bone

Bône:

see AnnabaAnnaba
, formerly Bône
(bōn), city (1998 pop. 348,554), capital of Annaba prov., extreme NE Algeria, a port on the Mediterranean Sea. One of the country's leading ports, the city is also an important administrative, commercial, and industrial center.
..... Click the link for more information. , Algeria.

bone,

hard tissue that forms the skeletonskeleton,
in anatomy, the stiff supportive framework of the body. The two basic types of skeleton found among animals are the exoskeleton and the endoskeleton. The shell of the clam is an exoskeleton composed primarily of calcium carbonate.
..... Click the link for more information. of the body in vertebrate animals. In the very young, the skeleton is composed largely of cartilage and is therefore pliable, reducing the incidence of bone fracture and breakage in childhood. The inorganic, or mineral, content of bone is mainly calcium, phosphate and carbonate minerals. The organic content is a gelatinous material called collagen. As the body grows older, decreases in bone mass may lead to an increased vulnerability to fractures. Bone fractures heal naturally, although they are often aided through restriction of movement in the affected area. Bones assume a variety of sizes and shapes; however, all bone tissue has a three-layered composition. A spongy layer forms the interior. Long bones (such as those in the arms and legs) are hollow, the inner spaces being filled with marrow (see bone marrowbone marrow,
soft tissue filling the spongy interiors of animal bones. Red marrow is the principal organ that forms blood cells in mammals, including humans (see blood). In children, the bones contain only red marrow.
..... Click the link for more information. ), important in the formation of blood cells. Surrounding the spongy, inner layer is a hard, compact layer that functions as the basic supportive tissue of the body. The outer layer is a tough membrane called the periosteum, which sheaths most bones. Although bone appears solid, it contains numerous microscopic canals permitting the passage of blood vessels and nerve fibers. Two types of bone are present in most bones: compact, which constitutes the shaft, and cancellous, an extremely strong variety which makes up the enlarged ends of the bone. See also osteoporosisosteoporosis
, disorder in which the normal replenishment of old bone tissue is severely disrupted, resulting in weakened bones and increased risk of fracture; osteopenia results when bone-mass loss is significant but not as severe as in osteoporosis.
..... Click the link for more information. .

Bone

The hard connective tissue that, together with cartilage, forms the skeleton of humans and other vertebrates. It is made of calcium phosphate crystals arranged on a protein scaffold. Bone performs a variety of functions: it has a structural and mechanical role; it protects vital organs; it provides a site for the production of blood cells; it serves as a reserve of calcium. See Connective tissue

There are two types of bone in the skeleton: the flat bones (for example, the bones of the skull and ribs) and the long bones (for example, the femur and the bones of the hand and feet). Both types are characterized by an outer layer of dense, compact bone, known as cortical bone, and an inner spongy bone material made up of thin trabeculae, known as cancellous bone. Cortical bone consists of layers of bone (lamellae) in an orderly concentric cylindrical arrangement around tiny Haversian canals. These interconnecting canals carry the blood vessels, lymph vessels, and nerves through the bone and communicate with the periosteum and the marrow cavity. The periosteum is a thin membrane covering the outer surface of bone and consisting of layers of cells that participate in the remodeling and repair of bone. The cancellous bone is in contact with the bone marrow, in which much of the production of blood cells takes place. The interface between the cancellous bone and the marrow is called the endosteum, and it is largely at this site that bone is removed in response to a need for increased calcium elsewhere in the body.

Bone is formed by the laying down of an osteoid matrix by osteoblasts, the bone-forming cells, and the mineralization of the osteoid by the development and deposition of crystals of calcium phosphate (in the form of hydroxyapatite) within it. It is the mineral, organized in a regular pattern on a collagen scaffold, that gives bone its stiffness. Osteoid contains largely fibers of type I collagen and lesser amounts of numerous noncollagenous proteins. Although the role of these proteins in bone is not well understood, it is thought that their particular combination in bone gives this tissue the unique ability to mineralize. It is clear that these proteins interact with each other and that collagen and several of the noncollagenous proteins can bind to specialized receptors on the surface of bone cells. This binding is important for the adhesion of the cells to the bone matrix, and also delivers behavioral signals to the cells. See Collagen

The primary cell types in bone are those that result in its formation and maintenance (osteoblasts and osteocytes) and those that are responsible for its removal (osteoclasts). Osteoblasts form from the differentiation of multipotential stromal cells that reside in the periosteum and the bone marrow. Under the appropriate stimuli, these primitive stromal cells mature to bone-forming cells at targeted sites in the skeleton. Under different stimuli, they are also capable of developing into adipocytes (fat cells), muscle cells, and chondrocytes (cartilage cells). Osteocytes, which are osteoblasts that become incorporated within the bone tissue itself, are the most numerous cell type in bone. They reside in spaces (lacunae) within the mineralized bone, forming numerous extensions through tiny channels (cannaliculi) in the bone that connect with other osteocytes and with the cells on the endosteal surface. Osteocytes are therefore ideally placed to sense stresses and loads placed on the bone and to convey this information to the osteoblasts on the bone surface, thus enabling bone to adapt to altered mechanical loading by the formation of new bone. Osteocytes are also thought to be the cells that detect and direct the repair of microscopic damage that frequently occurs in the bone matrix due to wear and tear. Failure to repair the cracks and microfractures that occur in bone, or when this microdamage accumulates at a rate exceeding its repair, can cause the structural failure of the bone, such as in stress fractures. A large number of molecules that regulate the formation and function of osteoblastic cells have been identified. Circulating hormones, such as insulin, growth hormone, and insulinlike growth factors, combine with growth factors within the bone itself, such as transforming growth factor beta (TGFβ) and bone morphogenetic proteins (BMPs), to influence the differentiation of osteoblasts.

Osteoclasts are typically large, multinucleated cells, rich in the intracellular machinery required for bone resorption. This is accomplished when the cells form a tight sealing zone by attachment of the cell membrane against the bone matrix, creating a bone-resorbing compartment. Into this space, the cell secretes acid to dissolve the bone mineral, and enzymes to digest the collagen and other proteins in the bone matrix. The removal of bone by osteoclasts is necessary to enable the repair of microscopic damage and changes in bone shape during growth and tooth eruption. Osteoclast-mediated bone resorption is also the mechanism for releasing calcium stored in bone for the maintenance of calcium levels in the blood. Most agents that promote bone resorption act on osteoblastic cells, which in turn convey signals to osteoclast precursors to differentiate into mature osteoclasts. These agents include the active form of vitamin D, parathyroid hormone, interleukin-1, interleukin-6, and interleukin-11, and prostaglandins such as prostaglandin E₂. Differentiation to fully functional osteoclasts also requires close contact between osteoclast precursors and osteoblastic cells. This is due to a molecule called osteoclast differentiation factor (ODF) which is located on the surface of osteoblasts, binds to receptors on the surface of osteoclast precursor cells, and induces their progression to osteoclasts.

Flat bones and long bones are formed by different embryological means. Formation of flat bones occurs by intramembranous ossification, in which primitive mesenchymal cells differentiate directly into osteoblasts and produce bony trabeculae within a periosteal membrane. The initial nature of this bone is relatively disorganized and is termed woven bone. Later, this woven bone is remodeled and replaced by the much stronger mature lamella bone, consisting of layers of calcified matrix arranged in orderly fashion. Long bones are formed by intracartilaginous development in which the future bone begins as cartilage. The cartilage template is gradually replaced by bone in an orderly sequence of events starting at the center of the growing bone. Cartilage remains at the ends of long bones during growth, forming a structure at each end termed the growth plate. Cartilage cells (chondrocytes) that arise in the growth plates proliferate and add to the length of the bone. This occurs during a complex series of events, with expansion both away from and toward the center of the bone. When the bone achieves its final length in maturity, expansion from the growth plate ceases. Cartilage persists at the ends of the long bones in a specific form called articular cartilage, which provides the smooth bearing surfaces for the joints.

Bone is a dynamic tissue and is constantly being remodeled by the actions of osteoclasts and osteoblasts. After bone removal, the osteoclasts either move on to new resorption sites or die; this is followed by a reversal phase where osteoblasts are attracted to the resorption site. It is thought that growth factors that are sequestered in an inactive form in the bone matrix are released and activated by the osteoclast activity and that these in turn promote fresh osteoid production by the recruited osteoblasts. The new osteoid eventually calcifies, and in this way the bone is formed and replaced in layers (lamellae), which are the result of these repeated cycles. In growing bone, the activities of bone cells is skewed toward a net increase in bone. However, in healthy mature bone there is an equilibrium between bone resorption and bone formation. When the equilibrium between these two cell types breaks down, skeletal pathology results.

The most common bone disease is osteoporosis, in which there is a net loss of bone due to osteoclastic bone resorption that is not completely matched by new bone formation. The best-understood cause of osteoporosis is that which occurs in women due to the loss of circulating estrogen after menopause. Another cause of osteoporotic bone loss is seen in disuse osteoporosis. Just as bone can respond to increased loading with the production of additional bone, bone is also dependent on regular loading for its maintenance. Significant bone loss can occur during prolonged bed rest or, for example, in paraplegia and quadriplegia. Likewise, an unloading of the skeleton (due to a lack of gravitational pull) in space flight results in severe bone loss in astronauts unless the effects of gravity are simulated by special exercises and devices. See Osteoporosis

Many metabolic and genetic diseases can affect the amount and quality of bone. Metabolic diseases such as diabetes, kidney disease, oversecretion of parathyroid hormone by the parathyroid glands, anorexia nervosa, and vitamin D-dependent rickets may cause osteopenias (the reduction in bone volume and bone structural quality). Immunosuppressive therapy in organ transplant patients can lead to reduced bone mass, as can tumors of bone and other sites. Tumors can produce substances that cause the activation of osteoclastic bone resorption. In the genetically based disease osteogenesis imperfecta, mutations in the gene for type I collagen result in the production of reduced amounts of collagen or altered collagen molecules by osteoblasts. Other common diseases of the skeleton are diseases of the joints, such as rheumatoid arthritis and osteoarthritis. See Thyroid gland

Bone

the principal element of the vertebrate skeleton.

Bones, the joints and ligaments joining the skeletal bones, and the muscles attached to the bones by tendons together make up the locomotor apparatus. Bones are classified as long, or tubular (for example, the humerus and the femur), flat (for example, the bones of the skull), or short (for example, the vertebrae). The middle section of the long bones is called the diaphysis. The two ends are called the epiphyses. The articulations are either immobile (synarthroses; for example, cranial sutures) or mobile (joints, or diarthroses; for example, the articulations of the limbs).

Bones consist of bony tissue, periosteum, marrow, blood and lymphatic vessels, nerves, and, in many cases, cartilage. Bony tissue, the main constituent, forms lamellae; the bone is considered compact or cancellous (spongy) according to the density of these lamellae. In long bones, the shaft is predominantly of the compact type of bony tissue, where the arrangement of lamellae depends chiefly on the distribution of the bone-feeding blood vessels in the haversian canals. In short bones and in the epiphyses of long bones, cancellous tissue is predominant; here,

Table 1. Classification of boiler units according to parameters and output
	Parameters of superheated steam			Rated steam output (tons/hr)
	Pressure (MN/m² [kgf/cm²])	Temperature (°C)
	Pressure (MN/m² [kgf/cm²])	Primary superheated steam	Secondary superheated steam
Unit with natural circulation, with and without superheating. . . . . . . . . .	4 (40)	440	—	6.5, 10, 15, 20, 25, 35, 50, 75
	10 (100)	540	—	60, 90, 120, 160, 220
	14 (140)	570	—	160, 210, 320, 420, 480
Unit with natural circulation, with superheating and intermediate superheating of steam. . . . . . . . . .	14 (140)	570	570	320, 500, 640
Flow-through unit with superheating and intermediate superheating of steam. . . . . . . . . .	25.5 (255)	585-565	570	950; 1,600; 2,500

there are honeycomblike cavities, filled with marrow, between the lamellae or trabeculae. The trabeculae are arranged in the direction of greatest pressure and tension, ensuring maximum tensile strength with a minimum of material. Bones are covered with periosteum, which contains blood vessels and nerves. Bone is a variety of connective tissue. Insoluble salts (chiefly hydroxylapatite) constitute about 50 percent of its bulk.

Bone cells, or osteocytes, lie embedded in the bone cavities (lacunae). They are linked to one another by thin processes in the canaliculi, through which they are supplied with nutrients. The intercellular substance of bony tissues consists of tightly packed collagen fibers (on the surface of which are hydroxylapatite crystals), polysaccharides, and proteins. The formation and calcification of the intercellular substance are brought about by osteoblasts, which become embedded in the intercellular substance during the course of osteogenesis (to become the osteocytes).

Bony tissue is the body’s main calcium depot, and it is active in calcium metabolism. Calcium is released by the resorption and bound by the formation of bony tissue. These processes occur during the reconstruction of bony tissue, which occurs constantly and throughout life.

The shape of bone changes with changing mechanical loads. Bony tissue in the human skeleton is almost completely reconstructed every ten years; multinuclear cells called osteoclasts are involved in the resorption.

Bone is classified as coarse-fibrous or fine-fibrous (lamellate) according to the arrangement of the collagen fiber in the ground substance. In coarse-fibrous bone the fibers are arranged randomly, but in fine-fibrous bone they form plates, or lamellae, in which most of the fibers are arranged in the same direction.

Bones develop either from the embryonic connective tissue, mesenchyma, or directly (secondary, or cover, bone, such as the frontal and parietal bones), or by passing through a cartilaginous stage (primary, or substitution, bone, such as the humerus and the femur). Secondary bone, in terms of vertebrate evolution, developed from dermal scales that sank beneath the skin; primary bone originated as an ossification of cartilaginous endo-skeleton. The development of secondary bone involves the formation of a skeletogenous rudiment, a collection of mesenchymal cells that eventually become osteoblasts and form bone. In the development of primary bone, the initial formation in the skeletogenous rudiment is a cartilaginous model of the future bone. The model is replaced subsequently by bony tissue, and the cartilage disintegrates. The coarse-fibrous bone formed in the rudiment is replaced by fine-fibrous bone in some amphibians and reptiles, most birds, and mammals.

The process of bone formation usually intensifies dramatically when a tubular bone is fractured. A chondro-osseous callus forms to reunite the fragments. The shape of the bone is restored in the course of further reconstruction. Bone can form in adult vertebrates, including man, not only as part of the skeleton but also in any connective tissue (ectopic osteogenesis).

REFERENCES

Zavarzin, A. A., and A. V. Rumiantsev. Kurs gistologii, 6th ed., chapter 6. Moscow, 1946.
Ivanov, G. F. Osnovy normal’noi anatomii cheloveka, vols. 1–2. Moscow, 1949.
Fridenshtein, A. la. Experimental’noe vneskeletnoe kosteoobrazovanie. Moscow, 1963.

A. IA. FRIDENSHTEIN

What does it mean when you dream about bones?

Bones can obviously represent death, either literal or metaphorical. They can also symbolize a state of reduction or deprivation (as in being “stripped to the bare bones” and being left with a “skeleton crew”). Less ominously, bones may simply refer to the structure of something.

bone

[bōn] (anatomy) One of the parts constituting a vertebrate skeleton. (histology) A hard connective tissue that forms the major portion of the vertebrate skeleton.

bone

1. any of the various structures that make up the skeleton in most vertebrates 2. the porous rigid tissue of which these parts are made, consisting of a matrix of collagen and inorganic salts, esp calcium phosphate, interspersed with canals and small holes

bone

[bōn] 1. the hard, rigid form of connective tissue constituting most of the skeleton of vertebrates, composed chiefly of calcium salts.2. any distinct piece of the skeleton of the body. See anatomic Table of Bones in the Appendices for regional and alphabetical listings of bones, and see color plates 1 and 2. Called also os. adj., adj bo´ny.
There are 206 separate bones in the human body. Collectively they form the skeletal system, a structure bound together by ligaments at the joints and set in motion by the muscles, which are secured to the bones by means of tendons. Bones, ligaments, muscles, and tendons are the tissues of the body responsible for supporting and moving the body.
Some bones have a chiefly protective function. An example is the skull, which encloses the brain, the back of the eyeball, and the inner ear. Some, such as the pelvis, are mainly supporting structures. Other bones, such as the jaw and the bones of the fingers, are concerned chiefly with movement. The marrow" >bone marrow in the center manufactures blood cells. The bones themselves act as a storehouse of calcium, which must be maintained at a certain level in the blood for the body's normal chemical functioning. Structure and Composition. Bone is not uniform in structure but is composed of several layers of different materials. The outermost layer, the periosteum, is a thin, tough membrane of fibrous tissue. It gives support to the tendons that secure the muscle to the bone and also serves as a protective sheath. This membrane encloses all bones completely except at the joints where there is a layer of cartilage. Beneath the periosteum lie the dense, hard layers of bone tissue called compact bone. Its composition is fibrous rather than solid and it gives bone its resiliency. Encased within these layers is the tissue that makes up most of the volume of bone, called cancellous or spongy bone because it contains little hollows like those of a sponge. The innermost portion of the bone is a hollow cavity containing marrow. Blood vessels course through every layer of bone, carrying nutritive elements, oxygen, and other products. Bone tissue also contains a large number of nerves. The basic chemical in bone, which gives bone its hardness and strength, is calcium phosphate. Development. Cartilage forms the major part of bone in the very young; this accounts for the great flexibility and resiliency of the infant skeleton. Gradually, calcium phosphate collects in the cartilage, and it becomes harder and more brittle. Some of the cartilage cells break loose, so that channels develop in the bone shaft. Blood vessels enter the channels, bearing with them small cells of connective tissue, some of which become osteoblasts, cells that form true bone. The osteoblasts enter the hardened cartilage, forming layers of hard, firm bone. Other cells, called osteoclasts, work to tear down old or excess bone structure, allowing the osteoblasts to rebuild with new bone. This renewal continues throughout life, although it slows down with age.
Cartilage formation and the subsequent replacement of cartilage by hard material is the mechanism by which bones grow in size. During the period of bone growth, cartilage grows over the hardened portion of bone. In time, this layer of cartilage hardens as calcium phosphate is added, and a fresh layer grows over it, and it too hardens. The process continues until the body reaches full growth. Long bones grow in length because of special cross-sectional layers of cartilage located near the flared ends of the bone. These harden and new cartilage is produced by the same process as previously described. Bone Disorders. fracture, a break in the bone, is the most common injury to the bone; it may be closed, with no break in the skin, or open, with penetration of the skin and exposure of portions of the broken bone. osteoporosis is excessive brittleness and porosity of bone in the aged. osteomyelitis is a bone infection similar to a boil on the skin, but much more serious because blood supply to bone is less exquisite than that to other body organs and bone metabolizes more slowly, so that the infection can destroy the bone and invade other body tissues. osteomalacia is the term used for rickets when it occurs in adults. In these diseases there is softening of the bones, due to inadequate concentration of calcium or phosphorus in the body. The usual cause is deficiency of vitamin D, which is required for utilization of calcium and phosphorus by the body. In osteitis fibrosa cystica, bone is replaced by fibrous tissue because of abnormal calcium metabolism. The condition usually is due to overactivity of the parathyroid glands. osteoma refers to abnormal new growth, either benign or malignant, of the tissue of the bones. Although it is not common, it may occur in any of the bones of the body, and at any age.alveolar bone the thin layer of bone making up the bony processes of the maxilla and mandible, surrounding and containing the teeth; it is pierced by many small blood vessels, lymphatic vessels, and nerves.ankle bone talus.brittle b's osteogenesis imperfecta.bundle bone lamina dura.cancellated bone (cancellous bone) bone composed of thin intersecting lamellae, usually found internal to compact bone.cartilage bone bone developing within cartilage, ossification taking place within a cartilage model, as opposed to membranous bone.cheek bone zygomatic bone.collar bone clavicle.compact bone bone substance that is dense and hard.cortical bone the compact bone of the shaft of a bone that surrounds the marrow cavity.cranial b's the bones that constitute the cranium, including the occipital, sphenoid, temporal, parietal, frontal, ethmoid, lacrimal, and nasal bones, the inferior nasal concha, and the vomer. Some authorities also include the maxilla, zygomatic bone, and palatine bone. See anatomic Table of Bones in the Appendices.ethmoid bone the sievelike bone that forms a roof for the nasal fossae and part of the floor of the anterior cranial fossa. See anatomic Table of Bones in the Appendices.facial b's the bones that form the skeleton of the face, including the hyoid, palatine, and zygomatic bones, the mandible, and the maxilla. Some authorities include the lacrimal bones, nasal bones, inferior nasal concha, and vomer and exclude the hyoid bone. See anatomic Table of Bones in the Appendices.flat bone one whose thickness is slight, sometimes consisting of only a thin layer of compact bone, or of two layers with intervening cancellous bone and marrow; usually curved rather than flat.frontal bone the bone at the anterior part of the skull. See anatomic Table of Bones in the Appendices.heel bone calcaneus.hip bone the ilium, ischium, and pubis as a unit. See anatomic Table of Bones in the Appendices.hyoid bone a horseshoe-shaped bone at the base of the tongue. See anatomic Table of Bones in the Appendices. Called also lingual bone.incisive bone the portion of the maxilla bearing the incisors; developmentally, it is the premaxilla, which in humans later fuses with the maxilla, but in most other vertebrates persists as a separate bone.innominate bone hip bone.jaw bone either the mandible (lower jaw) or the maxilla (upper jaw). See anatomic Table of Bones in the Appendices.jugal bone zygomatic bone.lingual bone hyoid bone.long bone one whose length far exceeds its breadth and thickness.malar bone zygomatic bone.marble b's osteopetrosis.mastoid bone part of temporal bone" >mastoid part of temporal bone.membrane bone (membranous bone) bone that develops within a connective tissue membrane, in contrast to cartilage bone.occipital bone the bone constituting the back and part of the base of the skull. See anatomic Table of Bones in the Appendices.parietal bone one of two bones forming the sides and roof of the cranium. See anatomic Table of Bones in the Appendices.pelvic bone hip bone.petrous bone part of temporal bone" >petrous part of temporal bone.pneumatic bone bone that contains air-filled spaces.premaxillary bone premaxilla.pterygoid bone pterygoid process.rider's bone localized ossification sometimes seen on the inner aspect of the lower end of the tendon of the adductor muscle of the thigh in horseback riders.shin bone tibia.short bone one of approximately equal length, width, and thickness.solid bone compact bone.spongy bone cancellous bone.squamous bone part of temporal bone" >squamous part of temporal bone.sutural bone any of the variable and irregularly shaped bones in the sutures between the bones of the skull. Called also wormian bone.temporal bone one of two bones forming part of the lateral and inferior surfaces of the skull and containing the organs of hearing. See anatomic Table of Bones in the Appendices.thigh bone femur.turbinate bone a nasal concha.tympanic bone part of temporal bone" >tympanic part of temporal bone.wormian bone sutural bone.zygomatic bone the quadrilateral bone that forms a cheek. See anatomic Table of Bones in the Appendices.

bone

(bōn), [TA] A hard connective tissue consisting of cells embedded in a matrix of mineralized ground substance and collagen fibers. The fibers are impregnated with inorganic components, including crystals of calcium phosphate, such that using X-ray defraction, they are seen to be organized in a hydroxyapatite pattern (calcium phosphate is 85% by weight) as well as calcium carbonate (10%), and magnesium; by weight, bone is composed of 65-75% inorganic and 25-35% organic material; a portion of osseous tissue of definite shape and size, forming a part of the animal skeleton; in humans there are approximately 200 distinct bones in the skeleton, not including the auditory ossicles of the tympanic cavity or the sesamoid bones other than the two patellae. A bone is enveloped by a fibrous membrane, periosteum, that covers the bone's entire surface except for the articular cartilage. Beneath the periosteum is a dense layer, compact bone, and beneath that a cancellous layer, spongy bone. The core of a long bone is filled with marrow. Synonym(s): os [TA] [A.S. bān]

bone

(bōn)n.1. a. The dense, semirigid, porous, calcified connective tissue forming the major portion of the skeleton of most vertebrates. It consists of a dense organic matrix and an inorganic, mineral component.b. Any of numerous anatomically distinct structures making up the skeleton of a vertebrate animal. There are more than 200 different bones in the human body.c. A piece of bone.2. bonesa. The skeleton.b. The body: These old bones don't do much dancing anymore.c. Mortal remains: His bones are buried up on the hill.3. An animal structure or material, such as ivory, resembling bone.4. Something made of bone or of material resembling bone, especially:a. A piece of whalebone or similar material used as a corset stay.b. bones Informal Dice.5. bones The fundamental plan or design, as of the plot of a book.6. a. bones Flat clappers made of bone or wood originally used by the end man in a minstrel show.b. Bones(used with a sing. verb) The end man in a minstrel show.7. Vulgar Slang The penis.v. boned, boning, bones v.tr.1. To remove the bones from: bone a fish.2. To stiffen (a piece of clothing) with stays, as of whalebone.3. Vulgar Slang To have sexual intercourse with. Used especially of a man.v.intr. Vulgar Slang To have sexual intercourse.

bone

adjective Bony, osseous; referring to bone.

Anatomy
noun A solid, rigid, ossified connective tissue forming an organ of the skeletal system; any of the 206 bones in the body.
Drug slang
noun A regional street term for:
(1) Marijuana;
(2) A large rock of crack cocaine.
Histology
The indurated, calcified vertebrate tissue, which consists of calcium carbonate, calcium phosphate and ground substance; bone stores calcium, playing a central role in the body’s calcium balance.

bone

Anatomy A solid, rigid, ossified connective tissue forming an organ of the skeletal system; any of the 206 bones in the body. See Basisphenoid bone, Blue bone, Carpal bone, Cancellous bone, Compact bone, Cuboid bone, Cuneiform bone, Disappearing bone, Dumbbell bone, Endochondral bone, Facial bone, Frontal bone, Funny bone, Halbard bone, Hetereotopic bone, Hungry bone, Hyoid bone, Innominate bone, Lacrimal bone, Membranous bone, Moth-eaten bone, Nasal bone, Navicular bone, Peppermint stick candy bone, Ping pong bone, Red bone, Rider's bone, Shooter bone, Spongy bone, Wormian bone, Woven bone, Zygomatic bon.

bone

(bōn) [TA] 1. A hard connective tissue consisting of cells embedded in a matrix of mineralized ground substance and collagen fibers. The fibers are impregnated with a form of calcium phosphate similar to hydroxyapatite as well as with substantial quantities of carbonate, citrate, sodium, and magnesium; by weight, bone is composed of 75% inorganic material and 25% organic material. 2. A portion of osseous tissue of definite shape and size, forming a part of the animal skeleton; in human adults there are approximately 200 distinct bones in the skeleton, not including the auditory ossicles of the tympanic cavity or the sesamoid bones other than the two patellae. A bone is enveloped by a fibrous membrane, periosteum, that covers the bone's entire surface except for the articular cartilage. Beneath the periosteum is a denselayer, compact bone, and beneath that a cancellous layer, spongy bone. The core of a long bone is filled with marrow.
Synonym(s): os [TA] . [A.S. bān]

bone

(bon) 1. Osseous tissue, a specialized form of dense connective tissue consisting of bone cells (osteocytes) embedded in a nonliving matrix. Bone matrix is made of calcium carbonate, calcium phosphate, and collagen fibers. Synonym: os.

PARTS OF A LONG BONE2. A unit of the skeleton; the human skeleton has 206 bones. Bones surround and protect some vital organs, and give points of attachment for the muscles, serving as levers and making movement possible. In the embryo, the bones of the skull are first made of fibrous connective tissue, which is gradually replaced by bone matrix. The remainder of the skeleton is first made of hyaline cartilage, which is also replaced by bone matrix, beginning during the third month of gestation. The outer surface of a bone is compact bone, and the inner more porous portion is cancellous (spongy) bone. The shafts of long bones are made of compact bone that surrounds a marrow canal. Compact bone is made of haversian systems, which are precise arrangements of osteocytes, blood vessels, and lymphatics within the bony matrix. All of these contribute to the maintenance and repair of bone. The periosteum is the fibrous connective tissue membrane that covers a bone. It has blood vessels that enter the bone, and it provides a site of attachment for tendons and ligaments. Bones are classified according to shape as long, short, flat, or irregular. In the elderly, esp. women, osteoporosis may develop, a condition in which bones become brittle and break easily. See: illustration; skeleton for names of principal bones

alveolar bone

The bony tissue or process of the maxilla or mandible that supports the teeth. Synonym: alveolar process

basioccipital bone

The basilar process of the occipital bone.

breast bone

Sternum.

brittle bone

Bone that is abnormally fragile, as in osteogenesis imperfecta.

cancellous bone

A spongy bone in which the matrix forms connecting bars and plates, partially enclosing many intercommunicating spaces filled with bone marrow. Synonym: spongy bone

carpal bone

One of the eight wrist bones, which are aligned in two rows. The proximal row contains (from the thumb to the little finger) the scaphoid, lunate, triquetral, and pisiform bones. The distal row contains (from thumb to little finger) the trapezium, trapezoid, capitate, and hamate bones.

cartilage bone

A bone formed by endochondral ossification developing from the primary centers of bone formation. Synonym: endochondral bone

cavalry bone

Rider's bone.

collar bone

Clavicle.

compact bone

The hard, dense bone made of haversian systems that forms the surface layer of all bones and the shafts of long bones, in contrast to spongy bone that forms the bulk of the short, flat, and irregular bones and the ends of long bones.

cotyloid bone

A bone that forms a part of the medial portion of the acetabulum during fetal development. It subsequently fuses with the pubis.

cranial bone

A bone of the skull or brain case.

cuboid bone

The outer bone of the instep bones of the foot that articulates posteriorly with the calcaneus and anteriorly with the fourth and fifth metatarsals.

cuneiform bone

One of the bones of the internal, middle, and external tarsus.

dermal bone

Membrane bone.

ear bone

One of the ossicles of the tympanic cavity: the malleus, incus, and stapes. See: ear for illus.

endochondral bone

Cartilage bone.

ethmoid bone

A complex thin-walled bone, roughly cuboidal in shape, located in the middle of the skull above the nasal cavities and below the anterior fossa of the cranial cavity. Its flat upper surface is the cribriform plate, which forms much of the roof of the nasal cavities; its upper surface has a midline bony keel that projects up into the cranial cavity and on both sides of which are perforated valleys through which the olfactory nerves project up from the olfactory epithelium. In the midline under the cribriform plate is a mirror-image (to the crista galli) keel, the perpendicular plate, which projects down between the nasal cavities as part of the bony nasal septum. The right and left sides of the ethmoid bone are the ethmoidal labyrinths, composed of ethmoidal air cells; the inner surfaces of the labyrinths form the middle nasal conchae, while the lateral surfaces form the orbital plates, which are part of the mosaic of bones that form the inner walls of the orbits.

frontal bone

The forehead bone.

funny bone

A colloquial term for the groove along the inner back side of the elbow (behind and underneath the medial epicondyle of the humerus) in which the ulnar nerve runs. Pressure on the groove compresses the ulnar nerve, producing a tingling discomfort on the inside of the forearm as well as the 4th and 5th fingers.

greater multangular bone

The first or outermost of the distal row of carpal bones. Synonym: trapezium

hamate bone

The most medial wrist (carpal) bone in the distal row. It has a hooked process on its palmar side. The hamate articulates with the 4th and 5th metacarpals. Synonym: hamatum; os hamatum; unciform bone

heel bone

Calcaneus.

hip bone

Innominate bone.

HYOID BONE

hyoid bone

The horseshoe-shaped bone at the base of the tongue. It is mobile and its ends hang by the stylohyoid ligaments from the styloid process on each side of the base of the skull. The hyoid bone is suspended by many muscles (the hyoid muscles): the suprahyoid muscles (geniohyoid, mylohyoid, digastric, and hyoglossus) attach the hyoid bone to the mandible and the floor of the mouth; the infrahyoid muscles (omohyoid, sternohyoid, and thyrohyoid) attach it to the larynx and the thoracic cage. The hyoid bone anchors and moves with the jaw, tongue, pharynx, and larynx. See: illustration

incisive bone

The part of the maxilla bearing the incisor teeth.

innominate bone

The hip bone or os coxae, composed of the ilium, ischium, and pubis. It is united with the sacrum and coccyx by ligaments to form the pelvis. Synonym: pelvic bone; os coxae.

interparietal bone

The squamous portion of the occipital bone.

interradicular bone

The alveolar bone between the roots of multirooted teeth.

intramembraneous bone

Membrane bone.

ivory bone

Marble bone.

lacrimal bone

A thin, irregularly shaped bone on the medial side of the orbit.

lesser multangular bone

The second in distal row of carpal bones. Synonym: trapezoid bone

lunate bone

Semilunar bone.

malar bone

A four-pointed bone on each side of the face, uniting the frontal and superior maxillary bones with the zygomatic process of the temporal bone. Synonym: cheekbone; zygoma; zygomatic bone

marble bone

An abnormally calcified bone with a spotted appearance on a radiograph. Synonym: ivory bone See: osteopetrosis

metatarsal bone

Any of the bones of the metatarsus. See: foot for illus.

membrane bone

Bone formed within embryonic fibrous connective tissue, in which fibroblasts differentiate into osteoblasts. Such bone is formed without a cartilage model and includes the bones of the face and cranium. Synonym: dermal bone; intramembraneous bone

mosaic bone

Bone appearing as small pieces fitted together, characteristic of Paget's disease.

nasal bone

Either of the two small bones forming the bridge of the nose.

occipital bone

The bone that forms the lower, posterior skull; it articulates with the parietal and temporal bones anteriorly, and the atlas inferiorly.

orbicular bone

The rounded end of the long process of the incus, a middle ear ossicle. It probably represents a secondary ossification center in the long or lenticular process.

palate bone

Palatine bone.

palatine bone

One of the bones forming the posterior part of the hard palate and lateral nasal wall between the interior pterygoid plate of the sphenoid bone and maxilla. Synonym: palate bone

parietal bone

One of two bones that together form the posterior roof and sides of the skull.

pelvic bone

Innominate bone.

perichondrial bone

Bone formed beneath the perichondrium.

periosteal bone

Bone formed by osteoblasts of the periosteum.

ping pong bone

A thin shell of osseous tissue covering a giant-cell sarcoma in a bone.

pubic bone

The lower anterior part of the innominate bone. It is a separate bone at birth; it begins to fuse with the ischium by age 8, and it is fully fused with the ischium and ilium by 16-18 years of age. Synonym: os pubis

replacement bone

Any bone that develops within cartilage.

rider's bone

Ossification of the distal end of the adductor muscles of the thigh, as may be seen in horseback riders. Synonym: cavalry bone

sacral bone

Sacrum.

scaphoid bone

The largest carpal bone in the first row of wristbones. It is on the thumb side of the hand and articulates directly with the radius. Synonym: os scaphoideum

semilunar bone

Crescent-shaped bone of the carpus. Synonym: lunate bone

sesamoid bone

A type of short bone occurring in the hands and feet and embedded in tendons or joint capsules.

Soemmering's bone

See: Soemmering's bone

sphenoid bone

The large bone at the base of the skull that has the ethmoid bone in front of it, the occipital bone behind it, and the parietal and temporal bones at the sides. It is shaped like a large moth. Its two broad, curved wings form the front walls of the middle cranial fossae, and its two “tails, ” the pterygoid processes, which hang in front of the neurocranium in the pterygoid fossa behind the facial skeleton. Between the wings, in the center of the body of the sphenoid bone, there is a deep, concave pocket (the sella turcica), in which the pituitary gland lies.

spongy bone

Cancellous bone.

squamous bone

The upper anterior portion of temporal bone.

stirrup bone

Stapes.

sutural bone

Wormian bone.

tabular bone

A flat bone, or one with two compact bone portions enclosing a center of spongy bone.

tarsal bone

One of the seven bones of the ankle, hind-foot, and midfoot, consisting of the talus, calcaneus, navicular, cuboid, and three cuneiform bones.

temporal bone

A bone on both sides of the skull at its base. It is composed of squamous, mastoid, and petrous portions, the latter enclosing the receptors for hearing and equilibrium. Synonym: os temporale See: Arnold's canal; mastoid; petrosa; styloid process

thigh bone

Femur.

trapezoid bone

The second bone in the distal row of carpal bones. It lies between the trapezium and capitate bones.

triquetral bone

The third carpal bone in the proximal row, enumerated from the radial side. Synonym: triquetrum

unciform bone

The hamate bone, the hook-shaped bone on the ulnar side of the distal row of the carpus. Synonym: os hamatum

wormian bone

One of the small, irregular bones found along the cranial sutures. Synonym: sutural bone

woven bone

Embryonic or rapidly growing bone characterized microscopically by a prominent fibrous matrix.

zygomatic bone

The cheekbone; the bone on either side of the face below the eye. Synonym: malar boneillustration

bone

The principle skeletal structural material of the body. Bone consists of a protein, type 1 COLLAGEN scaffolding impregnated with calcium phosphate hydroxyapatite crystals. As bone grows new bone is laid down immediately under the bone-covering membrane (periostium) and is absorbed from the inner surface. Oestrogens inhibit periosteal bone formation in women but promotes internal bone formation; androgens promote periosteal bone formation in males. The marrow of the flat bones are the sites of blood production. See also BONE MARROW.

Fig. 77 Bone . The shaded areas are lacunae occupied by osteoblasts.

bone

the skeletal substance of vertebrate animals, consisting largely of calcium and phosphate which make up 60% of the weight and gives it hardness. This ‘bone salt’, together with large numbers of COLLAGEN fibres, forms a matrix in which cells (OSTEOBLASTS) are distributed, and these are connected by delicate channels (canaliculi). Larger channels carry blood vessels and nerves (Haversian canals) and the cells are arranged concentrically around them. Haversian bone is found in the shafts of limb bones and is compact, whilst spongy bone is found at the ephiphyses (ends of bone).

bone

(bōn) [TA] Hard connective tissue consisting of cells embedded in a matrix of mineralized ground substance and collagen fibers. Fibers are impregnated with inorganic components, including crystals of calcium phosphate, such that using X-ray defraction, they are seen to be organized in a hydroxyapatite pattern (calcium phosphate is 85% by weight) as well as calcium carbonate (10%), and magnesium; by weight, bone is composed of 65-75% inorganic and 25-35% organic material; humans have approximately 200 distinct bones in the skeleton, not including the auditory ossicles of the tympanic cavity or the sesamoid bones other than the two patellae.[A.S. bān]

Patient discussion about bone

Q. Is a bone tumor cancer? My son is 10 years old and his Doctor found a tumor on his bone in an x-ray he did to him. Is this cancer?A. A bone tumor doesn't necessarily mean cancer. It could be a benign tumor and not a cancer one. Your son's doctor may then obtain a biopsy sample of the tumor. This involves taking a small sample of the tumor that can be examined in the laboratory to determine what kind of tumor it is. The biopsy can be obtained either through a small needle (needle biopsy) or through a small incision (incisional biopsy).

Q. is bone loss related to Arthritis? A. It depends on the kind of arthritis. In some arthritic diseases there's local bone loss, and generalized bone loss (osteoporosis) may result from steroids used to treat arthritic diseases.
You may read more here:
www.nlm.nih.gov/medlineplus/osteoporosis.html

Q. I have constant pain on my feet more on my bones than anything,do I have arthritis? I do already have plantar fascictisA. Chronic arthritis is a disease of the elderly and it isn't common to suffer from it in young age, however joint pain or bone pain can be caused by several other reasons, that might not be chronic, such as an infection, excessive physical activity or such. You should see a doctor to evaluate the pain and joint movement. He/ she might send you to do an x-ray to see if there's something they can see that is wrong with the joint or bone (dislocation or fracture).

More discussions about bone