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