skull (skul) the cranium; the bony framework of the head, composed of the cranial and facial bones.
skull
skull [skul]
skull (sk l)n. The bony or cartilaginous framework of the head, made up of the bones of the braincase and face; cranium. |   |
skull
Etymology: ME, skulle, shell
the bony structure of the head, consisting of the cranium and the skeleton of the face. The cranium, which contains and protects the brain, consists of 8 bones; the skeleton of the face is composed of 14 bones.
skull [skul]
the skeleton of the head, consisting of the cranium and the mandible. The cranium forms the domed top, back, and sides of the skull; several of its bones are large, smooth, gently curved, and connected to each other by dovetailed joints called sutures, which permit no movement and make the mature skull rigid. They protect the brain, with their curved exterior serving to deflect blows; the eyes, ears, and nose are also protected by being recessed into the skull and surrounded by bone.
At birth the skull joints are flexible, so that the infant's head can be compressed as it emerges from the birth canal. The joints remain flexible to allow expansion until the cranial bones are fully formed, around the second year of life. An infant's skull contains soft areas, or fontanels, where the bones of the cranium do not meet.
The skull is supported by the highest vertebra, called the atlas. This joint permits a back-and-forth, nodding motion. The atlas turns on the vertebra below it, the axis, which allows the skull to turn from side to side.
At birth the skull joints are flexible, so that the infant's head can be compressed as it emerges from the birth canal. The joints remain flexible to allow expansion until the cranial bones are fully formed, around the second year of life. An infant's skull contains soft areas, or fontanels, where the bones of the cranium do not meet.
The skull is supported by the highest vertebra, called the atlas. This joint permits a back-and-forth, nodding motion. The atlas turns on the vertebra below it, the axis, which allows the skull to turn from side to side.
Disorders of the Skull. The skull is rarely affected by disease. Uncommon ones like osteitis deformans and acromegaly cause the bones to increase in size. Like other bones, the skull may be fractured by blows, falls, or other accidents, but skull fracture can be far more dangerous because of its proximity to the brain.
Skull, midsagittal section. From Applegate, 2000.
skull
the bony framework of the head consisting of two parts, the cranium and the facial section.
The cranium is the domed top, back and sides of the skull that protects the brain. It is made up mostly of a roof of flat membrane bones united by sutures in the young, plus a series of cartilage bones at the base (occipital, sphenoid). Paranasal sinuses variably excavate the membrane bones.
The facial bones are mostly membrane bones and serve to support the dental arcades and the respiratory passages of the head.
skull bones
the bones of the skull are the basisphenoid, ethmoid, frontal, hyoid, incisive, interparietal, lacrimal, nasal, occipital, nasal conchal, palatine, parietal, presphenoid, pterygoid, sphenoid, temporal, vomer and zygomatic.
brachycephalic skull
short, broad skull.
dolicocephalic skull
long, narrow skull.
mesaticephalic skull
a medium skull in terms of width and length.
skull symmetry
asymmetry common only in foals in which the lower part of the face is deviated to one side, involving mandibles, maxillae and nasal bones.
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