chapter 6: bone development Flashcards
Intramembranous Ossification bones
flat bones: skull, clavicles, and mandible
development from fibrous embryonic membranes, directly from mesenchyme, no cartilage
intramembranous ossification
STEP 1 of intramembranous ossification.
osteogenic cells cluster along embryonic membranes and differentiate into osteoblasts.
What is the center of ossification?
starting point
where osteogenic cells cluster and differentiate
into osteoblasts
STEP 2 of intramembranous ossification
Osteoblasts secrete osteoid/matrix protein synthesis for export)
STEP 3 of intramembranous ossification.
Osteoblasts mature into osteocytes in lacunae. Calcium hardens the matrix.
STEP 4 of intramembranous ossification.
Outer layers become periosteum and compact bone
Inner layer becomes spongy bone.
What is endochondral ossification
When bones use hyaline cartilage for patterns
STEP 1 of endochaondral ossification. (hint: make cartilage template and protect it)
chondroblast formation.
stems cells turn into chondroblasts then chondrocytes to become hyaline cartilage.
Perichondrium develops around cartilage
STEP 2 of endochondral ossification. (hint: primary ossification)
blood vessels penetrate near middle: periosteal bud.
osteogenic cells differentiate to osetoblasts
osteoblasts secrete matrix and mature to osteocytes
Primary ossification occurs in which direction?
from bone surface to the inside of bone
STEP 3 of endochondral ossification. (hint: middle of bone)
removal of spongy bone by osteoclasts to make the medullary cavity.
STEP 4 of endochondral ossification. (hint: secondary ossification)
osteoblast migration from diaphysis towards epiphyses
epiphyses remain spongy w/out medullary cavity
hyaline cartilage remains as ____ ___ and
___ (growth) plates.
