Anatomy

 

Osteology is the study of the bones which form the various parts of the skeleton.

The bones are joined together between them by articulations, they form the frame of the body, passive part of the locomotor apparatus whose muscles form the driving elements of them.

The bones have for certain in more one role of protection of internal organs: cranium, rib cage.

The skeleton includes/understands, a cartilagineuse part and an osseous part.

The frontal bone, (os frontis, coroaale,) situated at the anterior part of the skull, and upper part of the face, is divisible into two parts (frontal and orbital), differing in size and position: of these, one extends upwards towards the vertex, forming three-fourths of the extent of the bone; the other, inferior and horizontal in its direction, forms the roof of the orbits. To place the bone in its natural position, hold it so that the orbital plates shall look downwards, and the smooth convex surface forwards. 

Formed of two bones, the radius lateral ward ; the ulna medial ward. The two bones are joined together between them by a membrane; the inter-osseous membrane.

The adult temporal bone (French: os temporal) consists of three parts, so firmly united as to afford little trace of its complex origin. At birth the three parts are easily separable as the squamosal, petrosal, and tympanic.

In order to study the interior of the skull it is necessary to make sections in three directions, sagittal, coronal and horizontal.

The lacrimal bones (French: os lacrymal) are extremely thin and delicate, quadrilateral in shape, and situated at the anterior part of the inner wall of the orbit. They are the smallest of the facial bones.

The skull, when viewed from above, presents an oval outline; the posterior part is broader than the anterior. The bones seen in this view are the frontal, parietals and the interparietal portion of the occipital. In a skull of average width the zygomata come into view, but in very broad skulls they are obscured.

The mandible [mandibula] or lower jaw-bone is the largest and strongest bone of the face. It supports the mandibular teeth, and by means of a pair of condyles, moves on the skull at the mandibular fossae of the temporal bones. It consists of a horizontal portion — the body —  strongly curved, so as to somewhat resemble in shape a horseshoe, from the ends of which two branches or rami ascend almost at right angles.

The occipital bone, (lat.: os occipitis, french: Os occipital) is situated at the posterior part of the base of the skull; broad behind, much narrowed before, of a trapezoid figure, presenting two surfaces, four borders, and four angles. To place the bone in its natural position, hold it so that the great foramen and the articulating processes beside it shall look directly downwards; the thick process in front of the foramen will then project forwards into the base of the Skull, Whilst the broad expanded part behind it arches upwards and a little forwards, forming the posterior wall of the Cavity. 

The zygomatic [os zygomaticum] or malar bone forms the prominence known as the cheek and joins the zygomatic process of the temporal with the maxilla. It is quadrangular in form with the angles directed vertically and horizontally. The malar (or external) surface is convex and presents one or two small orifices for the transmission of the zygomatico-facial nerves and vessels. It is largely covered by the orbicularis oculi and near the middle is slightly ele- vated to form the malar tuberosity, which gives origin to the zygomaticus and zygomatic head of quadrate muscle of upper lip.

This is the u-shaped bone, so named from some resemblance to the Greek letter v. It is occasionally called the lingual bone, from its important relations with the tongue; it is situated at the base of the tongue, and may be felt between the chin and the thyroid cartilage. It consists of a body, two cornua, and two cornicula.

The nasal bones are two small oblong bones situated at the upper part of the face and forming the bridge of the nose. Each bone is thicker and narrower above, thinner and broader below, and presents for examination two surfaces and four borders.

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