Search results
Results from the WOW.Com Content Network
Diagram of a typical long bone showing both compact (cortical) and cancellous (spongy) bone. Osteons on cross-section of a bone. In osteology, the osteon or haversian system (/ h ə ˈ v ɜːr. ʒ ən /; named for Clopton Havers) is the fundamental functional unit of much compact bone.
Diagram of a typical long bone showing both cortical (compact) and cancellous (spongy) bone. Haversian canals [i] (sometimes canals of Havers, osteonic canals or central canals) are a series of microscopic tubes in the outermost region of bone called cortical bone. They allow blood vessels and nerves to travel through them to supply the osteocytes.
An irregular bone is one that does not have an easily classified shape and defies description. These bones tend to have more complex shapes, like the vertebrae that support the spinal cord and protect it from compressive forces. Many facial bones, particularly the ones containing sinuses, are classified as irregular bones. [1]
Short bones are roughly cube-shaped, and have only a thin layer of compact bone surrounding a spongy interior. Short bones provide stability and support as well as some limited motion. [38] The bones of the wrist and ankle are short bones. Flat bones are thin and generally curved, with two parallel layers of compact bone sandwiching a layer of ...
Located in the main shaft of a long bone (consisting mostly of compact bone), the medullary cavity has walls composed of spongy bone (cancellous bone) and is lined with a thin, vascular membrane . [1] [2] This area is involved in the formation of red blood cells and white blood cells, and the calcium supply for bird eggshells. The area has been ...
In a disorder known as rachitis fetalis anularis the ends of the long bones (epiphyses) are enlarged. [2] Another disorder, rachitis fetalis micromelica, is a deficiency in the growth (as a shortness) of the bones. [2] There is a surgical procedure called distraction osteogenesis which is used to lengthen long bones. [3]
The appendicular skeleton, comprising the arms and legs, including the shoulder and pelvic girdles, contains 126 bones, bringing the total for the entire skeleton to 206 bones. Infants are born with about 270 bones [ 4 ] with most of it being cartilage, but will later fuse together and decrease over time to 206 bones.
The following bones develop in humans via Intramembranous ossification: [3] Flat bones of the face; Most of the bones of the skull; Clavicles; Other bone that formed by intramembranous ossification are: cortices of tubular and flat bones as well as the calvaria, upper facial bones, tympanic temporal bone, vomer, and medial pterygoid process. [4]