Flashcards in Bone Development Deck (11):
T/F: Intramembranous ossification involves a hyaline cartilage model precursor.
False. Endochondral ossification uses a hyaline cartilage precursor.
T/F: Intramembranous ossification takes place in long bones.
False. Intramembranous = flat and irregular bones
Endochondral = long bones
What is the first step in endochondral ossification?
The fetal hyaline cartilage calcifies and periosteal bone collar forms around the diaphysis.
Soon after formation of the bone collar, what forms in the diaphysis?
Primary ossification center
_______ ossification center forms in the diaphysis, while _______ ossification centers form in the epiphysis.
What parts of the hyaline cartilage are not replaced with bone during endochondral ossification?
Articular cartilage at the ends of the epiphysis, and the epiphyseal plates (growth plates).
What is the very last step of endochondral ossification that takes place at the end of puberty?
Epiphyseal plates ossify into the epiphyseal lines.
From epiphysis to diaphysis name the 5 zones of the epiphyseal plate.
Rick Pissed His Cat Off
Zone 1: resting cartilage
Zone 2: proliferating cartilage
Zone 3: hypertrophic cartilage
Zone 4: calcified cartilage
Zone 5: ossification
What is the pathway for storing calcium in bone?
High levels of blood Ca2+ -> thyroid gland releases calcitonin -> calcium salt deposit into the bone
What is the pathway for the release of calcium from the bone?
Low levels of blood Ca2+ -> parathyroid glands release PTH -> osteoclasts degrade bone matrix and release Ca2+ into blood