Facial Skull

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BiologyFacial and Abdomen

Febrian Adhi Pratama



Facial Skull

The skull is additionally comprised of fourteen bones which make up the face. The facial bones do not touch the brain but are still considered part of the skull. Some cranial bones meet with the

facial bones to give each individual a varying form, the frame work from which the face is then built upon. Additionally, facial bones provide an anchor for the teeth and provide a structure for

the muscles of the face and jaw to attach. All bones of the face are structured in pairs, except themandible and the vomer.

Maxilla

The maxillas, or maxillae when referencing two, join together at the center in order to form the

upper jaw and provide structure for the upper teeth. The alveolar process is part of eachindividual maxilla, which anchors the molars, pre-molars, incisors, and cuspids. The roof of the

mouth is formed by a hard plate known as the palatine process. Just in front of this hard plate but behind the incisors lies the incisive foramen. The infraorbital nerve and the artery that leads to

the nose pass through the infraorbital foramen, which fits snugly under each orbit.



The inferior orbital fissure is the last opening within the maxilla. It creates the opening the

allows passage of the maxillary nerve and the and the infraorbital vessels, and it is located between the sphenoid wing and the maxilla. The maxilla bone also creates one of the four basic

chambers of the paranasal cavity, often referred to as the maxillary sinus.

Palatine Bone

The palatine bones are responsible for contributing to the shape of the rear third of the roof of the

mouth, a portion of the orbits, as well as a portion of the nasal cavity. The hard palate is made upin part by the horizontal plates of the palatine bone. The palatine foramen is located at the

posterior angle and contributes to the formation of the greater palatine foramen which allows passage for the greater palatine nerve as well as the palatine vessels. The lesser palatine foramina

follow the greater palatine foramina, creating a passageway which allows the lesser palatinenerves to pass through.



Zygomatic Bone

The zygomatic bones are commonly called the cheekbones, and they are responsible for formingthe lateral contour of the facial structure. The zygomatic arch is formed by the meeting of the

zygomatic process as well as temporal process which extends to meet with the zygomatic process. The lateral ridge of the orbit is also formed in part by the zygomatic bones. The

zygomatic nerves and vessels are permitted passage through the zygomaticofacial foramen,which is on the surface of the bone.

Lacrimal Bone

The lacrimal bones are thin bones that form the anterior portion of the medial walls of the

individual orbits. These bones serve as structural additions for the eye sockets. The tiniest of allthe facial bones, each individual lacrimal bone contains a groove that assists in forming the

nasolacrimal canal. This groove is known as lacrimal sulcus. The nasolacrimal canal is the passageway in the facial bones which allows the tears from the eye to drain into the nasal cavity.



Nasal Bone

At the midline, in nearly the center of the facial structure, a small triangular formation of nasal

bones forms the basic structure for the nose. The bones do not extend fully forward, as most of the nose is constructed from cartilage, however this bone formation lays the foundation for the

cartilage to extend from as well as forms a solid structured opening to allow for an airway. Thenasal bones simply support the plates of cartilage which form the nose. Fractures to the nose are

often fractures of the cartilage as it is very difficult to experience impact that would break thenasal bones.



Inferior Nasal Concha

The fragile bones in the shape of a scroll that reside in the lateral walls of the nasal cavity arecovered in mucous membranes in order to help warm and moisten the oxygen inhaled through

the nostrils. The inferior nasal choncha are similar to the other concha, but are smaller and project horizontally and medially from the walls of the nasal cavity. They protrude below both

the superior and middle nasal conchae of which belong to the ethmoid bone. All three sets of concha bones cleanse the air as it enters the nasal cavity.



V omer

The vomer is one of only two bones in the face that is a solitary bone, lacking an identical,

opposing bone on the opposite side of the face. Forming the lower section of the septum, this bone is flat and nearly paper thin. In conjunction with the perpendicular plate of the ethmoid

bone, it is responsible for assisting in the support of the septal cartilage. The septal cartilage is

part of the formation of the front and inside portions of the nasal septum.



Mandible

The mandible is the largest of all the facial bones and is the only bone of the facial bones that has

the ability of movement. The mandible is able to create movement such as this through two joints which attach it to the skull known as temporomandibular joints. The body of the mandible,

which is comprised of the front and sides, creates the shape of a horseshoe. Two rami extendfrom the mandible at the exterior portion. Each individual ramus contains a knoblike condylar

processes that are located reside at the superior margin. The condylar process meets the

mandibular fossa of the temporal bone. A pointed coronoid process extends to allow for attachment of the temporalis muscle. The mandibular notch is the depressed area that exists between the two processes. At the corner of the jaw, where the vertical ramus and the horizontal

body meet, is the angle of the mandible.



Two sets of foramina, the mental foramen and the mandibular foramen, allow for the passage of nerves. The mental foramen is located on the mandible at the anterolateral aspect of the body of

the mandible. This is located before the first molar. The mandibular foramen is located on themedial surface of the ramus. The mental foramen allows the passage of the mental nerve and the

mandibular foramen allows for passage of the inferior alveolar nerves and vessels.

There are a variety of muscle which attach from the skull to the mandible to allow for themovement of the jaw. The mandible is design to hold the 16 lower teeth that align with the 16

upper teeth supported by the skull.

Hyoid BoneThe hyoid bone is a very unique bone, solitary in design, and is the only bone in the human body

that does not attach in any form to any other bone. The hyoid bone is located below the mandibleand is suspended in the neck by the styloid process, which is part of the temporal bone, as well as

the stylohoid muscles and ligaments. The hyoid bone consists of its body, two posteriorly projecting greater cornua which attach to the ligaments, and two lesser cornua which extend

toward to anterior. The hyoid bone is responsible for the support necessary for the tongue as wellas serving as an attachment point for some of the tongue¶s muscles. If a thumb and forefinger is



placed on the neck, under the lateral portions of the mandible, and a gentle pressure is applied,the hyoid bone can be palpated. This little bone almost always breaks during strangulation and is

a vital piece of information when performing an autopsy.

Muscles involving facial expression

The human face is well designed for a vast array of facial movements and expressions.Expression is part of the human means of social communication. This technique allows for

communication of feelings and even sometimes thoughts without the assistance of words. The

muscles which allow this complex communication through various expressions are located insuperficial positions along the face, the scalp, and the neck.



Choosing from the three layered muscles of the lateral abdominal wall, the external abdominal oblique

remains the most superficial yet ironically the strongest. The fibers of the muscle are directed medially

and inferiorly to amplify its contraction. Buried deep to the external abdominal oblique is the internal

abdominal oblique muscle. The muscles fibers of the internal oblique are designed to lay at right angles

to those of the external oblique, creating a strong structural and functional unison between the two

muscles.

The deepest of the muscles of the abdomen is the transversus abdominis. The long fibers of this muscle

are put to use across the abdominal wall, laterally.

A large sheath encases the long rectus abdominis in its entirety. This strap-like muscle remains encasedin a fibrous sheath created by aponeuroses that comes from the fibers of the other three muscles of the

abdominal wall.

Segregated the two rectus abdominins muscles is a band of connective tissue called the linea alba,

running the entire midline region of the abdominal wall. The appearance of abs, the segmented

muscle ripple of a human with good muscle tone and low body fat in the abdominal region, is created by

tendons which transect the abdomen horizontally.

Facial Skull

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