Ossification Flashcards
what happens to new cartilage?
it is continuously being formed
what opens up a medullary cavity/marrow?
enclosed cartilage being digested away
builds bones
osteoblasts
what happens to older cartilage during ossification?
it ossifies or becomes bone
what happens to the cartilage for it to become bone?
gets covered by bone matrix and then its broken down
fetus has what type of bone
cartilage enclosed by “bony” bones
bones do what until growth stops
remodeling and lengthening
what two factors effect the remodeling of bones?
blood calcium levels and pull of gravity and muscles on skeleton
what replaces cartilage with bone?
osteoblasts
PTH
parathyroid hormone
what does PTH do?
signals to break down bones to get more calcium in blood if needed
how does gravity and muscle effect bones?
determines where the bone matrix is broken down or formed so the skeleton can stay strong
appositional growth
bones grow in width
what is growth controlled by?
hormones and during puberty sex hormones
when does bone growth end?
adolescence when epiphyseal plates are converted to bone (epiphyseal line)
