Cells, Matrix, Ossification, Bone Density, Bone Variation Flashcards
What are the four basic tissues of the human body
epithelial, muscle, neural and connective tissue
What is osteology
the study of bone
What is the function of each type of bone cell
Osteoblasts- form bone
Osteocytes-maintain or nurture bone
Osteoclast-Remodel bone
What are the three primary cell types of bone
osteoblasts, osteocytes and osteoclasts
What are the bone cells embedded in
an amorphous matrix consisting of ground substance, protein fibers and various minerals
What is the primary constituent of the ground substance
glycosaminoglycans
What types of glycosaminoglycans predominate in bones
chondroitin sulfates, keratin sulfates and hyaluronic acid
What is the principal type of protein fiber in bone
collagen type 1
What are the primary constituents of the bone mineral
calcium, phospate, citrate and carbonate ions
What is the most frequently described deposit in bone
hydroxyapatite
Bone is also the repository for what additional ions
Sodium, magnesium, fluoride, lead, strontium and radium
What is Wolff’s Law
living tissue will respond to stressors; bone is formed or absorbed in response to stress
What are the three responses of bone that allow it to be described as “living”
it has the ability to heal, to remodel under stressors and to age
What is bone the embryological derivative of
mesenchyme or cartilage
What is the name given to the pattern of ossification in messenchyme
intramembranous ossification
What is the timing for the appearance of intramembranous ossification
from the second to third month in utero
What is the name given to the pattern of ossification in cartilage
endochondral ossification
What is the timing for the appearance of ossification in cartilage
from the second to the fifth month in utero
What part of the skull is derived from endochondral ossification
chondrocranium
Which bone of the appendicular skeleton is formed by both endochondral and intramembranous ossification
the clavicle
What are the names given to the centers of ossification based on time of appearance
primary centers of ossification appear before birth
secondary centers appear after birth
Mature bone is described as being composed of what areas based on bone density
cortical or compact bone and spongy, cancellous or trabecular bone
What is the name given to the bone below an articulating surface
subchondral bone
What is the name of the outer fibro-cellular covering of bone
the periosteum
What is the name given to the fibro-cellular lining of bone
the endostium
What are the primary sources of variation observed in bone
1) sexual dimorphism (gender variation)
2) ontogenetic variation (growth or age variation)
3) geographic or population-based variation (ethnic variation)
4) idiosyncratic variation (individual variation)
