Day 1-2 (Cells, Matrix, Ossification, Density, Variation; Bone Classification; Bone Surface Features) Flashcards
What are the four tissues of the human body?
epithelial, muscle, neural & connective tissue
What is the function of each type of bone cell?
osteoblast-form bone
osteocyte-maintain or nurture bone
osteoclast- remodel bone
What is the primary constituent of the ground substance?
glycosaminoglycans
What is the principal type of protein fiber in bone?
collagen type I
What is the most frequently described deposit in bone?
hydroxyapatite
What is Wolff’s Law as it pertains to bone?
living tissue will respond to stressors; bone is formed or absorbed in response to stress
What are the three responses of bone which 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 mesenchyme?
intramembranous ossification
What is the timing for the appearance of intramembranous ossification?
from the second to third month in utero
What is the timing for the appearance of ossification in cartilage?
from the second to fifth month in utero
What part of the skull is derived from endochondral ossification?
chondrocranium
What bone of the appendicular skeleton is formed by both endochondral and intramembranous ossification?
the clavicle
What are the primary sources of variation observed in bone?
gender variation (sexual dimorphism), ontogenetic variation (growth or age variation), geographic or population-based variation (ethnic variation) and idiosyncratic variation (individual variation)
What is the characteristic feature of a long bone?
it is longer than it is across (length greater than breadth)
What are the names given to the parts of a long bone?
the diaphysis (shaft) and typically two epiphyses (extremities)
What is the primary characteristic of short bones?
they are essentially cubodial
What are examples of short bones?
most of the bones of the carpus and tarsus
What are examples of flat bones?
the parietal bone and sternum
What are examples of pneumatic bone?
frontal, ethmoid, maxilla, sphenoid & temporal
What is the characteristic of sesamoid bone?
the bone develops within a tendon
What are consistent examples of sesamoid bones?
patella and pisiform
What are the four basic surface feature categories?
elevations, depressions, tunnels or passageways & facets
When do the surface features of bone become prominent?
during and after puberty
