Bone

There are also names for specific parts of long bones. Buttons are measured in lignes or lines, with 40 lignes equal to 1 inch. The joints can be affected by arthritis.
. Other illnesses are for example osteoporosis and bone cancer (osteosarcoma). Functional buttons for clothing became widespread with the rise of snug-fitting clothing in 13th and 14th century Europe. Bones heal by natural processes, but untended and unsupported can lead to misgrown bone. Buttons and button-like objects used as ornaments rather than fasteners have been discovered in the ancient Indus Valley (circa 2800-2600 BC), Bronze Age sites in China (circa 2000-1500 BC), and are attested in Ancient Rome.

One of the most common bone illnesses is a bone fracture. . It has been hypothesized that this is a result of bone's piezoelectric properties, which cause bone to generate small electrical potentials under stress.
. Repeated stress results in the bone thickening at the points of maximum stress. Buttons may be manufactured from an extremely broad variety of materials, including horn, shell, bone and antler, ivory, metal, plastic, celluloid, glass, thread, and wood. Its purpose is the release of calcium and the repair of micro-damaged bones (from everyday stress). Functional buttons work by slipping the buttons through a fabric or thread loop, or by sliding the button through a slit called a buttonhole.

Remodeling is the process of resorption followed by replacement of bone with little change in shape and occurs throughout a person's life. A button is small disc- or knob-shaped object attached to cloth or an article of clothing in order to secure an opening, or for ornamentation. In adults, red marrow is mostly found in the flat bones of the skull, the ribs, the vertebrae and pelvic bones. A bar is a row of perpendicular hand or machine stitching to reinforce the ends of a buttonhole. In newborns, all such bones are filled exclusively with red marrow (or hemopoietic marrow), but as the child ages it is mostly replaced by yellow marrow (or fatty marrow). A keyhole buttonhole is a worked or machine-made buttonhole with a round hole at the end of the slit to accommodate the button's shank without distorting the fabric; keyhole buttonholes are most often found on tailored coats and jackets. Marrow can be found in most any bone that holds cancellous tissue. A bound buttonhole's raw edges are encased in a piece of fabric or trim.

The diaphyses and the epiphyses of long bones remain separated by a growing zone of cartilage (the metaphysis) until the child reaches skeletal maturity (18 to 25 years of age), whereupon the cartilage ossifies, fusing the two together (epiphyseal closure). A machine-made buttonhole is usually sewn with two parallel rows of machine sewing in a narrow zig-zag stitch, with the ends finished in a broader zig-zag stitch. Secondary ossification occurs after birth, and forms the epiphyses of long bones and the extremities of irregular and flat bones. A worked buttonhole has raw (cut) edges finished with hand sewing, usually in a buttonhole stitch. They are responsible for the formation of the diaphyses of long bones, short bones and certain parts of irregular bones. Pairs of mandarin buttons worn as cuff links are called silk knots. Endochondral ossification begins with points in the cartilage called "primary ossification centers." They mostly appear during fetal development, though a few short bones begin their primary ossification after birth. Mandarin buttons are a key element in Mandarin dress (Qi Pao in Chinese), where they are closed with loops.

The formation of bone occurs by two methods: intramembranous and endochondral ossification. Mandarin buttons are knobs made of intricately knotted strings. Other factors present include GAGs, osteocalcin, osteonectin, bone sialo protein and Cell Attachment Factor. Worked or cloth buttons are created by embroidering or crocheting tight stitches (usually with linen thread) over a knob or ring called a form. Also making up the organic part of matrix include various growth factors, the functions of which are not fully known. Flat buttons may be attached by sewing machine rather than by hand, and may be used with heavy fabrics by working a thread shank to extend the height of the button above the fabric. It then associates into fibrils. Flat or sew-through buttons have two or four holes punched through the button through which the thread is sewn to attach the button.

This is made intracellularly as tropocollagen and then exported. Covered buttons are fabric-covered forms with a separate back piece that secures the fabric over the knob. The organic part of matrix is mainly Type I collagen. Shank buttons have a small ring or a bar with a hole called the shank protruding from the back of the button, through which thread is sewn to attach the button. The vesicles then rupture and act as a centre for crystals to grow on. This cleaves phosphate groups and acts as the foci for calcium and phosphate deposition.

Mineralisation involves osteoblasts secreting vesicles containing alkaline phosphatase. The matrix is initially laid down as unmineralized osteoid (manufactured by osteoblasts). The inorganic is mainly crystalline mineral salts and calcium, which is present in the form of hydroxyapatite. It has inorganic and organic parts.

The matrix comprises the other major constituent of bone. The iteration of remodeling events at the cellular level is influential on shaping and sculpting the skeleton both during growth as well as after. Osteoblasts and osteoclasts, coupled together via paracrine cell signalling, are referred to as bone remodeling units. These processes occur in tandem at site-specific locations and are known as bone turnover, or remodeling.

As bone formation actively fixes circulating calcium in its mineral form, resorption actively unfixes it thereby increasing circulating calcium levels. This process, called bone resorption, allows stored calcium to be released into systemic circulation and is an important process in regulating calcium balance. Upon arrival active enzymes, such as acid phosphatase, are secreted against the mineral substrate. Osteoclasts mature and/or migrate to discrete bone surfaces.

Because the osteoclasts are derived from a monocyte stem-cell lineage, they are equipped with engulfment strategies similar to circulating macrophages. These lacunae, or resorption pits, are left behind after the breakdown of bone and often present as scalloped surfaces. Osteoclasts are large, multinucleated cells located on bone surfaces in what are called Howship's lacunae. If osteoblasts can be described as bone forming cells, the osteoclasts can be described as bone destroying cells.

They possibly act as mechano-sensory receptors—regulating the bones' response to stress. Their functions include to varying degrees: formation of bone, matrix maintenance and calcium homeostasis. Osteocytes have many processes which reach out to meet osteoblasts probably for the purposes of communication. The space which they occupy is known as a lacuna.

However, osteocytes do originate from osteoblasts which have migrated into and become trapped and surrounded by bone matrix which they themselves produce. They are flattened, mononucleate cells which line bone. They function as a barrier for certain ions, induced osteogenetic cells. Bone Lining Cells (BLCs) share a common lineage with osteogenesis (bone forming) cells.

They contain alkaline phosphatase—a chemical which has a role in the mineralisation of bone. Active osteoblasts are situated on the surface of osteoid seams and communicate with each other via gap-junctions. Osteoblasts are mononucleate. They are located near to the surface of bone and their functions are to make osteoid and manufacture hormones such as prostaglandin which act on bone itself.

Osteoblasts are typically viewed as bone forming cells. Bone Heads include osteoblasts, so called Bone Lining Cells, osteocytes and osteoclasts. All bones consist of living cells embedded in a mineralised organic matrix that makes up the main bone material. vertebrae).

Irregular bones are bones which do not conform to any of the previous forms (e.g. the skull and ribs) consist of two layers of compact bone with a zone of cancellous bone sandwiched between them. Flat bones (e.g. finger bones) have a similar structure to long bones, except that they have no medullar cavity.

Short bones (e.g. In children, the bones are filled with red marrow, which is gradually replaced with yellow marrow as the child ages. The extremities of the bone are called the epiphyses and are mostly cancellous bone covered by a relatively thin cortical of compact bone. Surrounding the medullar cavity is a thin layer of cancellous bone that also contains marrow.

The central shaft of a long bone is called the diaphysis, and has a hollow middle—the medullar cavity filled with bone marrow. the tibia). Long bones are tubular in structure (e.g. Woven bone is often replaced by lamellar bone as growth continues.

In contrast lamellar bone has parallel fibres and is much stronger. It is so called because its fibres are aligned at random, and as a result has low strength. Woven bone is put down rapidly during growth or repair. Bone can also be either woven or lamellar.

Cancellous bone is trabecular (honeycomb structure), it has a relatively high surface area, but forms a smaller portion of the skeleton. Cortical bone makes up a large portion of skeletal mass; but, because of its density, it has a low surface area. Cortical (outer layer) bone is compact; the two terms are often used interchangeably. Bone can be either compact or cancellous (spongy).

Bone has an internal mesh-like structure, the density of which may vary at different points. While bone is essentially brittle, it does have a degree of significant elasticity contributed by its organic components (chiefly collagen). It has relatively high compressive strength but poor tensile strength. Bone is a relatively hard and lightweight composite material, formed mostly of calcium phosphate in the chemical arrangement termed calcium hydroxyapatite.

In the Stone Age bone was used to manufacture art, weapons, needles, etc. Ground cattle bone is sometimes used as fertilizer. Cut and polished bone from a variety of animals is sometimes used as material for jewelry and other crafts. The interaction between bone and muscle is studied in biomechanics.

Bones connect at joints by ligaments. Long bones can be connected to muscles via tendons. . The bones are then cleaned by hand, usually with a toothbrush and a degreaser.

Maceration is done by boiling fleshed bone with dish detergent and a little bleach until all large particles are off. Bones can be prepared for study by several methods, such as maceration. Bones and skeletons are studied in osteology. These evolutionary solutions are not completely functionally analogous to bone.

There are several evolutionary alternatives to bone. True bone is present in bony fish (Osteichthyes) and all tetrapods. In common parlance, cartilage can also be called "bone", certainly when referring to animals that only have cartilage as hard connective tissue, such as cartilaginous fish (Chondrichthyes) like sharks. Bone has a different composition than cartilage, and both are derived from mesoderm.

The bones of an animal are, collectively, known as the skeleton. Bones support body structures, protect internal organs, and (in conjunction with muscles) facilitate movement; are also involved with cell formation, calcium metabolism, and mineral storage. Bone, also called osseous tissue, (Latin: "os") is a type of hard endoskeletal connective tissue found in many vertebrate animals. Endochondral ossification occurs in long bones, such as limbs; the bone is formed from cartilage.

Intramembranous ossification mainly occurs during formation of the flat bones of the skull; the bone is formed from mesenchyme tissue. Porifera (sponges) possess simple endoskeletons that consist of calcareous or siliceous spicules and a spongin fiber network. A true endoskeleton (that is, protective tissue derived from mesoderm) is also present in Echinoderms. Exoskeletal protection is offered by shells, carapaces (consisting of calcium compounds or silica) and chitinous exoskelotons.