Dermal bone

Dermal bone

A dermal bone (membrane bone)- bony structures derived from intramembranous ossification that form components of the vertebrate skeleton including the skull, jaws, gills, fins and exoskeleton. In contrast to endochondral bone, dermal bone does not form from cartilage first and then calcify. Dermal bone is formed within the dermis and it grows by accretion only; that is, the outer portion of the bone is deposited by osteocytes.

The function of dermal bone is conserved throughout vertebrates, varying in shape and numbers of bones in the skull roof and postcranial structures. In bony fish, dermal bone is found throughout the body in the fin rays and scales. Special examples of dermal bones include the clavicle, patella, and os cordis.

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  • dermal bone — any of the the superficial bones in Teleostomi derived from the dermis and overlying the deeper elements of the skull. Primitive fishes have more dermal bones than higher ones, e.g. the armour of Ostracodermi. Dermal bones are a form of membrane… …   Dictionary of ichthyology

  • dermal bone — noun Bone derived from intramembranous ossification, defining essential components of the vertebrate skeleton including the skull, jaws, gills, fins, and exoskeleton …   Wiktionary

  • dermal bone — a bone developed by ossification in the skin …   Medical dictionary

  • Bone — is the substance that forms the skeleton of the body. It is composed chiefly of calcium phosphate and calcium carbonate. It also serves as a storage area for calcium, playing a large role in calcium balance in the blood. The 206 bones in the body …   Medical dictionary

  • achondral bone — dermal bone (any of the superficial bones in Teleostomi derived from the dermis and overlying the deeper elements of the skull. Primitive fishes have more dermal bones than higher ones, e.g. the armour of Ostracodermi. Dermal bones are a form of… …   Dictionary of ichthyology

  • covering bone — dermal bone (any of the the superficial bones in Teleostomi derived from the dermis and overlying the deeper elements of the skull. Primitive fishes have more dermal bones than higher ones, e.g. the armour of Ostracodermi. Dermal bones are a form …   Dictionary of ichthyology

  • dermal basihyal — basihyal (the cartilage supporting the tongue at the anterior end of the hyal series in Elasmobranchii. It is the anteriormost median endochondral bone of the basibranchial series, joining both branches of the hyoid series and forming the tongue… …   Dictionary of ichthyology

  • dermal ossicle — noun : a small bone or concretion lying within the skin (as in various reptiles or the extinct ground sloths) …   Useful english dictionary

  • adnasal bone — a small dermal bone in front of the nasal bone in some fishes, e.g. the middle bone of three in the nasal region of Lepisosteus. Also called nasal bone …   Dictionary of ichthyology

  • Palpebral (bone) — The palpebral bone is a small dermal bone found in the region of the eye socket in a variety of animals, including crocodilians and ornithischian dinosaurs. In ornithischians, it can form a prong that projects from the front upper corner of the… …   Wikipedia

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