Terms in this set (63)

  • red bone marrow
    the connective tissue within certain bones that produces red blood cells, white blood cells, and platelets
  • hemopoiesis
    the process of making red blood cells, white blood cells, and platelets in the red bone marrow
  • yellow bone marrow
    contains adipose cells that store triglycerides as a reserve of potential chemical energy
  • diaphysis
    the shaft, or main body, of a long bone
  • epiphysis
    the proximal or distal end of a long bone
  • metaphysis
    the region between the diaphysis and epiphyses that contains the growth plates
  • epiphyseal plate
    a layer of hyaline cartilage in growing bone located in each metaphysis that allows the diaphysis of the bone to grow in length
  • epiphyseal line
    the bony structure that results when the cartilage in the epiphyseal (growth) plate is replaced by bone at about ages 18-21, and bone has stopped growing in length
  • articular cartilage
    a thin, shock-absorbing layer of hyaline cartilage covering the part of the epiphysis where the bone forms an articulation with another bone
  • periosteum
    a covering that surrounds the external bone surface composed of an outer fibrous layer of dense irregular connective tissue and an inner osteogenic layer
  • medullary cavity
    a hollow, cylindrical space within the diaphysis that contains yellow bone marrow in adults
  • endosteum
    a thin membrane that lines the internal bone surface facing the medullary cavity
  • osseous tissue
    a hard connective tissue containing an abundant mineralized extracellular matrix that surrounds widely separated cells
  • hydroxyapatite
    a crystallized mineral salt in bone matrix that forms when calcium phosphate combines with calcium hydroxide
  • calcification
    the process where mineral salts are deposited in the collagen fiber framework, hardening the bone matrix
  • tensile strength
    this describes how the collagen fibers of bone enable it to resist being stretched or torn apart
  • osteogenic cell
    an unspecialized stem cell that is the only bone cell that can undergo cell division; the resulting cells develop into osteoblasts
  • osteoblast
    a bone-building cell that synthesizes and secretes collagen fibers needed to form the matrix of bone tissue
  • osteocyte
    a mature bone cell that maintains its regular metabolism, such as nutrient and waste exchange with blood
  • osteoclast
    a huge cell that releases enzymes and acids that digest the protein and mineral components of bone matrix
  • compact bone tissue
    the strongest form of bone tissue that makes up the bulk of the diaphysis of a long bone
  • central canal
    a space running longitudinally through an osteon of bone, containing blood vessels, lymphatic vessels, and nerves
  • concentric lamellae
    rings of calcified extracellular matrix layered around the central canal of an osteon
  • lacuna
    a small space between concentric lamellae which contains an osteocyte
  • canaliculi
    the tiny channels filled with extracellular fluid radiating in all directions from the lacunae, connecting them to each another and to the central canals
  • osteon
    a repeating structural unit of bone consisting of a central canal, concentric lamellae, lacunae, osteocytes, and canaliculi; also called a haversian system
  • interstitial lamella
    an area between osteons that is a remnant of older osteons that have been partially destroyed during bone rebuilding or growth
  • spongy bone tissue
    this consists of an irregular latticework of thin plates of bone called trabeculae, with spaces in-between filled with red bone marrow
  • trabeculae
    the irregular latticework of thin bony plates in spongy bone tissue
  • periosteal artery
    this enters the diaphysis of a bone through a perforating (Volkmann's) canal and delivers blood to the periosteum and outer part of compact bone tissue
  • nutrient artery
    this passes through a foramen in compact bone, and enters the medullary cavity, where it divides into proximal and distal branches that supply both the inner compact bone tissue of the diaphysis and the spongy bone tissue and red marrow of the epiphyseal plates
  • ossification
    the process by which bone forms during embryo and fetal development, growth from infancy through adulthood, remodeling, and fracture repair; also called osteogenesis
  • intramembranous ossification
    the process of bone formation in the flat bones of the skull and mandible, where bone forms directly within mesenchyme arranged in sheetlike layers that resemble membranes
  • endochondral ossification
    the most common bone formation process, which involves the replacement of hyaline cartilage (developed by mesenchyme) with bone
  • ossification center
    the cluster of mesenchymal cells that differentiate into osteoblasts at the site where bone will develop during intramembranous ossification
  • cartilage model
    the hyaline cartilage that takes the shape of the future bone during endochondral ossification
  • perichondrium
    an outer covering that develops around the cartilage model during ossification
  • interstitial growth
    growth from within a bone during endochondral ossification, resulting in an increase in the bone's length
  • appositional growth
    growth at the outer surface of a bone during endochondral ossification, resulting in an increase in the bone's thickness
  • primary ossification center
    during endochondral ossification, a region near the middle of the cartilage model where bone tissue replaces most of the disintegrating calcified cartilage
  • secondary ossification center
    this develops in the epiphyses of bone during endochondral ossification
  • bone remodeling
    the ongoing replacement of old bone tissue with new bone tissue
  • bone resorption
    the breakdown of bone extracellular matrix by osteoclasts that is part of the normal development, maintenance, and repair of bone tissue
  • bone deposition
    the addition of minerals and collagen fibers to bone by osteoblasts
  • open fracture
    describes when the broken ends of a bone protrude through the skin; also referred to as "compound"
  • closed fracture
    describes when the broken ends of a bone do not break the skin; also referred to as "simple"
  • comminuted fracture
    describes when a bone is splintered, crushed, or broken into pieces, and smaller bone fragments are found in-between the broken ends
  • greenstick fracture
    describes a partial fracture in children where one side of the bone is broken and the other side bends
  • impacted fracture
    describes when one end of a fractured bone is forcefully driven into the interior of the other end
  • Pott's fracture
    a fracture of the distal end of the fibula, resulting in a serious ankle injury
  • Colles' fracture
    a fracture of the distal end of the radius, in which the distal fragment is displaced posteriorly
  • stress fracture
    a series of microscopic fissures in bone that forms without any evidence of injury to other tissues, and results from repeated, strenuous activities such as running or jumping
  • fracture hematoma
    a mass of clotted blood that forms around the site of a bone fracture within 6-8 hours after the injury
  • fibrocartilaginous callus
    a mass of repair tissue consisting of collagen fibers and cartilage that bridges the broken ends of a bone within 3 weeks after the injury
  • bony callus
    this forms during fracture repair when the fibrocartilage is converted to spongy bone; lasts 3-4 months
  • closed reduction
    describes when the fractured ends of a bone are brought into alignment by manual manipulation, and the skin remains intact
  • open reduction
    describes when the fractured ends of a bone are brought into alignment by a surgical procedure in which internal fixation devices such as screws, plates, pins, rods, and wires are used
  • parathyroid hormone
    the most important regulator of calcium ion exchange that increases blood calcium level
  • calcitriol
    the active form of vitamin D (secreted by the kidneys) that promotes absorption of calcium from foods in the GI tract into the blood, helping to further increase blood calcium level
  • calcitonin
    a hormone secreted by the thyroid gland that decreases blood calcium level by inhibiting osteoclast activity
  • demineralization
    a normal effect of aging on bone tissue involving the loss of calcium and other minerals from the extracellular matrix, which reduces bone mass
  • osteoporosis
    an age-related disorder characterized by decreased bone mass and increased sensitivity to fractures, often as a result of decreased levels of estrogen
  • rickets
    a disease of children that results from inadequate calcification of the extracellular bone matrix, usually due to a vitamin D deficiency; growing bones become "soft" or rubbery and are easily deformed