Anatomy of the Face and Head Underlying Facial Expression
The anatomy of the face and head is significant for understanding the behaviors, functions, and appearances of the face and head.
Several anatomical diagrams are collected here, although anatomy is not the focal topic of this web site and discussion of it is limited to the basics. Of necessity to avoid copyright violation, most diagrams are reproduced from old textbooks and journals, but they remain relatively accurate and are useful for introductory and illustrative purposes. A serious anatomy student would require a more modern and detailed treatment of these topics than is provided by diagrams and discussion found here.
The bony parts of the head, or the skull, form the framework on which the face is built.
The Atlas of the Skull page below shows the skull as a whole and discusses the two classes of bones in the head: cranial and facial. The page of More Skull Views has additional diagrams of the skull and its features. The Landmarks page shows the reference points of the face and head used by scientists. The Cranial Bones page shows these bones in more detail. The Facial Bones page likewise shows these bones in more detail.
The anatomy of muscles is most directly related to facial expression, as the muscles underlie these appearance changes.
The diagrams below depict the muscles of the face and head from several perspectives. A view may not show all the facial muscles, so look at several diagrams of each area. The Facial Muscles 3/4 View shows muscles in the outermost layer. The Lateral Views page shows the facial muscles and some head muscles from the side. The Eye Muscles page shows the muscles that control the movements of the eye. The tongue is composed of muscles and the Tongue Muscles page shows these and muscles that connect it to other structures. The Internal Jaw Muscles page shows some muscles that control jaw and tongue position, and the shape and movement of the tongue. More details of muscles are apparent in the Upper Face Muscles Details and Lower Face Muscles Details pages. The muscles that control eye movement are shown on the Eye Muscles page. The places where facial muscles attach to the bony skull (origins of muscles) are shown on the Attachments page. These muscles vary in the degree they contribute to facial expressions, but almost all of the muscles depicted can produce visible changes in appearance. These diagrams are particularly useful for visualizing the physical relationships of facial muscles to each other. A diagram of the functional aspects of facial muscles with video illustration is available on the muscle action page.
Neurons are specialized cells that form the brain, spinal cord, and nerve fibers. They carry messages to the muscles and other effectors, from sensors to the central nervous system, and also process these messages in centers called ganglia, nuclei, and much of the brain itself.
The Brainstem Nuclei and Tracts page below show the nerve centers in the brainstem most relevant to the production of facial expressions. Additional diagrams are shown on the Diagrams of Cranial Nuclei &
Nerve Tracts page. The Facial Nerve in Periphery page shows the peripheral nerves from the brainstem to the muscles in the face. The complicated peripheral Trigeminal is shown on the Trigeminal Nerve in Periphery page. Regions of the face that are innervated by different branches of nerves are shown on the Motor Regions page. Areas of sensory innervations of the face are presented on the Sensory Areas page. The Brain in Cranium page shows how the brain sits in the cranial vault and its relation to external landmarks. The conscious control of muscles and the awareness of cutaneous sensations is mediated by neural centers of the cortex of the cerebrum, and these centers are shown in the Cortical Representation page.
The vascular or circulatory system includes the arteries and veins that supply blood to the facial muscles, both superficial and deep, and the lymphatic system that are illustrated in the panel below.