An irregular unpaired bone situated at the SKULL BASE and wedged between the frontal, temporal, and occipital bones (FRONTAL BONE; TEMPORAL BONE; OCCIPITAL BONE). Sphenoid bone consists of a median body and three pairs of processes resembling a bat with spread wings. The body is hollowed out in its inferior to form two large cavities (SPHENOID SINUS).
Cranial Fossa, Middle
The compartment containing the anterior extremities and half the inferior surface of the temporal lobes (TEMPORAL LOBE) of the cerebral hemispheres. Lying posterior and inferior to the anterior cranial fossa (CRANIAL FOSSA, ANTERIOR), it is formed by part of the TEMPORAL BONE and SPHENOID BONE. It is separated from the posterior cranial fossa (CRANIAL FOSSA, POSTERIOR) by crests formed by the superior borders of the petrous parts of the temporal bones.
Bone and Bones
Tomography, X-Ray Computed
Paranasal Sinus Diseases
Cerebrospinal Fluid Rhinorrhea
Magnetic Resonance Imaging
The continuous turnover of BONE MATRIX and mineral that involves first an increase in BONE RESORPTION (osteoclastic activity) and later, reactive BONE FORMATION (osteoblastic activity). The process of bone remodeling takes place in the adult skeleton at discrete foci. The process ensures the mechanical integrity of the skeleton throughout life and plays an important role in calcium HOMEOSTASIS. An imbalance in the regulation of bone remodeling's two contrasting events, bone resorption and bone formation, results in many of the metabolic bone diseases, such as OSTEOPOROSIS.
The amount of mineral per square centimeter of BONE. This is the definition used in clinical practice. Actual bone density would be expressed in grams per milliliter. It is most frequently measured by X-RAY ABSORPTIOMETRY or TOMOGRAPHY, X RAY COMPUTED. Bone density is an important predictor for OSTEOPOROSIS.
It is a form of protection provided by law. In the United States this protection is granted to authors of original works of authorship, including literary, dramatic, musical, artistic, and certain other intellectual works. This protection is available to both published and unpublished works. (from Circular of the United States Copyright Office, 6/30/2008)
Protective measures against unauthorized access to or interference with computer operating systems, telecommunications, or data structures, especially the modification, deletion, destruction, or release of data in computers. It includes methods of forestalling interference by computer viruses or so-called computer hackers aiming to compromise stored data.
A light and spongy (pneumatized) bone that lies between the orbital part of FRONTAL BONE and the anterior of SPHENOID BONE. Ethmoid bone separates the ORBIT from the ETHMOID SINUS. It consists of a horizontal plate, a perpendicular plate, and two lateral labyrinths.
Either of a pair of compound bones forming the lateral (left and right) surfaces and base of the skull which contains the organs of hearing. It is a large bone formed by the fusion of parts: the squamous (the flattened anterior-superior part), the tympanic (the curved anterior-inferior part), the mastoid (the irregular posterior portion), and the petrous (the part at the base of the skull).