anatomy of the human skull

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Anatomy of the Human Skull

The human cranium and the facial bones are the foundation for the soft tissues of the face and

head. Thus, much of the visible appearance of the human face depends upon the shapes andqualities of these bones. The cranium is that part of the skull that holds and protects the brain in

a large cavity, called the cranial vault. Eight plate-like bones form the human cranium by fittingtogether at joints called sutures. The most important of these cranial bones for the appearance of

the face is the frontal bone, which underlies the top of the face above the eyeballs. The humanskull also includes 14 facial bones that form the lower front of the skull and provide the

framework for most of the face that is important to psychological research. These 22 skull bones form other, smaller cavities besides the cranial vault, including those for the eyes, the internal

ear, the nose, and the mouth. The important facial bones include the jaw bone or mandible, themaxilla or upper jaw, the zygomatic or cheek bone, and the nasal bone.

The shapes and features of the human skull determine much of the static appearances of the faceand provide the basis for the features of physiognomy. Forensic pathologists and biologists can

reconstruct the superficial appearance of a face merely from the human skull, as in the case of the Kennewick Man. The reconstruction of this skull revealed a facial appearance that indicates

he is a descendant of a more ancient migration from Asia than that which brought the ancestorsof the Indians (Amerinds), who settled widely in the Americas before the arrival of Europeans.

The skull bones are associated with many other features. Processes are areas where the bones

have extra tissue to hold muscles and ligaments; lines are grooves in the bone from other developmental processes; foramina are holes in the bones through which nerves and blood

vessels pass; sinuses are empty spaces in the bones that make the skull lighter. Some of thesefeatures affect the physiognomy of the face due to variations in thickness, size, location, and

shape.

The diagrams below show the major external features of the human cranium and the major skull bones. The names in black are facial bones, those in red are cranial bones, and those in blue

are features of the bones.



frontal view

side view



Feature Location Description

angle of jaw or

mandible back of jaw

the corner of the jaw where the mandible body turns

upwards into the ramus

aveolar process maxilla, root of teeth rugosities associated with tooth development

condyle of mandible

top of ramus of mandible

a ball-like end to the ramus of the mandible thatforms a hinge with the temporal bone

coronal suture

top of head between

frontal and parietalcranial bones

one of the major joints or sutures between the platesof the frontal and parietal cranial bones

external acoustic

meatus

between ramus of

mandible andmastoid process

a hole in the temporal cranial bone allowing the

passage of sound to enter the inner ear

ethmoid bone eye cavity a cranial bone forming part of the eye cavity

forehead boss or frontal tuberosity forehead

a feature of the frontal bone that forms the "bumps" inthe forehead above the eyebrows

frontal bone top of face(forehead) and front

top of head

one of the major cranial bones that forms the foreheadand front top of the head; roughly covers the frontal

lobes of the brain

glabella center of foreheadan area in the center of the forehead, between theeyebrows, that assumes various shapes on different

individuals

lacrimal boneinner corner of eye

socketa small bone forming a cavity for the tear gland

lambdoid suture back of head suture or joint between the occipital and parietalcranial bones

mandible or jaw

bonelower part of jaw

the lower jaw bone is the only skull bone that moves,i.e., during mastication, speech, and expression;

carries the lower teeth

maxilla upper part of jaw

the two maxillae form the center of the face withmany attaching muscles; carry the upper teeth; form

part of the eye orbit; act like keystones into which theother facial bones fit

mastoid process lower part of temporal bone,

behind ramus of jaw

built up area of the lower temporal bone where

important neck muscles attach

mental protuberance

chin bossa feature of the mandible at the lower front part of thechin which underlies part of the chin boss

mentaltuberosities

chin bossa dual bulbous formation of the mandible thatunderlies part of the chin boss

nasal bone nose forms the upper part of the nose and nasal bridge; the



lower part of the bridge is formed of cartilage

nasal concha nasal cavity formations creating part of the nasal cavity

nasal spine center of nosefeature of maxilla facial bone at center of nose towhich septum is attached

occipital bone the lower rear of thehead

a major cranial bone at the lower back of the head;covers occipital lobe of the brain

parietal bone top and side of head

a major cranial bone that froms part of the top, back,

and side of the head and roughly covers the parietallobe of the brain

ramus of

mandible

back part of the

mandiblethe more vertical part of the mandible

sphenoid bone temple and eye orbit

areaa cranial bone that forms part of the eye cavity

squamosal suture side of head between parietal and temporal

bones

one of the major joints or sutures between the parietaland temporal cranial bones

supraorbialforamen

upper orbit of eye

a hole in the frontal bone where nerves and blood

vessels pass through; forms a notch in the orbit of theeye

supraorbital

process eyebrows

a formation of the frontal bone above the orbit of the

eye, under and above the eyebrows that affects theappearance of the eyebrows

temporal bone side of the head,

above the ear

a cranial bone on the side of the head that roughlycovers the temporal lobe of the brain; it extends down

behind the ear towards the jaw

temporal lines front part of templeand lower part of

frontal bones

lines in the frontal bone around the temple

volmer nasal cavitya facial bone on the centerline of the nose that forms part of the nasal cavity

zygomatic bone cheek the principal cheek bone; origin of zygomatic andother facial muscles

zygomatic

process

bones bordering

zygomatic bone

the temporal and maxilla bones have areas next to the

zygomatic bone

Images copyright © Corel Corp - do not copy.

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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, althoughanatomy 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.

Skeletal Anatomy

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 thehead: 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 byscientists. The Cranial Bones page shows these bones in more detail. The Facial Bones page

likewise shows these bones in more detail.

Atlas of the Skull More Skull Views Landmarks Cranial Bones Facial Bones

Muscular Anatomy

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 fromseveral 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 LateralViews 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 controleye 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 inthe 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.

Facial Muscles

3/4 View

Facial Muscles

Lateral Views

Tongue &

Related Muscles

Internal Jaw

Muscles



Upper Face

Muscle Details

Lower Face

Muscle Details Eye Muscles Attachments

Neuroanatomy

Neurons are specialized cells that form the brain, spinal cord, and nerve fibers. They carrymessages 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 isshown 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 sensoryinnervations 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 consciouscontrol 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.



Brainstem Nuclei

& Tracts

Diagrams of Facial

Nucleus & Nerve

Facial Nerve in

Periphery

Trigeminal Nerve

in Periphery



Motor Regions Sensory Areas Brain in Cranium Cortical

Representation

V ascular System

The vascular or circulatory system includes the arteries and veins that supply blood to the facialmuscles, both superficial and deep, and the lymphatic system that are illustrated in the panel

below.

Arteries & VeinsSuperficial

Arteries & VeinsDeep levels

Lymph

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anatomy of the human skull

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