Anatomy & Physiology (BIO 425) - Chapter 7 Bone Tissue
medullary cavity
cavity within the shaft of the long bones filled with bone marrow
yellow bone marrow
fatty tissue found in the medullary cavity of most adult long bones
long bones
femur, tibia, fibula, humerus, radius, ulna, etc bones that are longer than they are wide act as levers
osteocytes
former osteoblasts that have become trapped in the matrix (lacunae) they deposited
red bone marrow
found in cancellous bone; site of hematopoiesis
ossificiation (osteogenesis)
the formation of osseous tissue
trabeculae
the irregular latticework of thin bony plates in spongy bone tissue
mineral resorption
the process of dissolving bone; osteoclasts dissolve bone minerals and they are released into the blood for other uses
osteology
the study of bone
osteogenesis imperfecta
inherited condition of deformed and abnormally brittle bones
open reduction
involves surgical exposure of the bone and the use of plates, screws, or pins to realign the fragments
articulating cartilage
layer of hyaline cartilage that covers the condyle surface of bones in joints
canaliculi
little channels that connect lacunae
orthopedics
prevention and correction of injuries and disorders of the bones, joints and muscles
endochondral ossification
process by which a bone forms from a preexisting model of hyaline cartilage (most bones develop this way)
intramembranous ossification
process by which bone forms directly from mesenchymal tissue
parathyroid hormone
raises blood calcium level; stimulates osteoclast production by osteoblasts
epiphyseal line
remnant of the epiphyseal plate, seen in adult bones; border of epiphysis and diaphysis
endosteum
reticular connective tissue lining the medullary cavity of a bone
bone matrix
rigid framework of bone that consists of tough protein fibers and mineral crystals 1/3 organic, 2/3 inorganic 85% hydroxyapatite (calcium & phosphate) composite (2 materials) - hydroxyapatite and collagen (flexibility)
spicules
rods or spines in spongy bone
diaphysis
shaft of a long bone
healing of fracture
1. Fracture hematoma formed from ruptured blood vessels; bone and other cells convert clot to granulation tissue 2. Soft callus forms (mixture of collagen and fibrocartilage) 3. Hard callus forms by mineralization of soft callus 4. Remodeling of hard callus to mature (compact and spongy) bone
spongy (cancellous) bone
Bone tissue that consists of an irregular loosely organized latticework of thin plates of bone called trabeculae; found inside short, flat, and irregular bones and in the epiphyses of long bone
osteoporosis
a condition in which the bones become fragile and break easily; loss of bone density
periosteum
a dense layer of vascular connective tissue enveloping the bones, except at the surfaces of the joints (hyaline cartilage)
calcitrol
active form of vitamin D; behaves as a hormone; raises blood calcium concentration by directing osteoclasts to liberate calcium and phosphate ions from bone
hypercalcemia
an abnormally high level of calcium in the blood
greenstick fracture
bending and incomplete break of a bone; most often seen in children
comminuted fracture
bone breaks into many fragments (3 or more)
displaced fracture
bone ends are out of normal alignment
nondisplaced fracture
bone ends retain their normal position
closed reduction
bone fragments are manipulated into their normal positions without surgery
osteoclasts
bone-dissolving cells found on the bone surface; develop from same bone making stem cells as blood cells (independent origin)
osteoblasts
bone-forming cells that synthesize the bone matrix
flat bones
bones of the ribs, shoulder blades, sternum, pelvis, and skull
short bones
bones of the wrist and ankles
irregular bones
bones that have complex shapes with short, flat, notched or ridged surfaces; examples are vertebrae that form the spinal column and several bones in the skull
skeletal system
bones, cartilage, ligaments joined tightly to for a strong flexible framework for the body
stress fracture
break caused by abnormal trauma to a bone
pathological fracture
break in a bone weakened by disease
osseous tissue
connective tissue in which the matrix is hardened (mineralization) by the deposition of calcium phosphate and other minerals
mineral deposition
crystallization process in which calcium phosphate and other ions are taken from the blood plasma and deposited in bone tissue
hypocalcemia
deficient calcium in the blood
epiphysis
end of a long bone expanded area at the proximal and distal ends of a long bone to provide increased surface area for attachment of ligaments and tendons
bone marrow
general term for soft tissue that occupies the marrow cavity of a long bone and small spaces amid the trabeculae of spongy bone, and larger central canals
compact bone
hard, dense osseous tissue that is beneath the outer membrane of a bone
calcitonin
lowers blood calcium levels: osteoclast inhibition osteoblast stimulation
nutrient foramina
minute holes in the bone surface that allows blood vessels to penetrate
concentric lamellae (compact bone) (osteon)
onionlike layers of matrix concentrically arranged around a central (haversian) canal (osteon)
central (haversian) canal
opening in the center of an osteon, carries blood vessels and nerves
lacunae
small cavities in bone that contain osteocytes
osteogenic cells
stem cells that give rise to most other types of bone cells
functions of the skeletal system
support protection movement electrolyte balance acid-base balance blood formation