muscle. Its fibers ascend to be inserted into the

and back part of the alar part of

nasalis muscle The nasalis muscle is a sphincter-like muscle of the Human nose, nose. It has a transverse part and an alar part. It compresses the nasal cartilages, and can "flare" the Nostril, nostrils. It can be used to test the facial nerve (VII), which suppl ...

. It lies between the

mucous membrane A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It ...

and the muscular structure of the

lip The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...

Function

The depressor septi is a direct antagonist of the other muscles of the nose, drawing the

downward, constricting the nostrils. It works like the alar part of the

Clinical significance

During

rhinoplasty Rhinoplasty (, nose + , to shape), commonly called nose job, medically called nasal reconstruction, is a plastic surgery procedure for altering and reconstructing the human nose, nose. There are two types of plastic surgery used – plastic sur ...

, repositioning of the head of the depressor septi nasi muscle ensures normal nose position after

surgery Surgery is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (e.g., malabsorption created by bariatric surgery s ...

. Various approaches may be used, with similar results.

Additional images

File:Depressor septi nasi muscle animation small.gif, Position of depressor septi nasi muscle (shown in red).

References

{{Authority control Muscles of the head and neck Human head and neck Facial muscles