Muscles of the head and neck

The muscles of the head and neck help us perform many important actions such as movement, mastication (chewing), speech, and facial expression. While most muscles only connect bones to bones, the facial muscles are unusual because they connect bones to skin. The muscles themselves are hard to see under the layers of other tissue, but as they contract they affect the surface layers, to give us our remarkably expressive faces. As artists we are interested in the muscles because of their role in communicating a person’s action, personality and mood.

We can divide the muscles into groups according to their function; they usually perform more than one action and often achieve their effects in combination. Here I offer a basic overview: as artists we are only interested in muscles that affect the surface, and I won’t try and outline every single muscle. For a comprehensive account of the attachments, insertions and functions of the muscles you should consult a good anatomy book like Valerie L. Winslow’s Classic Human Anatomy or Gary Faigin’s The Artist’s Complete Guide to Facial Expression. Maybe I will write about facial expressions another time as a general topic.

My paintings below illustrate most of the main muscles of the head and neck.

Muscles of mastication

The muscles of mastication move the mandible or jawbone. The strongest muscle in the jaw is the large masseter, which lies on the side of the jaw. It mainly closes the jaw and help us chew. The temporalis muscle attaches to the temporal fossa on the side of the skull and inserts on the mandible. You can sometimes see it bulge on the temple when the person is chewing. It mainly helps close the jaw.

Muscles of facial expression

The muscles of facial expression attach to the surface of the skull and insert into the face by fibres woven into the skin. When the fibres contract, the skin moves. The largest group is associated with the mouth. There are smaller groups of muscles that control the movements of the eyebrows and eyelids, the scalp, the nose, and the ear.

Eye

The corrugator sits on the inside corner of the orbit. It creates vertical wrinkles on the forehead and is known as the ‘frowning muscle’. You can’t see it in my illustrations as it sits underneath the orbicularis oculi.

The orbicularis oculi (not to be confused with the orbicularis oris) is a disc-shaped muscle that surrounds each eye socket. It closes the eyelids, acts on the eyebrows and cheeks, and makes ‘crow’s feet’ wrinkles around the eyes.

Nose

The fan-shaped procerus horizontally wrinkles the skin at the root of the nose. The nasalis or nose muscle extends down either side of the nose and flares the nostrils. Running down either side of the nose is the levator labii superioris alaeque nasi, sensibly known simply as LLSAN, which elevates the upper lip and the wing of the nose.

Slightly further out from the nose is the levator labii superioris, which elevates the upper lip. When it contracts it can produce a snarl, pulling up the side of the nose along with the lip.

Cheeks

The zygomaticus major and minor are the larger and smaller muscles of the cheekbone. The major draws the corner of the mouth outward and upward (smile); the minor draws the upper lip backward, upward, and outward (to make sad expressions).

Mouth

The orbicularis oris is a circular muscle performs various movements such as closing, compressing, puckering, and protruding the mouth. Other muscles move the lips or the corners of the mouth, helping us produce for example the range of movements necessary for speech. The horizontal buccinator (pron. ‘BUK-sinator’) muscle forms the muscular wall of the cheek and is related to chewing, suckling, whistling and smiling. When it contracts it can cause dimples on the corners of the mouth. It also helps produce expressions of contempt and smirking. The risorius draws the corner of the mouth outward and causes a dimple.

Chin

The depressor anguli oris or triangularis acts with the risorius to draw down the upper lip and close the mouth; it also draws the corner of the mouth downward. The depressor labii inferioris draws down the lower lip. In-between is a V-shaped muscle in the chin called the mentalis which raises and pushes up the lower lip, causing wrinkling of the chin, as in doubt, displeasure or determination. It is sometimes referred to as the ‘pouting muscle’.

Scalp

The epicranius, or scalp (also known as occipitofrontalis), contains two parts or ‘bellies’[1], the frontalis and the occipitalis. The frontalis extends from the hairline to the brow ridge; it draws the scalp forward and the eyebrows upward, and wrinkles the forehead. The occipitalis draws the scalp backward. These muscles are separated by the epicranial aponeurosis, a layer of dense fibrous tissue which covers the upper part of the cranium.

The neck

The neck muscles move the head in every direction, working in pairs on either side of the body. At the front, the muscles reach from the jawbone to the sternum and clavicle bones, helping us to move our jaw. The outer muscles at the side and back help move the head and neck.

The sternomastoid (or sternocleidomastoid) muscle extends from the breast (precisely, the clavicle and sternum bones) to the mastoid process of the skull and acts to flex and rotate the head. It has two ‘heads’, the medial (or sternal, i.e. attaching to the manubrium of the sternum) and lateral (or clavicular, i.e. attaching to the clavicle). The sternal head turns a person’s head to the opposite side and face upward; both heads together lift the face and tip the head backward.

In the front of the neck there is a group of ‘strap muscles’. The omohyoid muscle acts upon the hyoid and larynx. It attaches to the scapula by a part called the ‘inferior belly’, and swoops up to connect with the hyoid bone by its upper part or ‘superior belly’. Next to it are the sternohyoid and thyrohyoid which perform similar roles.

The platysma is a broad sheet that extends from the top of the chest muscle, over the base of the neck to the mandible and the corner of the mouth, overlapping the sternomastoid. (I omit it from the illustrations above as it would obscure the other muscles, so see below.) It depresses the lower jaw and draws down the corners of the lips, i.e. in expressions of fear or grimacing.

The laryngeal prominence – commonly known as the Adam’s apple – is a lump or protrusion formed by the thyroid cartilage surrounding the larynx. It is usually more prominent in adult men than in women or children. Below it is a second bump created by the thyroid gland, which is more developed in women than in men.

At the back of the neck is an area known as the posterior triangle of the neck. It contains several muscles. Its apex is where the sternomastoid and trapezius muscles meet at the occipital bone. 

What to do 

The first task is the ‘book-learning’. Get to know the information in this article, and for more detail supplement it with the books I mentioned, or others that cover the same thing. You can find lots of resources online too. The website Artnatomy has an amazing tool where you can select particular muscles to learn their locations and actions.

Fortunately, artists no longer need to personally dissect corpses, like Leonardo da Vinci, to get an adequate familiarity with the muscular system. I am not an anatomist, so my paintings of the muscles of the head above are based upon some simple research. They say nothing that is not said in countless other such diagrams. So why did I paint them? To help me learn the muscles of the head. For the same reason, you should paint them too. That’s your second task. Maybe your pictures will be more thrilling.

If you are wondering why you should bother, let me give one example of why knowing the muscles can be useful. We can smile using the risorius muscle that retracts the mouth, but this sort of smile looks insincere because a real smile involves the skin around the eyes. It raises the lips with the zygomaticus major and minor and causes ‘crow’s feet’ around the eyes using the orbicularis oculi. Knowing this sort of thing can help to make the difference between success and failure in capturing a particular expression. 

As you study the skull and the muscles of the face and neck, remember that they simply modify the solid structure of the basic form head. An illustration for teaching purposes is one thing, but a good drawing of the head should be a drawing of solid form, not a chart of the muscles beneath the surface.


[1] Some sources consider the occipitofrontalis to be a structure consisting of two distinct muscles, the frontalis and the occipitalis, rather than a single muscle with two parts.